visualanalysis 17 user's guide · nodal load or apply member load command. 6. use the load...

1 Essentials

1.1 Welcome to VisualAnalysisIES VisualAnalysis is a general-purpose analysis and design tool for civil/structural engineers and related professions.Analysis is based on the finite element method. With over 22 years of IES development and tuning from thousands ofpracticing engineers, it can handle almost any structural problem. Using it should be easy, but mastering it mayrequire some reading!

Reference

Model (Section 2.1): Projects, model types, element types, sign conventionsLoad (Section 3.1): Load cases, combinations, and loadingAnalyze (Section 4.1): setup, theory, process, resultsDesign (Section 5.2): Design process, bracing, terminology, materials supportedReport (Section 6.1): Creating and managing reports, both text and graphics

Finding Your Way

Use the table of contents, index, or search to quickly get the information you need. Some key topics include these:

Start Here (Section 1.2): with a 5 minute TutorialVideo Training ('Video Introduction' in the on-line documentation): see the Table of Contents forvideosApplication Layout (Section 1.3): Menu, Panels, Mouse & KeyboardProject Files (Section 1.4): Working with .vap projectsBuilding Codes (Section 1.5): Optional in VisualAnalysis! Graphic Views (Section 1.6): Model View, Result View, Design ViewPreference Settings (Section 1.7): Customize VisualAnalysisPrinting Features (Section 1.8): Page Setup, Preview, PDFCustom Data (Section 1.9): More customization, how to share filesIntegration (Section 8.1): interactions with other programs or productsDisclaimer (Section 7.7): Use Sound Engineering Judgment

Upgrade Guide

If you are upgrading from VA 12.0 or prior, please read the Version 17.0 Changes (Section 7.2) or view thefull History (Section 7.1.1).

FAQ Answers

How to model a Plane Frame, or plane truss (Section 2.2)? Background analysis (Section 7.4) is slowing mycomputer?

Printable User's Guide

A PDF version of this User's Guide, that may not be 100% up-to-date is available.

Help Notation

Menu items are appear like this: File | New.Keystrokes or mouse commands appear like this: Shift+Click.VisualAnalysis is purchased in one of three levels; some topics are flagged like this:

VisualAnalysis 17 User's Guide

1 VisualAnalysis 17 User's Guide

http://www.iesweb.com/va/17/va-users-guide.pdf

Requires: Design Level

Requires: Advanced Level

IES is Committed to Your Success

VisualAnalysis is supposed to be friendly, robust, easy, practical, helpful, powerful, and ultimately useful for structuralengineering. If you find it difficult or confusing, or if you have crashing or performance issues we really want tohear about it. Please use the Technical Support (Section 7.3) resources!

1.2 Start HereNot only is VisualAnalysis a powerful, specialized tool for structural engineering, but it is also a standard Windowsapplication that follows most of the Microsoft User Interface guidelines. If you know how to use Microsoft Office, youwill find your way around VisualAnalysis very nicely. At the same time, there are some important issues of terminologythat will help you understand the documentation and spending a few minutes browsing this section of the User's Guidewill save you hours down the road as you get to know VisualAnalysis.

Learn VisualAnalysis in 5-Minutes!

The following steps will get you up and running very quickly. You might want to take a quick look at the Directing(Section 1.3) topic first to get your bearings.

1. Sketch members in the Model View by dragging the mouse. The nodes are created automatically at gridpoints. You can edit the Grid tab in the Project Manager to change the locations of "future" nodes.

2. Select items graphically with a mouse-click to edit them in the Modify tab of Project Manager. Usethe Ctrl key to "add" items to the selection set. Select "nothing" (click on the white-space in the Model View)to Modify the Project Settings.

3. Use the right-click context-menu for quick relevant commands pertaining to the view (Model View, ResultView, Design View) and what is currently selected. For a list of mouse commands that are available in the ModelView, right-click in the Model View, and choose Model View Help.

4. Use the Filter tab of Project Manager to toggle the display of all kinds of graphical information, such as thenames of members and nodes. But you don't have to clutter your view, hovering over an item providesinformation in the lower-left corner "Help Pane".

5. Loading nodes or elements is easy. Use the 2nd toolbar's drop-down list to select a Service Load Case,such as D (Dead Loads), L (Live Loads), etc. Then select one or more objects, right-click and use the ApplyNodal Load or Apply Member Load command.

6. Use the Load Case Manager to view or manage load combinations.7. In the Result View you can Filter on the display of all kinds of results such as member force colors or

diagrams, the displaced shape, nodal reactions, etc. Double-click on an item to get a report about what youare seeing.

8. Reports are easily generated from selected items (right-click) or predefined report templates, or by visitingthe Report View and using the Modify tab to add/remove tables from the report and define whether thereport should show all or selected objects of various types.

1.3 Application Layout

The Application Layout

Here is the default layout of windows and controls in VisualAnalysis. The major sections of the window are named foreasier reference later.



Please note that many of the screen elements can be collapsed, hidden, or moved to create a custom workingenvironment.

The Main Menu or Ribbon

The main menu, also called a Ribbon, contains over 100 commands to direct VisualAnalysis. Each is organized within agroup to help you locate them quickly. Some ribbon tabs only appear if you are working within a certain window. Eachcommand offers a description if you hover your mouse over it. Many offer hot-key shortcuts.

Context Menus

Most windows in VisualAnalysis provide a right-click Context Menu. This menu provides a relevant subset of thecommands in the main menu. Access this menu by using your right (or alternate) mouse button. (We normally think ofthis as a right-Click, but your mouse may be configured to swap the button behaviors.)

This should be your first choice when looking for a command because the available commands have been reduced to amore meaningful set. The commands in this menu are generally grouped according to their position in the main menuto help you locate them faster.

The Mouse

The mouse is a key component of the VisualAnalysis interface. You will use it extensively to sketch models, selectobjects, bring up the Context Menu, activate controls, and more.

The mouse becomes even more useful with the addition of mouse wheel support. The commands are documented atthe bottom of the table below.

If mouse commands are not working properly, or 'selection' is weird, you probably need to update your video carddriver!

To Click the mouse means to press and release a button. To Drag the mouse is to press a button and hold it downwhile moving the mouse. When you see Shift+ or Ctrl+ this means that you should press and hold the appropriatekey on the keyboard as you click or drag the mouse. Here are some of the commands available in most graphic views:



MouseOperation

Description

Clickor Left Click(Primary Button)

Selects a single item under the mouse cursor. All other items are usually unselected.Some multiple selection lists allow a single click to toggle the selected item without changing thestate of other items, making it easier to select many items.

If the Home | Zoom Area command is active this will either start or finish the creation of a"Zoom Box".

Right Click(Alternate Button)

Open the Context Menu (also called a popup menu). Also used to access "What's This?" help insome situations.

Shift+Click In a graphic view, selects all visible objects of one type. In a list, selects everything within in arange (Click the first item, the Shift+Click the last item in the range).

Ctrl+Click In a list or in a graphic view, it toggles the selection of the item under the mouse withoutaffecting the selection status of other items.

Shift+Ctrl+Click Selects items of one type with the same Name Prefix as the item clicked on.

Double Click In a Result View or Design View this will generate a Report View for the object.In the Find Tool window, double-clicking on an element or node item will cause the graphics toZoom to that item.

Drag [Drag is defined as holding a button down while moving the mouse.] In a Model View, this cansketch members, plates, cables or areas between grid points or existing nodes, dependingon the drawing mode.

Ctrl+Alt+Drag(Node)

Press the keys, then drag a node to move it. Works only if there is a visible edit-griddisplayed. You cannot 'merge' two nodes in this fashion. If you move the nodes so they arewithin your tolerance, you can use the Tools | Consolidate Nodes command.

Space+DragorShift+Drag

In a graphic view, draws a "Selection Box"—anything visible inside the box is selected.Everything else is unselected. The Space Bar method avoids "select all" issues when yourselection box would start on top of model objects, especially plate elements.

Wheel Rotation Zooms in or out of the model at the mouse location. In a list or text window, it scrolls.

Drag * Pan the model in a Graphic View by with a Click and hold on the wheel button, and draggingthe mouse.

Ctrl + DragWheel Mouse*

Rotates your view of the model in the direction of mouse movement. There are three styles ofrotation available, set in Preferences (Section 1.7).

Double ClickWheel Mouse*

Same as Home | Zoom Normal menu command.

*Note: Your mouse must be set up to interpret a wheel click as a Middle-Button, Windows lets you customize mousecommands through the Control Panel, Hardware, Mouse.

Keyboard Hot Keys

Shortcut keystrokes to certain menu or other types of commands. Note that some are not used (yet). Note too thatsome are context-sensitive, for example if an edit-control is actively accepting keyboard input then the copy, paste,delete and escape commands will apply only within that box. Note: Adding Shift to some commands will reverse theorder, such as increasing or decreasing the precision. You can see the hot key associated with a main menu commandin its tooltip.

Holding the Alt key will expose the hot-keys in the main menu.



Context menus also show hot keys. Other important hot keys include the following:

Hot Key Command Hot Key CommandShift + Arrow Pan the View Ctrl + Arrow Rotate the View

Ctrl+ [+] / [-] Zoom In/Out Del Delete (Graphic selection)

F9 Toggle Picture View Esc Cancel (Graphic drawing),Draw nothing mode

Home Zoom All or Full F Hold to temporarily show'Fly-by' information under mouse

Shift+F10 Context Menu Ctrl+C, V [C] Copy graphic image to clipboard.[V] Generate copies, or paste graphics in Report View

F7 Hide / Show Find Tool F1 Help

The Command Bar

The command bar provides important controls for the active Graphics view including a load case or result caseselector, a view orientation list, a named view drop-down, and the current project units setting. The bar alsocontains a few buttons to access the Load Case Manager, edit the active Load Case, or close a supplementarywindow.

There is a drop-down list of saved project reports, followed by saved report styles. Simply select one of these to displaythe report in the Report View.

The Project Manager

The Project Manager provides immediate access to frequent operations in VisualAnalysis. This tool is docked on the leftside of the window by default and displays five tabs at the top. If for some reason you do not see the Project Managerpress the F2 key or use the push-pin icon in the upper right corner of this panel. You may toggle this window if youneed more space to work, and it can be docked on the left or made to float independently—just drag the title bar. Youcan also drag the side border to make it wider or narrower.

The Create tab is used to draw models fast and create quick reports. It is here that you will find all of the new"generate standard" items.

The Modify tab is used to inspect or modify selected model and load objects, while a Model View is active.

The Filter tab provides many toggle switches and a few other settings to control what and how information is displayedin the active view.

The Grid tab controls the Sketch Grid to help you draw models in a Model View.

The Result tab replaces the Modify tab if a Result View is active. This tab provides key result information for the activeload case. Most of this information is also available in reports, but is displayed here for more convenient access as youinspect and verify your results.

The Cut Views tab allows users to work on specific areas of their projects through the use of Auto-Cut Planes andAuto-Cut Volumes. These allow you to view a 2D slice of a 3D model, for example.

The Find Tool

The Find Tool provides a very efficient way to view, select, and edit nodes, members, loads, load cases, design groupsand many other aspects of your model. This tool is docked on the bottom of the window by default. Use F7 orthe push-pin icon to auto-hide this panel. When docked, you may drag the side border to make the panel larger orsmaller.

The Find tool is especially powerful with more complicated projects. The Find tool will also allow you to find, select,edit, and delete objects even if they are not visible in the active window. If you double-click an element



(member, plate, spring) the graphics window can zoom-in to show that element, if it is visible.

Lists shown in the Find tool may be sorted by clicking on a column header, click again to reverse the order. You mayselect items just like any list in Windows using the Shift and Ctrl keys to select a range or to toggle individual items.The check boxes provide an alternate way to select items, clicking a check box is similar to holding the Ctrl key.

Saved Window Locations

VisualAnalysis will automatically remember your window and panel locations. Panels like the Project Manager or FindTool may be collapsed with auto-hide, or floated in a separate window. If your system changes, these saved locationsmay cause problems, such as a panel disappearing.

Reset Window Locations

You may reset your window layouts by holding the key down as you launch VisualAnalysis. If this doesn't work, or isdifficult, you may use the Tools | Custom Data command to locate the VA.DockingLayout.xml file and delete it.

1.4 Project Files

Open a Project File

To open an existing Project use the File | Open command. For a project you worked on recently you might find thefile on the quick list at the bottom of the File menu.

When you use File | Open, you will have a number of options regarding how the file will be opened.

Prior version project files are recognized and imported automatically. We do not attempt to read ALL information fromolder format files, but the model and loads in most cases will be preserved. Some features have changed significantlyand projects may get modified. You will get warnings or errors in some situations. If you have severe problems it maybe best to keep the old project in the older format and use a prior version of VisualAnalysis to work with it. You maysend a corrupt or broken project-file to IES Technical Support for further investigation.

Files can get corrupted, or VisualAnalysis might crash for a variety of reasons, if this happens, we hope you have asolid backup system in place, but VisualAnalysis does offer a quick and convenient backup safety net via history filesand timed backups.

Example Projects

We ship VisualAnalysis with a number of example projects files to demonstrate various possible modeling techniques.Some are extremely basic, others require that you have either the design level or the advanced level of the product.

Save a Project File

To ensure that your work is protected you should periodically save your project. Use File | Save to store theinformation in a VisualAnalysis Project File (.vap). Project files save your model and/or loads, analysis results, designinformation, and window layouts. Projects with results are much larger than projects without so you will want tobalance disk space with analysis time in deciding what to save.

Working with .VAP projects in Windows Explorer

When you double-click on a .vap project file, or right-click on it and choose Open, Windows will try to determinewhich program to use to open it.

If you have multiple versions of VisualAnalysis installed on your machine, Windows may get it wrong. You can right-click and use the Open With... command to select the correct version and to change the default. The most recentversion you "install" becomes the default for .VAP projects, but you can customize this in Windows Explorer. If you tryto open a newer .vap file with an older version of the product, you will get an error message and the operation will fail.

Another feature in Windows is to mark files as read-only. You can right-click on a .vap project file in Windows



Explorer and choose Properties from the context menu to mark it as read only, and then use a read only project like atemplate to "jump-start" new projects with some pre-existing model, load cases and combinations, and/or loads. Youmight want to put such files into a folder named "Templates" to remind you of their purpose.

Split Projects

VisualAnalysis does not offer specific features for dividing projects or models. You can often manually accomplish thetasks yourself, at least for basic models. You may wish divide a project into multiple parts if you are having memoryissues or other performance problems. You may also wish to divide the work among different engineers.

Open your original project file and delete the portions you want to remove, then use File | Save As to save thisportion of the project as a different file. Repeat the process with the original project file to split out a different fractionof the model.

Merging Projects

Combining two distinct .vap project files is more difficult than dividing a project into multiple parts. VisualAnalysis cantry to merge a project file into an open project using the File | Import | Merge VAP Project command. Basicmodel and load information will be merged. Objects may get renamed, location or direction collisions of data can causethings to change or fail.

You can also merge some basic modeling and loading objects from one project to another by using the ClipboardExchange (Section 8.7). This does not offer support for all features in VisualAnalysis, however, but may still save youtime over manually recreating items manually. You will need to be careful with naming of nodes and elements and loadcases. You may need to rename items in the 'clipboard' data or in the destination project before completing the import.

History Files

VisualAnalysis will create files to record multiple versions of a project file as you create and modify it. These backupproject files are called History Files and are saved with a name like "Your Project_Date.vap". These files can be usedto return to a previous state of the project. You might do this if you accidentally delete a file, it becomes corrupt, or ifyou have saved changes that you wish to undo. History Files are created every time you open a project file. HistoryFiles are saved in custom data folder (Section 1.9). This sub-folder is IES\Customer\History Projects.

The number of History Files or whether they are created at all are Preference (Section 1.7) settings.

Timed Backup Files

VisualAnalysis will optionally and automatically save your project every so many minutes (10 minutes is the defaultsetting). The Timed Backup file is automatically named "Your Project_Timed_Backup.va!". This file will be replacedwhenever a timed backup is made. If there is a crash in VisualAnalysis or your system this file protects your work up tothe last save point. When you start VisualAnalysis it will check for the existence of this files and if one exists you will begiven the opportunity to open it. Timed backup files are automatically deleted when you close a project successfully.

1.5 Building Code SupportVisualAnalysis incorporates optional and 'loose' support for IBC, and ASCE 7 and related building codes. This does notpreclude the use of VisualAnalysis for other building codes (e.g. IBC 2009 or IBC 2012) or foreign codes. Most of whatVisualAnalysis does (i.e., FEA) is outside the specific provisions of building codes. IBC itself consists of manyreferenced specifications as well as its own provisions. VisualAnalysis performs numerous functions according to thereferenced specifications listed below.

Loads

VisualAnalysis does not dictate or create loads automatically. There are some features for calculating ASCE 7 wind loadpressures, with lots of input from you, but you decide where and how those loads are applied.



Load Combinations

The building-code load combination (Section 3.6) system is optional and customizable to a large extent. You mayuse it or use your own custom combinations. From this perspective VisualAnalysis will support just about any code.There are a number of settings in the Project's Project Settings (Section 2.2) that will affect load combinations andsome design checks that are IBC-specific, but they are only used for the load combinations.

Seismic provisions in the project manager are used for generating load combinations only, they are not used in anyother way.

Material Design

VisualAnalysis has built-in support for AISC steel design (Section 5.4), ACI concrete design (Section 5.9), NDSwood design (Section 5.3), ADM aluminum design (Section 5.6) and NAS/AISI cold-formed steel design(Section 5.7). The specifications supported are listed in those sections.

Deflection Checks

IBC defines deflection-check (Section 5.1.2) categories for load combinations that VisualAnalysis will use, but youspecify actual deflection-limits for any category of load combination so this provides a very flexible way to checkdeflections that should allow virtually any building code to be employed.

1.6 Graphic Views

Window Types

VisualAnalysis can show you many different views of your model, loads, analysis results, and design results. You maychoose to work with one main window or you may prefer to have many windows open and available. The commandsdescribed in this section will provide useful tips for helping you manage these windows and to control the content eachview provides. Windows are managed using the Window menu commands.

Primary "Tabbed" Windows

Model View, for creating/editing models and checking element orientations, sizes, and materials.Result View, for inspecting, finding analysis results, and generating result reports.Design View, for unity checks, design sizing of members, and quick access to design reports.Report View, for your custom reports and system reports.Member Graph, for detailed deflection, moment, shear, and stress diagrams of member results.

Supplementary Windows

Influence Graphs, like a member graph, but may be for other objects as well as showing Moving Loadresults.

Determine What is Visible in a View

You can also show or hide objects based on the geometry of your model. See Cut Views & Volumes.

Rotating the View

View Cube Rotation

The easiest way to rotate your view of the model is to click on the "Cube" in the lower-left corner. You can click on aface, edge, or corner to orient the model.

Mouse-Wheel Rotation



Hold down the Ctrl key and the mouse-wheel (middle button) and drag the mouse around! See mousecommands (Section 1.3) for more details. There are three styles of rotation offered in the Preferences (Section1.7): Rotate "About Selected or Mouse", "About Model Center" (default), or "Last Point".

Menu Button Rotation

Use the Home | Rotate commands to "nudge" the view a little. These commands rotate in a positive or directionabout one of the global axes, you can hold the Shift key to reverse the direction of the rotation as you use thecommands. Use Ctrl+Arrow keys and to rotate the model about the X and Y axes, respectively. The nudge angle iscustomizable under Tools | Preferences. under the Filter section.

Pan the View

Hold the Shift key and use your mouse wheel held down like a button to pan the view left, right, up, or down. You can use Shift+Arrow keys as well. See Mouse Commands (Section 1.3) for configuring your mouse-wheelbutton.

Zoom In or Out

Now with Mouse Wheel support, just scroll your mouse wheel to zoom in or out of the model. Note that the model willzoom in or out at the location the mouse is at. For example, if you wanted to zoom in on a particular node, just holdthe mouse near that node and scroll the mouse wheel. The rest of the mouse wheel commands are documented inMouse Commands (Section 1.3).

Use Home | Zoom | In to bring the model closer or make it larger in the view. Home | Zoom | Out will make themodel smaller or appear farther away. The Home | Zoom | Normal command will restore the default view. Theentire model is made visible in the window. Hold the Shift key and click the Zoom Normal men item to zoom in onthe selected model objects.

Zoom a Specific Area

To get a closer view of a specific portion of the model, you can draw a Zoom Box around the area. This portion of themodel will be shown in the window. Use Home | Zoom | Area to start the procedure, the cursor will change whileyou define the area. You can click to define the upper left and then click again to define the lower right corner of a box.Alternately you can drag from one corner to the other.

For best results you should try to make the zoom box the same shape as the window. VisualAnalysis will not distort theinformation in the box to make it fit. Instead, the view will be expanded as necessary to conform to the windowdimensions.

The Search feature can also zoom in to the item you find, use Home | Find. If you double-click an element in theFind Tool window the graphics will zoom in to show that item.

View a 2D Slice: Cut Views

Working with 3D models can be very confusing if you try to view the whole model at once. One way to simplify things isto view only a "slice" of the 3D space. To do this, use the Cut Views tab in the Project Manager and choose anAuto-Cut Plane. Right-click on one of the auto-items to Regenerate Auto-Cut Views all the automatically createdviews, you might do this if you have changed your model significantly, or if you have changed units.

A cut plane or cut volume acts as a geometric filter. Anything entirely within the cut definition is visible and anythingoutside of it is not.

Cut Plane: Isolates a single floor plan or elevation in a typical rectangular frame.My Cut Views: User-defined "boxes" that may be oriented to match your structure! Lets you isolate morethan a plane, perhaps two floors and the columns between them. Right-click on this item to create a customview volume, or edit an existing one.

VisualAnalysis allows you to turn on multiple cut planes or volumes. You may also save & name any "auto" cut plane



and adjust its properties. Cut planes and volumes are used in Named Views to help you quickly return to a particularview of your model.

Clip to Selected

One easy way to define a Cut Volume is to select two or three nodes or elements in your model and choose Home |Clip to Selected. This command has the effect of automatically adjusting the Cut Volume settings to show objects inthe "plane" of the selected objects. Your cut volume is saved in the Cut Views tab of Project Manager under My CutViews. You can Right-Click on a cut view to edit its properties or rename it.

Use this command as a faster and easier way to define a custom cut volume for most typical situations. This commandis not available if the selected objects do not define a "box". For example, three collinear points define an infinitenumber of planes.

Filter by Object Names

A great way to simplify and organize large projects is to use a good naming system for nodes, members, plates andspring supports. You can filter a view to show only objects with certain types of names. Use the Name Filter area undereach object type in the Filter tab of Project Manager. Use the Structure | Rename command to help you definemember specific names in the first place.

A simple name filter might be a single character, "M". Think of this as saying, "Show me all the members whose namesbegin with a capital letter M."

Name filters are very powerful and you can be very creative in their use. The software will accept a list of name filtersand you can also use regular expressions for more control. For example, [^M] is interpreted to mean, "Show me all themembers whose names do not begin with a capital letter M."

The following table provides some of the symbols used to control this powerful feature along with some examples.Effective use of name filters requires some forethought when naming objects. Spending the time to setup a goodconvention right away will save you a lot of time later, especially with larger projects.

Symbol InterpretationCol Matches any name that begins with 'Col', exactly, case sensitive, such as Col001, Col002.

!B Negates the name. Matches any items that have names that do NOT start with B.

A, Bm (OR) Match names beginning with 'A' or 'Bm'

Animate a Result View

Result Views can show the deflected shape and you can animate this view by selecting the Home | Animate ResultView command when a Result View is active. For static results the animation will help you see where the structure isdeflecting. For dynamic results you have the ability to see real-time vibration behavior on top of deflections.

Sticky Notes

You can attach one or more text-boxes to the window or to a model object within the view. Right-click to get thecontext menu and add the note, you can edit the text of the note directly in the note.

1.7 Preference SettingsVisualAnalysis preference settings are default settings stored within a machine and primarily affect the behavior of newprojects. These are not project-specific settings (those are found within the Project Manager (Section 1.3)).Changes you make here will not affect other machines that you use to run VisualAnalysis, they are stored inthe Custom Data (Section 1.9) folder on your machine. You may access these settings through Tools |Preferences. Some changes do not take effect in an existing project or an existing report, some require you to exitand restart VisualAnalysis.



Restore All Defaults. Pressing this button will restore VisualAnalysis preference settings to their original settings. Thiswill not reset your custom shapes, materials, report styles or other data that you set up. This only affects items shownin the Preferences box, and similar automatic-settings (like report margins) and member graph styles.

Project

These preferences are for NEW projects, they do not affect the current project! Use the settings in Project Managerfor that.Vertical Axis: Specify which direction you normally use for "Up". VisualAnalysis defaults to (and generally works mosteasily with) +Y, but supports +Z or +X. CAD programs and Revit use +Z and if you exchange data frequently you canset VisualAnalysis accordingly. This setting will affect the orientation of members, which align themselves to the Y axis.

North Axis: This setting is displayed on "the cube" in the graphics, but otherwise has very little impact in the software.

Timed Backup Crash Protection

VisualAnalysis can periodically auto-save a copy of your project in the TEMP folder, this provides some protectionagainst a software crash destroying an hours work. The timed backup file is deleted when you successfully close aproject. If the software or the system crashes, the timed backup file is not deleted and is recognized when you restartVisualAnalysis. You will be prompted to open the file or delete it.

Project History Files

VisualAnalysis can create a series of project versions, one per day as you open an work with a project file. These arestored in your Custom Data (Section 1.9)\History Files folder. You might use these to recover a previous version ofa project in case you lose a project file to corruption or accidental deletion. (Open the Custom Data folder using theTools menu.)

IES provides this History mechanism as a feature, but you should take charge of your own backup system ofprotecting data files!

Data

Set the default name prefixes for nodes, members, springs, and plates, areas and area sides. These settings apply tothe first objects you create in a new project or immediately after restarting VisualAnalysis.

Reports

Changes things like headers and footers in reports, report margins and report related options. Many of the options arepretty self-explanatory but a few require a little clarification. Note that to edit any of the numerical values in thiswindow, click on the number once to select it, then click on it again to actually edit the value.

Warn if Reports >= N pages: If a report is greater than "N" pages, you will get a warning and a chance to cancelthe generation. With large models it is easy to create gigantic reports. For best results with larger models, createcustom report styles that filter the data so that reports stay manageable.

Member Output Sections: This value controls the number of member sections at which results are reported. Notethat this does NOT increase the number of sections that are analyzed. VisualAnalysis simply linearly interpolatesbetween analyzed points to obtain the additional values. To increase the number of sections per member that areanalyzed go to Project Settings, Performance. With some member result reports, you will NOT necessarily see theactual extreme values, setting this number higher will give you better results in the report at the cost of longer reports.If you are looking for extremes, find the RIGHT table to include!

Echo Input: Change the default for design reports. They can be shorter without echoing all of the design parametersused as input.

Conciseness: Control how much detail is displayed in design reports, by default.



Rotation Style:

About Selected or Mouse: Rotate about selected object(s) or the model object nearest the mouse.About Model Center: VA 12 style. Always rotates about model center (can be weird if zoomed in).Last Point: Rotate with any object(s) selected will set a rotation point, subsequent rotation is about thispoint. Reset the rotation-point using the right-click menu.

Fonts

Change the character size and styles used to display text in graphic views and reports. Click directly on the text toopen a font selection dialog.

Graphics

Sizes: Change how objects are drawn in graphic views.

Picture View: Determines the startup filter option for new projects.

Pan, Rotate, Zoom Amounts: Control over how much or how fast the view changes with mouse-wheel or arrowkeys.

Change Selection Size: When selected, objects may increase in thickness when selected, not just in color.

Draw Loads Away: Determines the direction of load arrows, relative to object loaded

Lighting: Adjust the light levels, may help with visibility issues not solved by color.

Design

Unity Success Limit: If you like to push the envelope, you can allow a slightly greater than 1.0 unity limit to bedefined as success. (You could use this to hide a 1% overstress in a graphical report you create for clients who don'tunderstand engineering, for example.) This setting will affect the current project, the next time unity checks are made.

Design Search Items: Applies to searching the database for members that meet design criteria, you can reduce thisnumber to improve performance or increase it to find more options. This setting will affect the current project, the nexttime a "design" command is issued.

Default to Sidesway Frames: Changes the defaults for column design groups.

Do All Checks: For performance you could uncheck this to get faster checks and shorter reports. But treat this like a'preliminary' design mode because it is quite possible to miss controlling design checks! This setting will affect thecurrent project, the next time unity checks are performed.

Auto-Groups: VisualAnalysis can guess how you want members grouped based on their materials, lengths,orientations, and more. It doesn't always get things right, especially if you have unusual structures, custom shapes, orwork with composite beams. If you don't like the automatic grouping, you may just turn it off by default.

Most preference settings are defaults for NEW projects, not for the current project, change the Project Setting toaffect how a specific project behaves, or change Design Group settings to affect groups already set up in a project!

Auto-Stress Checks: (Design level) For custom member shapes or materials, where the built-in design checks do notapply, you may use simple stress & deflection checking to get preliminary checks on members. This feature willautomatically generate design groups for members that are not already grouped (or cannot be). If you wish to usestress-checking exclusively you can turn off the Auto-Groups feature and turn this one on.

Auto-Connections: (Design level, requires IES VAConnect) VisualAnalysis will identify potential locations of steelconnections and group them according to geometry, shape types, etc. in the Design View. These groups provide thelink to IES VAConnect tools for base plate design, shear tab design and more in the future.

Deflection Limits

VisualAnalysis can check member deflections with a span ratio or an absolute limit, you can specify the defaults here forany one of four 'deflection categories' as defined in IBC.



Steel & Composite Beam

Composite beam design involves many input parameters. You can define defaults for many of these. Note that thesewon't affect any existing design groups in a project you have created, but will be used when a new design group iscreated in any project. These settings are self-explanatory or see the Steel Design (Section 5.4) reference for moreinformation.

Concrete

Concrete design involves many input parameters. You can define defaults for many of these. Note that these won'taffect any existing design groups in a project you have created, but will be used when a new design group is created inany project. These settings are self-explanatory or see the Concrete Design (Section 5.9) reference for moreinformation.

Aluminum

Buildings are checked differently than bridges, select your default construction type. You can also se the default forwhether or not to use heat affected material properties.

Colors

Change the colors of objects in Graphic Views and Reports. Every visible object type shown in graphic views have adefault color. For example, members are blue by default. If you find these colors difficult to see or just do not likethem, you may change them here.

1.8 Printing Features

Setup for Printing

Typically you can just print a report without any setup or modifications. There are many adjustable features for reportslike margins, headers, footers, and fonts. These are adjusted through Tools | Preferences, where you will normallyset them just once.

You can change the orientation of the page (portrait or landscape) using the File | Page Setup command. For moreadvanced formatting of reports, you might try saving it to a file and editing it with your favorite word processor.

You can change the orientation of the graphics page (portrait mode or landscape mode) using the File | Page Setupcommand before using the File | Print command. Note that a graphic window may consume a large amount ofmemory when printed. You may wish to print in draft mode for performance reasons or if printer memory is an issue.

Printing Graphics

There are two ways to print graphic views of your model, results, or design. You can use the File | Print (or PrintPreview) menu to create a one-page printout, or you can capture the image to the Windows clipboard using Home |Copy and Paste it into a text report or any Windows application that can accept bitmap images.

Printing Member Graphs

1. File | Print, or File | Print Preview, while viewing it. This respects the File | Page Setup margins.2. Home| Copy, then switch to Report View and Home | Paste. Here again, the image inserts in the report as a

“Clipboard Image” table (listed in the modify tab), and the image fits in the width of the margins for the report.3. Home | Copy, and then Paste it into any other Windows program, like MS Word or Excel. The image goes in

at the size of the window, but you can resize it or change layouts before printing.4. Use the Customize in the Modify tab of the Member Graph view, use the Export… button in the customize

dialog to save an image of a specific size and type. Use that image file however you like.



Print a Report

With a Report View open and active, choose File | Print to send the report to your printer. The File | Print Previewcommand will let you verify how many pages the report is and the exact layout. You may also use File | Save ReportAs to save the report to a file in plain text or rich text format.

Use File | Print to print the active Report View or File | Print Preview first to verify how it will appear.

Printing Problems

IES has tested printing to a number of different printers both local and networked and also to PDF writers includingAdobe Acrobat and CutePDF. If you have printing issues, make sure you have an updated printer driver. (This mayneed updating on the printer-server machine if printing across a network.)

You may need to adjust the printing defaults (quality, dpi, etc.), if there are out-of-memory issues. You can also changereport fonts in the Preferences (Section 1.7) if there are issues with the fonts installed on your machine.

Drivers

Out-of-date printer drivers can cause many problems. You can usually download the latest driver for your printer fromthe printer manufacturer's web site.

Quality or "dpi" (dots per inch): generally VisualAnalysis does OK with 300 to 2400 dpi settings. If you are trying toprint graphics, reducing the dpi setting on the printer may improve performance.

Bi-Directional Printing: There is a setting available on the Ports tab of the printer setting. If you have problemsprinting you might try toggling this option.

1.9 Custom Data Files

Open the Data Files Folder

VisualAnalysis is quite customizable and most of the customizations you make within the program or through other IEStools are stored in data files on a per-machine basis.

Go to Tools | Custom Data to open your data files folder in Windows Explorer. Manually navigate to this folder usingthe information below:

C:\Users\<your.login>\AppData\Local\IES\Customer

Things you will find in this folder include data for the following:

ShapesMaterialsReport StylesBuilding Code Load CombinationsLoad Helper Load DefinitionsPreference (Section 1.7) SettingsWindow LayoutsHistory ProjectsResponse SpectrumsTruck LoadsUnit Styles

XML Data Files

Many of the customizable data files are text files using XML (Extensible Markup Language). You may edit these filesmanually using Notepad. There are better editors available, including free tools like Notepad++, or XML Notepad,



which can provide color coded syntax and features for automatically completing the markup as you type.

Do not edit these files in MS Word or other tools that might change the format.

You generally do not need to manually edit any of these files, but it may provide an easier way to insert some newdata, remove something that is obsolete, or to merge files from two different machines.

Your Customized Data

Sharing Data with Others

If you customize a data file, you may share it with other engineers, users, or yourself on a different machine by copyingthe file(s) to the other machine, in the same folder. Depending on the file you may be replacing the existing file ormerging the new contents.

Own Your Data: Backup

If you make lots of customizations in VisualAnalysis, or manually, you will want to include the AppData\Local\IES folderin your backup plan.

Restore Default Data Files

You can reset the default data by deleting one or more of these files or an entire folder. You will then obtain thedefault file when you restart VisualAnalysis. For example, you can restore window/panel locations by deleting theVA.DockingLayout.xml file.

Installation

When we install VisualAnalysis, we install the default data files into an "All Users" location, then when VisualAnalysisruns, it copies these files (or updates them as necessary) in your "Local" data files location. This mechanism meansthat each user (logon account) on a machine has their own customized files, which are independent.

Uninstall

When you uninstall VisualAnalysis, these files are not removed. Corrupted data files could cause problems, so if youhave issues with weird behavior, you may need to manually remove data files before reinstalling the software. We referto this as a "clean uninstall", where you delete the following folders or registry sections (carefully!). You may want todeactivate your IES software licenses before performing a clean uninstall.

C:\ProgramData\IES

C:\AppData\<your.login>\Local\IES

HKEY_LOCAL_MACHINE\Software\IES

HKEY_CURRENT_USER\Software\IES

1.10 Shapes

IES Shape Databases

IES installs a number of proprietary shape databases such as those from AISC, NDS, or ADM. These may containcopyrighted information, so they are "tucked away" and you may not modify them. If you wish to suggest libraries ofshapes for IES to incorporate or make available, you may suggest those to IES Technical Support!

Custom Shape Databases

This system is a set of data files (Section 1.9) you have defined directly or imported or createdthrough ShapeBuilder (Section 8.1). Custom shapes will be available in VisualAnalysis as well as ShapeBuilder, and



perhaps other IES products. The system is flexible, and extensible, but OUTSIDE of VisualAnalysis.

Limitations

No composite shapes are stored in the database. Not all custom shapes will be checked using the design features inVisualAnalysis, see ShapeBuilder for details. The minimum properties needed for analysis are these: area, width, depth,moments of inertia, section modulii, and a torsion constant. Shapes with minimal properties are deemed custom blobs.

Format

The database consists of XML data files. If you are not familiar with XML, it is a text based format which is commonlyused for data-exchange, you can easily edit and understand them using a simple text editor. (We like "NotePad++"because it is freeware and offers XML syntax highlighting, but you can use any plain-text editor. Be careful with MSWord and similar as they may want to 'corrupt' the format.)

Shape Management

Please look for instructions and examples, in the Customer\Shapes folder. You can copy your database filesto other machines where you (or others) have IES products installed. You may delete any files you no longer wish touse. You may edit files to change data or to remove shapes or shape categories. You may copy these files from onemachine to another to share your customizations on different machines. You should take responsibility for these fileswith backup copies.

Legacy .DBS Database Files

Since 2013 with ShapeBuilder 7.0, IES started creating custom shapes in the new database. But you may havecreated shapes using ShapeBuilder 6.0 or directly from VisualAnalysis 12.0 (or prior versions). VisualAnalysis 17+ doesnot read these legacy (.dbs) files that are stored in your AppData\Local\IES\Data\Shapes folder.

Because that database did not contain enough information about principal section properties, there is currently noautomated way to import legacy .dbs files into the new system. You should manually create a new custom shape file. Ifyou need assistance getting your data converted, please contact technical support (Section 7.3), as we wouldlike to help, if we can.

1.11 Materials

IES Material Databases

IES installs a number of common material databases that we think are essential and useful to many customers. Thesematerials may not be modified or removed from the system. If you wish to suggest libraries of materials for IES toincorporate or make available, you may suggest those to IES Technical Support!

Custom Material Databases

This system is a set of data files (Section 1.9) you create and manage to add materials. Custom materials willbe used by VisualAnalysis, ShapeBuilder, and other IES products (except Quick- products). . The system is flexible, andextensible, but OUTSIDE of VisualAnalysis.

Limitations

All IES materials are assumed to be linear, isotropic and elastic. VisualAnalysis makes common use of orthotropicmaterials, like wood, but does so using isotropic properties! VisualAnalysis utilizes four primary properties: modulus ofelasticity, Poisson's ratio, weight density, and thermal coefficient of expansion. Materials like steel have a yield stress.Concrete has a compressive stress.

Data Format



The database consists of XML data files. If you are not familiar with XML, it is a text based format which is commonlyused for data-exchange, you can easily edit and understand them using a simple text editor. (We like "NotePad++"because it is freeware and offers XML syntax highlighting, but you can use any plain-text editor. Be careful with MSWord and similar as they may want to 'corrupt' the format.)

Material Management

You may edit the database files, manually, outside of ShapeBuilder. Please look for instructions and examples, inthe Customer\Materials folder. You may copy these files from one machine to another to share your customizationson different machines. You should take responsibility for these files with backup copies.

Legacy .DBM Database Files

VisualAnalysis 12.0 and ShapeBuilder 6.0 (and prior versions) used a binary format and different location(AppData\Local\IES\Data\Materials). There is no automated way to import legacy .dbm files into the new system. Youwill need to build "new" database files using your original data and the instructions and examples in theCustomer\Materials folder (see above). Materials are easy to define in the new system, so re-creating your materials isnot likely to be much of an issue.

1.12 Graphic FiltersWindow filters allow you to graphically show or hide various aspects of your model, results, or design checks. Eachwindow type has its own unique set of filter options, but they also share common filter choices. The Filter tab inProject Manager is where you access the filter settings. VisualAnalysis does not use the term layers, like many CADsystems do, but filter settings are similar.

You may also clip the graphic views spatially, using Cut Views (Section 1.6).

Common Filters

Title: Project title, billing, etc. useful for identifying printed copies of graphics

Axes: Show the global origin and global axes

Picture View: Use this filter option to turn on or off a 'rendered' view to show the actual shapes and orientations ofmember elements and the to-scale thickness of plate elements.

Highlight Report: Everything is shown 'ghosted grey' unless selected. This allows you to do a sort of filter-by-selection, or highlighting some aspect of your model or results, while showing context.

Fly-by Information: Provide popup window or tooltip textual information for objects under the mouse cursor.

View Cube: Toggle visibility of the rotation/orientation cube.

Name Filters

You can show or hide elements based on a name filter. Name filters are matched against a 'prefix' of the name of yourmodel object. Name filters are case sensitive. The following example examples illustrate how they work.

Member Filter Setting Effect on GraphicsB All members whose names start with the letter B are displayed

Bm, Col All members whose names start with Bm or Col are displayed

!C All members are shown, unless their name begins with C

Model Filter



In a Model View you can show or hide all model objects based on their type. You can also use name filters (see above).Textual details about each object can be toggled using the Details section of the filter. For example, under MemberDetails you can show the shape name, end releases, or local-coordinate system.

Color Mode: show model elements colors based on one of three modes. Please note that the color mode does notaffect all objects: nodes for example always use the default (preference) color.

Default Colors: Colors are based on the type of object and preference settings.Material Colors: Elements are displayed based on material-colors defined in the material database.Named Colors: Element colors are generated automatically based on first letters of object names. (Unnameditems have

Result Filter

The Result Filter lets you display element deflections, forces, or stresses by color, deflected shape, and reactions. Usethe Result Type object to show results for members, plates or other objects. You can turn on legends to explain thecolors, show extreme values as text and similar. For member elements you may show results as on-frame diagrams.There are also result filters for scaling the deflected shape.

If you turn use the Overlay undisplaced to show portions of the model view. When enabled you will also get a partialModel Filter to control how the undisplaced shape appears, for example to show it as a picture view or not, or to turnloads on or off.

Design Filter

The Design Filter lets you display information about design groups and the unity checks.

Toggle group is a selection mode that allows you to isolate individual elements in a design group or mesh. Usually it isconvenient to work with the whole group, but if you are trying to manage your own grouping, turn this option off.



2 Model

2.1 Model TopicsThe art of structural analysis and design starts with a simplified model of the real structure to be built. VisualAnalysisoffers one of the cleanest, friendliest environments available for constructing models of just about any civil/structuralproject, whether it is a simple beam or a complex industrial facility.

The Project

Structural Models (Section 2.2): Structure type, connections, Project Settings, performance, notes, units

The Model

Creating Models (Section 9.4): There are many ways to approach modeling in VisualAnalysisWorking in Model View (Section 9.3): Sketching, drawing mode, grids snap, extend, copy propertiesEditing Models (Section 9.5): Naming, move & rotate, split, etc.Nodes & Supports (Section 2.3): global coordinates, external supports, dynamic massMembers (Section 2.4): local coordinates, shapes, materials, options, results, etc.Plates (Section 2.5): local coordinates, meshing, sign conventions, results, convergenceAreas (Section 2.7): An object for defining loads, and generating plate meshesSoil Spring Generator (Section 2.9): A tool to generate spring supports underneath plate elements

Advanced Modeling:

Cable Elements (Section 2.6): true catenary shape Semi-Rigid Connections (Section 2.10): something between 'simple' and 'rigid'

Guidelines for Common Issues

Diaphragms: Use a Plate Element mesh (or meshed area) to model diaphragms with realistic stiffness

Composite Steel Beam Construction: Don't bother with the slab (unless desired for diaphragm behavior)

Limitations

Sorry, We Don't Do That! (Section 2.8) VisualAnalysis is designed for practical, everyday needs. It doesnot do everything

2.2 Project SettingsGeneral project settings are found in the Modify tab of Project Manager when nothing is selected.

Structure Type: Plane Frames or Trusses

VisualAnalysis offers one structure type, a Space Frame, with 6 degrees of freedom. These are indicated by DX, DY,DZ, RX, RY, RZ for translation and rotation, respectively. But your model may be planar, you simply need to THINKabout all 6 directions, just like in our real world.

You may easily model Plane Frames or Plane Trusses, by creating a 2D model and then Shift+Click a nodeto:

For a 2D Truss: fix all nodes in DZ, RX, RY, and RZ. For a 2D Frame: fix all in DZ, RX, and RY.



To model a Truss, use member end releases (Section 2.4) at each member joint. To model an ideal academictruss (no member bending) you could turn off self-weight that is automatically included in the "D" service load case,and avoid loading the members directly.

Project

Vertical Axis

You can select a direction to use for vertical. Up is assumed to be the positive coordinate direction selected. This willaffect self weight and certain building code load combinations, and graphic rotations. Members are oriented with a localcoordinate system that is always based on the global Y, for historical reasons. CAD projects often use Z for vertical, andVisualAnalysis can accommodate that.

North Axis

You can select one of the global coordinate directions (plus or minus) to be the North direction for your project. Thissetting is used in the automatic naming of model objects.

Coordinate System

You can select from displaying coordinates in Cartesian, polar, or spherical coordinates. Polar coordinates can beoriented in 3 different ways. Feel free to switch back and forth between the systems as you work with different parts ofa model. This affects how we display coordinate locations by default.

Risk Category

The risk category selection is only used for the automated building code load combination system, for seismic loadcombinations.

Analysis

Static Method

You can select from three different types of static analysis for your project

1st Order: linear or iterated (for one-way elements)P-Delta: iterated 2nd order analysisAISC Direct Analysis: P-Delta plus notional loads and reduced member stiffness

Mesh Element Area

Requires: Advanced LevelThis setting loosely controls how many plate elements get generated in all your auto-meshed areas. (The actualnumber generated will appear below.) Use this for mesh refinement as you work toward convergence.

Performance

You can adjust how many places along members where intermediate member results are calculated. This can have asignificant impact on analysis and design performance; however there is a trade-off with result accuracy. Generally, theAutomatic setting is a good balance. If you have performance issues, you can set it to Fast. If you want near perfectmoment and shear diagrams, without numerical round-off errors, you can use the Academic setting.

Advanced AnalysisRequires: Advanced Level

Neglect Nonlinear



You can use the setting to temporarily turn off nonlinear features and perform a linear analysis. You might do this tosee if your structure is stable without tension-only members, for example.

Lock Zero Stiffness

This is one way to handle numerical or instability issues, if you really know what you are doing. This is NOT the solutionto why most models become unstable. Look to your lack of nodal supports, floating or disconnected model objects, ortoo many end releases before you go fiddling with this setting.

Return Unconverged Results

For a limited buckling or push-over analysis. Turning this on allows VisualAnalysis to iterate a second-order analysisunder ever-increasing loads to find out which loading-level causes failure. When the numerical solution fails it may bean indication of buckling. For a true buckling analysis you may need to split members into multiple pieces to getaccurate results. Also, because VisualAnalysis does not handle material-effects such as yielding or crushing, the resultsmay not be conservative.

Force and Displacement Tolerance

Convergence of a nonlinear analysis involves looking at errors in both displacements and unbalanced nodal forces. Inorder for nonlinear analysis results to be acceptable, i.e. converged, these errors need to be smaller than a chosentolerance. For displacements, this is a unitless value and involves dividing the incremental displacement correctionvector norm by the total displacement vector norm.

Unbalanced nodal forces are calculated by taking the element forces that frame into a node minus the applied loadnode forces. These form a vector as well and the check is similar to the displacement check in that it is the norm of theunbalanced force vector divided by the total applied load vector norm (unitless).

Nonlinear Iteration Limit

Helps you work around pesky problems with convergence. Increasing the number will take more time, maybe morethan you have years available. Decreasing the number? Hmmm. You decide.

Load Stepping Points

Used for moving load analysis. Increasing the number might make your results more accurate. They will certainly takelonger than they already do.

IBC Seismic Loading

These settings are only used in VisualAnalysis to generate building code load combinations. They are all items definedin ASCE 7 (and referenced by IBC). Specify your Sds, Performance Category, Overstrength factors, and Redundancyfactors. FYI: No seismic loads are generated by VisualAnalysis.

Design Requires: Design Level

Auto-Group Members

Design groups can be created automatically for you based on the shapes, materials, and orientations of members in themodel, and the load combinations defined. The software will try to group like-elements into single groups. You mayalways delete design groups, remove members from groups, or create new groups manually. You can turn this optionoff to avoid generating any (or any more) design groups. Groups are generated automatically each time you switch toa Design View window, if this option is turned on and there exist members that are not grouped.

Auto-Stress Checks



For member shapes or materials that are not supported by built-in design types, you can perform generic stress-leveland deflection checking in the Design View. This option will automatically group ungrouped members for these kinds ofchecks. If you turn off the Auto-Group option, you can get stress checks for all members, even if VA could do morecomplete and specific types of checks.

Auto-Connection Group

If you have VAConnect installed this option will automatically create connection design groups where possible.

Metric Rebar Sizes

Concrete design groups will use the appropriate category (USA or Metric) when designing members. There is a defaultfor this option in the preference settings.

Export Results Type

When exporting connection-design forces to VAConnect or QuickFooting (Section 8.5) you can select whetherVisualAnalysis should export service case or load combination results. These results from VisualAnalysis become loads inthe design tool. Exporting of service case results is usually better for these tools, but if your project is nonlinear orcontains more sophisticated results that need checking, you may export the results as prefactored into these tools.

This setting has no effect on exports to VisualFoundation (Section 8.2), which always (and only) uses the service-level reactions.

Miscellaneous

Title is an optional descriptive name for your project. If left blank, the filename for your project becomes the title.

Billing Reference is an optional name or number used for your internal business purposes, this number will appear onreports.

Project Notes: Optionally enter a description, notes, thoughts, or information that you can include in a report and thatis saved with the project to help you remember what you need to do, or why you modeled something, or anything youneed to remember.

Nodal tolerance is used to control whether sketching, import, or copy & paste operations will generate a new node oruse an existing node. The default is very small (1/16th of an inch), but you can make this value larger to preventaccidentally creating nodes very close to other nodes. This setting is used in the Structure | Consolidate CloseNodes command.

2.3 Nodes and SupportsNodes serve a number purposes: they define locations of elements and provide an FEA link between elements. Theyalso function as external supports. Nodal supports are aligned with the global coordinates and are either free or rigid ineach direction (degree of freedom). If you need an elastic support, or a skewed orientation support, use a SpringSupport. To edit a node, select (Section 9.2) it in the Model View, and change the properties in the Modify tab ofProject Manager. You may edit many selected nodes at one time.

Global Coordinates

A global coordinate system is one that all entities in your structural model share. VisualAnalysis has a single globalcoordinate system available for this purpose and nodal coordinates are specified relative to the global system. Mostgraphic views show the direction and location of the global coordinate system, however if the global origin is not visiblethe global orientation is shown with dashed axes as shown. Global coordinates are always represented with theseupper-case letters {X, Y, Z,) or (R, Q; F). The Greek characters may be spelled out in places where special fonts are not



available: rho, theta, phi.

VisualAnalysis also uses element local coordinate (Section 2.4) systems that are distinct to each element. It isextremely important that you know the difference between element local coordinates and the global coordinates. Somedata (both input and output) is defined relative to the global system and other data is relative to an element's localsystem.

Nodes are entered and edited in global coordinates. These are Cartesian coordinates (X,Y,Z) by default, but polarcoordinates (R, Theta) and spherical coordinates (R,Theta, Phi) are also available in the Modify tab of ProjectManager.

Degrees of Freedom

Depending on the chosen structure type, nodes may move or rotate with respect to the global coordinate system. Theways a node can move or rotate are called degrees of freedom. In the space frame, nodes may translate in 3 directionsand they may also rotate about 3 axes. These are represented as DX, DY, DZ, RX, RY, and RZ for Displacement andRotation directions, respectively.

Creating Nodes

Generally you never need to explicitly create nodes as they are created automatically when you sketch members,plates, and cables or when you generate or import models. You can precisely position elements after they have beenimported and sketch elements to their correct locations in space using a Grid. There are instances where you may wishto manually create one or more nodes. This may be performed through using the Create tab in Project Manager anddragging the node item onto the Model View. See Also: 11 Easy ways to Create Nodes (Section 9.4)

Nodal Tolerance

As you create models, nodes are generated graphically or numerically. Sometimes due to round-off or grid locations orother issues two nodes will fall "almost" on each other but be slightly off. VisualAnalysis lets you control how closetogether nodes are before they are considered 'identical' and an existing "close" node will be used in place ofgenerating a new node. Use the Project Settings, Nodal Tolerance to define a tolerance that is reasonable for yourproject. The default is 1/16th of an inch, which may be appropriate for very small assembly models. A one-foottolerance may be acceptable for most building models. You should avoid setting this to a very large value--VisualAnalysis limits you to 36 inches--which might cause tolerance issues in strange places in the software.

If you think you have problems with duplicate nodes, you can adjust the Nodal Tolerance and then run the Structure| Consolidate Close Nodes command to find and merge duplicate nodes.

Free or Supported?

Most nodes in a model will be free from external supports. Nodal supports are used to restrain the entire structureagainst rigid body translation or rotations and typically are found at the bases of columns. Common supports are pinnedallowing no translation, or fixed allowing no movement at all.

First-time users of VisualAnalysis will often confuse nodal supports with "Joints" or "Connections" between members.Member connections are defined by the Structure-Type (Section 2.2) and also End Releases (Section 2.4) for amember. Supports are strictly "outside" restraint, like your structure sitting on a rock--the rock is a support.

Choose your supports wisely. A support should only be used at a location where load is taken out of the model or whereyou are specifying a nodal displacement. Do not support nodes at locations where you are applying external loads. Also,do not support nodes in directions where you have placed a spring support as this will render the spring supportineffective.

Scissor JointsRequires: Advanced LevelCommonly you will have two members that cross each other and are pinned together, like the joint in a pair ofhousehold scissors. In a real structure this can happen when one beam passes over the top of a girder, and in othersituations. Sometimes you do not want to go through the hassles of modeling the full 3D geometry.



A scissor joint is a finite element trick to save you the hassle of defining two offset nodes with a rigid link between themto get the proper behavior. Select the node where Members (Section 2.4) cross, and check the Scissor Jointoption in the Modify tab of Project Manager and VisualAnalysis does the magic for you.

Nodal Mass

Nodes may also be loaded with additional lumped mass (entered as a Force, convenient for most of using the Englishsystem of units). This mass is like self weight, but is ONLY used for dynamic inertial effects, it is not used in any staticanalysis. Self-weight of elements is defined by element properties and other dead loads should be applied as servicecase loads on nodes or elements. For more information about mass, see Dynamic Analysis (Section 4.6).

Nodal Results

Nodal results include displacements and rotations for unsupported degrees of freedom. In supported directions,reaction forces and moments are produced following the global coordinate sign convention, where a positive reactionis in the direction of the global axes (or the right-hand rule for rotations). If you apply a nodal settlement orrotation load to a node, that becomes the displacement results for that direction. Regardless, force reactions are stillcalculated.

Disconnected Nodes

Sometimes nodes can become disconnected to member elements, even though they lie at a coordinate that coincideswith the member element. This can occur when opening models created in different VisualAnalysis versions or othersupported file formats. It can become tedious to manually associate these nodes with the members that cross them. VisualAnalysis can automatically resolve these issues using the Fix Disconnected Nodes option in the Split Member(Section 2.4) dialog.

If nodes are created "loose" or orphaned and are not connected to anything at all you can find them using the Tools |Model Check command, as they tend to be graphically small amid the clutter of a complex project.

Spring SupportsSpring Directions: translation, rotation, allowed in any Degree of FreedomInclined Supports: supports not aligned with the global axesElastic Supports: supports with a specified stiffnessSpring Results: force, moment or rotationDetermine Soil-Spring Stiffness: stiffness is a function of supported areaGenerating Soil-Spring Supports (Section 2.9) (under plate elements)

Spring Directions

Translational spring supports may oriented along lines parallel to the global coordinate system and are specified bydirection cosines. When aligned with the global axes the cosines are either zero or plus or minus one.

Inclined Supports

VisualAnalysis offers pre-defined spring orientations for common directions like +X, -X, +Y, -Y, etc.. When enteringcosines you may use complex math expressions such as COS(3/SQRT(3*3 + 12*12)). You can use negative cosines,which is most useful for using compression-only soil-spring supports, or tension-only supports.

Elastic Supports

Spring supports are often used to model support conditions that are not truly rigid. For example, many soil-basedfootings have some elastic compression behavior that results in support settlement. When these cases exist, you mayplace a spring at the support node and set its stiffness relative to the soil elastic properties. More information oncalculating the stiffness is given in a section below. If you wish to model a compression-only support, you will need



to orient the spring in the correct direction to get the correct behavior.

Spring supports "take load out" of a structure and should be used as external support only. They are not used formodeling partially rigid connections between elements. To model a settlement at an elastic support, you should use aNodal Settlement Load.

Spring Results

Spring element output is based on the following sign convention. For displacement springs, a positive force is tension.Similarly, a negative force is compression. For rotational springs, a positive moment indicates the spring is beingtwisted according to the right-hand-rule.

2.4 Member ElementsMember elements represent frame or truss (Section 2.2) members in your structure. Member properties are shownor changed in the Modify tab in Project Manager (Section 9.2). You may edit many selected (Section 9.2)members at one time.

Local Coordinate System

Member elements each have a local coordinate system that is defined by their connectivity and orientation in the model.Local coordinates are always represented with lower case letters {x, y, and z}. The local system is aligned with theshape's principal axes. (Asymmetric members, like L and Z shapes, show a non-zero alpha angle which is the rotationfrom the geometric axes.)

The local system is used to define loads, end releases, and results.

The local x-axis is from the start node to the end node. The local y-axis originates at the start node perpendicular tothe x-axis and will lie in the plane formed by local x and a vector parallel to global Y. The local z-axis follows the right-hand-rule.

The picture shows the general and two special-cases:

Shape Orientation: Alpha and Beta Angles

Member shapes are oriented with respect to the shape's Principal axes, which may be different from the Geometricaxes. The geometric coordinate systems (e.g. x-y in the AISC manual), the principal coordinate system (often labeled as1-2), and a member element's local coordinate system (in VA this is z-y) are all related, but not always lined up theway you might expect. It has serious implications for orienting shapes, interpreting member results, and understandingwhat is meant by "Top" or "Bottom" in concrete design!

The rule for section orientation is this: The shape's major principal 1 axis is always aligned with the member



element's local z axis. Note: that shape dimensions can swap the orientation of principal axes, think of wide vs.tall rectangles!

Alpha Angle

Alpha is zero for symmetric cross sections. For asymmetric shapes, like single-angles, zees, or spandrels, the shape'sPrincipal axes do not line up with the Geometric axes. The angle between them is called alpha, and is a function of theshape's dimensions. We display this in the Modify tab for these shapes. All shapes in the shape database are orientedaccording to their Principal axes, so you may need to adjust the beta angle (-alpha) to orient the member with theGeometric axes. See member stresses below for more information.

Beta Angle

A Beta angle changes the default orientation of the local coordinate system and rotate the section properties of amember about the axis along the member's length. Positive rotation follows the right-hand-rule. Often you will rotatecolumn members 90 degrees, or asymmetric shapes by -Alpha to align the geometric and local systems.

Shape Properties

You define the size and shape of selected members through the Shape section on the Modify Tab of Project Manager.There are four types of shapes available for use in VisualAnalysis. You may also create custom shapes in IESShapeBuilder (Section 8.1) and add them to the shape database (Section 1.10).

Database Shapes

The most common type of shape used by civil/structural engineers are predefined manufactured shapes. IES includes alarge database (Section 1.10) of steel, wood, cold-formed, aluminum, and other shapes common in the USA andsome foreign countries. The database is customizable through using IES ShapeBuilder, not directly withinVisualAnalysis. Selecting a database shape will usually also define your material--most shape categories in the databasehave a default shape associated with them.

The shape database contains Virtual Joists and Virtual Joist Girders which are developed by the Steel JoistInstitute. There website has information on the basic concept and purpose. You may create models with these shapes,and get design-checks as if they were steel beams. Please understand their purpose and limitations before usingthem.

Standard Parametric Shapes

These shapes are defined by dimensions like width, depth, and thickness, which you provide. These types ofshapes are often used for concrete (square, rectangle, round) analysis. There is an infinite number of shape possibilitiesso it is easier to use the parametric definition rather than pre-building a list of possible shapes. Parametric Shapes aregenerally supported for design checks, however, there are some limitations. VisualAnalysis offers the following types ofparametric shapes: Square, Rectangle, Round, Pipe, I-Beam, Channel, Tee, Single Angle, Rectangular Tube, Zee, andSpandrel.



https://steeljoist.org/


Custom "Blobs"

Requires: Advanced LevelCustom blobs are a quick and dirty or academic tool. You define the member without a shape, just numerical propertiesfor analysis. In this way you can analyze any shape. You supply a name and it is available for use in the active projectonly. You cannot taper custom-blob members or design them.

Custom blobs should be used with care! The shape properties are not checked other than to ensure they arepositive. We use the moments of inertia and section modulus values to "back out" a depth and width for graphics.

Rigid Links

Requires: Advanced LevelRigid links are a finite element trick. They are simply a short, stiff member element used to connect two nodes at someoffset and to control the transfer of forces between elements framing into those nodes. By changing a member into arigid link, you let VisualAnalysis worry about the stiffness of the member. The only options on a rigid link are the end-releases. VisualAnalysis does a pretty good job of "hiding" these elements from your analysis results, reports, designchecks, etc, so you can focus on the real members in your structure. You can also use any member as a "rigid link" ifthe built-in one does not serve your purposes.

Quick Shape Pick List

The Modify tab of Project Manager shows the types of shapes available in the Source drop-down list: DatabaseShape, Standard Parametric, <Add Custom 'Blob'...>, followed by a list of shape names for shapes that are already inuse in your project. You can normally use this list to quickly find an existing shape in your model to use for a newmember element.

Material Properties

Material properties come from the IES material database, which includes most typical materials you might need. Toselect a material, use the [...] button in the Modify tab of Project Manager, to bring up the material selection dialog.All materials in VisualAnalysis are linear, elastic, and isotropic.

Select a shape before selecting a material! Most database categories have a default material that will be automaticallyassigned when you select the shape. If you specify the material first, your material may get replaced. To change thedefault material, right-click on the shape category when selecting a member's shape. Choose Default Material,select it, then right-click on the database name and use Save Database Changes..

Custom Materials

You can add new materials to your system by clicking the New Material button in the Material Selection dialog. Youmay also customize the material database (folders, design properties, etc.) by right-clicking on the Material Tree inthis dialog box. You can now specify any "design type" for materials making it possible to define custom wood, steel, orconcrete materials that will work for design checks.

Materials have certain design properties, so you should be careful to group materials in categories that make sense andbe sure to provide the necessary properties. The first step is to define the basic material properties: modulus ofelasticity (E), Poisson's ratio (nu, n), a weight density (gamma, g), and a coefficient of thermal expansion (alpha, a).These properties may not be zero, though you may use a very low weight density to represent a weightless material for



fictitious members (e.g. rigid links). If you are defining a steel, you need to add the Fy design property to your material,for concrete you need to add f'c, and for NDS wood you will need to define a number of allowable stress values andpick the correct design type! When you close this dialog box, any material database changes are saved. The ShearModulus, G, is calculated internally as: G = E / (2*(1 + nu)).

If you customize the material database you should take ownership of any modified database files. See preferences,files (Section 1.7) for the locations of the .dbm (material database) files.

Taper

VisualAnalysis supports a single or double linear depth variation along the length of a member. The defined shape ofthe member is the starting depth and the Depth2 value you enter is the depth at the other end or at the "end" of thetaper offset. The stiffness of the member is calculated based on the depth of the member at any point along the lengthof the member. The built-in taper is more accurate than using 100 "pieces" of member shapes!

You may optionally enter 'start x' and 'end x' offsets (measured from the starting node for the single-taper, and fromboth ends for the double-taper) for the variation. By default the offsets will be zero and the tapered Depth2 will be atthe far end of the member. This will allow you to create non-prismatic members with many profiles. The "bottom" tapercan be used so that the members draw differently in the graphics, but will not affect the numerical stiffnesssignificantly. Shown below are the "bottom" taper variations:

Tapering Limitations

Not all member shapes can be tapered. Standard parametric shapes and most database shapes that correspond toa standard parametric profile can be tapered. Cold-formed shapes, custom blobs, and double angles are examples ofshapes that do not allow tapering.

Members with crossings or intermediate nodes cannot be tapered. You must split members into individualelements in order to use tapering features.

There is no provision for tapering the width or flange-thicknesses of the shape, you would need to manuallysplit member elements and give each different shapes or properties to accomplish that.

End Connections, Releases

Member connections in a space-frame FEA structural model are infinitely-rigid by default. In other words, full force andmoment transfer exists between the member, the joint itself, and therefore to all other members framing into this joint.In some situations this is not realistic. A common situation in steel is the clip angle connection where little or nomoment transfer exists. In this case a moment end release should be placed at the joint.

On the Modify tab of Project Manager you may quickly define the most common end conditions using theConnection Type drop-down list. A type like "Simple-Rigid" means the 'start end' of the member is simple, the otherend is rigid. View the End Releases for the actual condition at each degree of freedom at each end. We use thisterminology for rotational connection types and end-releases:

Simple: rotation allowed for both Rz and Ry (local rotation), e.g., a shear-tab in steelRigid: no translation (Dx, Dy, Dz); or no rotation (Rz, Ry), e.g., a welded moment-connectionReleased: no restraint for a single degree of freedom (Dx, Dy, Dz, Rx, Ry, or Rz)

For more sophisticated analysis, using the advanced-level of VisualAnalysis, you can also create Semi-Rigidconnections (Section 2.10) between members for strong or weak bending, but these are rarely used or necessary.

To model a truss member, you can use the "Simple Connect" connection type or in a 2D model, use Rz releases. The member could still carry a moment due to applied loads or self-weight. You can prevent this by using a nearly



weightless material or not loading the member.

Realize that the convenient connection types may release weak-axis moments, making models less stable. If youhave stability issues you may want to remove the weak-axis releases in beam members. See My Model isUnstable (Section 7.5).

Other situations involving slotted holes may require force releases in the direction of the slot. Again, member endreleases are used for this application. To create advanced member end releases you may need to use the Connectionoptions of the Modify Tab.

Member releases are always specified in member local coordinates.

End Zones

Members connections in VisualAnalysis are modeled at their centerlines, which is normally accurate enough for mostproblems. In some cases however, you may wish to be more precise in your modeling. Member end zones, also calledpanel zones, allow you to account for a number of different situations you may encounter.

In structural steel connections, the beam to column joint is not totally rigid or totally flexible. The column may have athin, flexible web that will allow some additional rotation.

In other situations, say when a concrete beam frames into a very stiff wall or column, you may want to assume there isno rotation between the face of the support and the centerline.

In an attempt to approximate this behavior, a special end zone may be specified at the end of the beam element. Theend zone allows different member stiffness over a short region to linearly approximate the moment-curvaturerelationship. Internally, a short member element is inserted with modified properties.

To specify end zones enter the width, w, (along the length of the member) of each end zone and a percentage ofstiffness. This can be done on the Project Manager, Modify tab for a member. This percent factor multiplies themodulus of elasticity of the member when determining overall stiffness characteristics of the end zone member. Thereduced EI and EJ values have the effect of creating the partially restrained joint. If you select a rigid end VisualAnalysisuses a multiplier of 1000 on the member modulus to determine the end zone member stiffness.

Centerline Offsets

A common situation arises when plate elements are combined with member elements. The plate usually is placed ontop of the member and thus the beam centerline is offset below the plate element. Floor slabs, metal deck, and woodsheathing supported by beams are all good examples. The sketch below shows beams and girders aligned at the topflange. In order to model these effects you may use centerline offsets.

Centerline offsets affect the stiffness of the structure and the eccentricities can introduce moments or other forces intoyour system. Think of these offsets as short members that connect your offset member back to the centerline nodes.

Centerline offset lengths are specified in a local coordinate y or z direction, so a beta angle rotation will change thedirection of the offset.



Beam Top @ Nodes

This feature allows you to align all beams (members orthogonal to the specified vertical axis) with the associatednodes. The benefit to using this feature is you can specify node elevations as they might be called out on drawingssuch as a top of steel elevation = 100'-0". In order to do this, VisualAnalysis offsets the member using a Rigid Linkjust like using a Centerline Offset (above). Keep in mind that this will affect model statics and subsequently membermoments and forces, depending on specified boundary conditions. Specifying "Beam Top @ Nodes" and testing thetwo cases of a simply supported beam with end nodes pinned-pinned versus end nodes pinned-roller ( X-displacement "Free") will demonstrate the behavior of the rigid link used in this feature.

Optional: When you enable this feature you may optionally ignore any previously specified manual centerline offsetsfor beams. This insures all beams are aligned at the top. You can disable this option to allow your manual offsets to besuperimposed with the automatic beam offsets.

One-Way Behavior

Many situations exist where either supports or members are capable of having a force in one direction only.VisualAnalysis offers tension-only or compression-only elements to model these conditions. This setting is foundunder "Action" in the member's Options, and the default is "Normal (two-way)". A tension-only member is differentfrom a cable element (Section 2.6), which sags and can have pretension.

One-Way Option Disabled?

If this option is disabled, it is because (a) The member is Combined, (b) The member lies in the plane of an auto-meshed area, or (c) There is another nonlinearity in the project (e.g. P-Delta, Semi-rigid ends, etc...).

One-Way Examples

For example, soil is typically able to produce a compressive reaction only. When a footing uplifts from soil, thesupporting effect is gone. In this case you may use a compression-only spring support to model the soil. The stiffnessof the spring is normally calculated using the soil subgrade modulus multiplied by the area the spring supports.

Another example is a slender bracing member such as a rod that will buckle under a small axial compression, yet carrya large tensile force. In this case you may use a tension-only member to model this behavior.

Physical Members, Girders

In any finite element program, including VisualAnalysis, distinct elements and nodes need to be created along thelength of the girder for connecting these supported members. This necessitates dividing the girder into pieces. Forsimplicity in reporting and design, it is convenient to treat the girder as one single continuous member.

You may convert a chain of member elements into a single member using Structure | Merge Members. Similarlyyou may split a member into multiple pieces as necessary to achieve your modeling goals.

Connect Crossings, X-Braces

VisualAnalysis lets you take-charge of when members are connected to plates or nodes that intersect them. Use theConnect Crossings option in the member's properties to automatically split and connect the elements for analysis.You can use the Filter to show or hide where these automatic-nodes are generated when we map to the FEA model.There is a color preference for them as well.



X-Braces are normally best handled by not connecting, two member elements. This is especially true if you are goingto use tension-only members. On the design-side, you can use bracing settings (Section 5.1.3) to handle the factthat the members will physically connect and buckling will be prevented at the crossing.

Vertically Stacked Members

It is not uncommon to use beams that run "over the top" of other beams, so that they are stacked vertically. There areat least three ways you can model this situation, depending on how the members are loaded, what forces you want totransmit at the crossing, and how complicated you are willing to make your model.

1. Connect in the same plane, normally, and possibly use one or more end-releases. This is the simple approach,but may transmit torque or moments incorrectly.

2. Connect in the same plane, but use a scissor node. This allows in-plane movement or release, but would notprevent bending in the top beam from introducing torque in the lower beam.

3. Actually create two vertical layers in your model with the vertical separation. Then connect the two memberswith a vertical rigid link (or stiff member) with possible end releases at one end to limit the force transfer.

It may also be possible to model the top-layer of beams separately (if necessary) with supports or spring-supports torepresent the lower layer. And then simply apply the reactions from this model to the lower-layer model as loads.

Framing Type

Each member can be designated as one of three framing types {Beam, Column, or Bracing}. This setting is usedwhen area loads are applied to members, allowing you to exclude 'brace' members from picking up loads. Otherwisethis setting has limited effect, though it may be used more in the future. They are initialized automatically based on thevertical axis direction and the orientation of the member in space. You may override the setting at any time.

Results and Sign Conventions

Local Forces

Member local forces use the strength-of-materials sign convention. Tension is positive. Positive bending moment aboutthe z-axis causes tensile stresses on the negative y side. Positive bending moment about the y-axis causes tensilestresses on the negative z side. Positive local displacements and rotations are in the same direction as the positive localcoordinate directions or rotating about a local axis according to the right-hand-rule, respectively.

Local Deflections

Member displacements are reported with respect to the local axes (Dy is in the same direction as y, Dz is in thesame direction as z). Analysis deflections include the displacements of the end-nodes, if any! Span-ratio deflectionsare available in the Member Relative Deflections report.

Internal Stresses

Axial stresses are calculated assuming that the axial force, Fx, is applied at the centroid. Therefore fx = Fx/A where A isthe cross sectional area. Axial tension force and stress are always positive, while compression forces and



stresses are negative.

Shear stresses are calculated as a simple average over the entire cross section: fvz = Vz/A, fvy = Vy/A. The actual shearstress distribution or extreme stress is not calculated by VisualAnalysis. (You could manually estimate maximum shearvalues using formulas based on the shape profile: fvy_max = 1.5*Vy/A for a narrow rectangle, or Vy/Aweb for a wideflange, for example. Or you could use IES ShapeBuilder (Section 2.2) to determine shear distribution on a crosssection.)

Bending stresses are calculated and reported with respect to the local axes, which are assumed principal axes.

Stresses are reported separately for bending (fb) in each direction and for axial stress (fa). The bending stress is simplyM/S, and the axial stress is simply P/A, where M is the moment, S is the section modulus to the extreme fiber, P is theaxial force, and A is the cross-section area. Similarly shear forces are a strict 'average' V/A, without consideration of thevariation of shear on the cross section. For a detailed stress analysis on a cross section, you may wish to use ourShapeBuilder (Section 2.2) product.

The software will also calculate a corner or combined stress, fc, using a simple algebraic sum of the bending stressfor each direction and then superimpose the axial stress.

Be aware that if your shape is not rectangular or does not have physical fibers in the corners of the bounding rectangle(like a wide flange does), the corner stresses reported in VisualAnalysis can be very conservative, because they arecalculated blindly at 'fictitious' corners for L, T, Pipe, and other shapes.

Finite Element Formulation

The finite element used for member elements is a 2-noded prismatic (or linear depth-tapered) line element. Memberelements can be offset from their centerline and this is handled directly in the stiffness matrix. The axial displacementsare based on a linear displacement assumption and the transverse displacements are based on a cubic displacementassumption. Shear effects are included only for user-defined sections with nonzero shear areas. The stiffness matrix isthe standard found in most finite element textbooks. Special cases such as end zone are all handled internally usingmultiple member elements (creating an internal 'Combined Member').

Important Limitations: Member elements are a 1D element (a "line" without thickness) connections to elements aremade at the centerline, not at the "face"! Torsional stresses are not available, as part of the finite element analysis.However, if a member is twisted a torsional force is generated in the member, and nodal rotations can be used todetermine the twist. Warping behavior of thin-walled open steel cross sections can be analyzed ( with idealizedboundary conditions ) during the advanced steel torsion design (Section 5.4) process. VisualAnalysis does notperform 'buckling analysis', or 'plastic analysis' on member elements.



2.5 Plate ElementsPlate or shell elements are useful for modeling the stiffness characteristics of walls, slabs, roof systems or other flexiblediaphragms either in bending or in shear. Mathematically plate elements are thin, 2D areas that may be represented asquadrilateral or triangular shapes--they do not exhibit through-thickness stress variations like a 3D "brick element"would. Nonetheless, they are extremely useful for modeling many civil/structural problems.

While plate elements may be created manually, using an Area (Section 2.7) object with meshed plates is generallymore convenient. Auto-meshed areas require the advanced level of VisualAnalysis, but offers more flexibility withmodeling, separation of loads from plates, makes it easier to reconfigure your model or perform mesh refinement.

Unlike member elements for static analysis, plate elements (manual or auto-meshed) are always approximate: youmust use mesh-refinement techniques to know if you have enough plates in your model. Plate elements are rarelyused as single elements, but are more often used as a mesh; generally the more plate elements you use, the betteraccuracy you get.

Uses for Plate Elements

You can use a mesh of plate elements to model a concrete floor slab or you could use multiple meshes in variousorientations to model the flanges and webs of a wide-flange steel beam, perhaps to investigate localized stresses nearsome coping or holes. The use of plate elements is sometimes as much art as it is science and you are encouraged toget a good book on FEA modeling to understand some of the nuances.

Distributing loads is possible through a complex plate mesh--but NOT through a single plate element. A betterchoice for load distribution is an Area (Section 2.7).

You could use plate elements to model the stiffness of something that you are not really investigating directly. Forexample, you could model a flexible roof diaphragm with a minimal number of membrane-only plate elementsbetween the framing members of the roof to simply help the model hold its shape and transfer in-plane forces. In doingso you are not accurately modeling what is happening inside the diaphragm (which might be some very complexsystem of orthotropic materials or construction!), but you are modeling the overall behavior.

There is always a trade-off of performance vs. accuracy when using plates. The more you use, the better (generally).But the more you use, the slower the analysis, the longer your reports, and the more time it can take to manipulate andcheck your models.

Plate Element Formulation

A plate element will account for bending with transverse shear effects in thick plates and rotational drilling degrees offreedom. It is important to note that these formulations are not coupled during the initial analysis. The stiffness matrixfor each formulation is computed separately in local coordinate space. The two formulations are assembled into a total6 degree of freedom (DOF) global element matrix. Once assembled into the global element matrix, the element iscombined into the total structural stiffness matrix. Membrane and bending coupling is achieved with the addition ofgeometric stiffness terms in the overall stiffness matrix. The additional stiffness terms result from membrane strainswhich are calculated during the initial analysis. Once the membrane strains are found the element stiffness isautomatically updated to account for the extra stiffness terms resulting from membrane strains.

You can turn off bending behavior to create membrane-only plates, find the option in the Modify tab.

Both the membrane and bending formulations are based on triangular elements. When you use a quadrilateral element,internally four triangles are used with a middle node which is removed through static condensation thus creating thequadrilateral. Unlike in the past, with a constant strain formulation, triangular elements are very accurate inVisualAnalysis.

Bending: Thick-Thin Triangle (Xu)

The bending part of the plate element is now based on the triangle formulation originally presented by Xu et. al. in1992, which includes transverse shear effects. Prior versions of VisualAnalysis and many finite element analysis



packages use the discrete Kirchoff triangle (DKT) as their primary thin plate element. Although the DKT element is areliable and widely used element for plate analysis, it cannot accurately model thick plates. The new element accountsfor transverse shear effects present in structures that might contain areas with thick plates, such as footings or thickfloor slabs.

Xu, Zhongnian, "A thick-thin triangular plate element" International Journal for Numerical Methods in Engineering, v.33, 963--973 (1992).

Membrane Formulation: Allman Triangle

Drilling degrees of freedom, previously unavailable in VisualAnalysis, have been added to the plate element resulting ina 3-DOF per node plate element. This means that you may apply a moment perpendicular to the surface of the plateelement at any of the three (triangle element) or four nodes (quad element). Elementary membrane elements ignoredrilling dofs in order to avoid membrane locking. However, drilling DOFs are part of many structural engineeringproblems.

Membrane locking in the new element was avoided by independently interpolating the drilling rotations over theelement and introducing a penalty stiffness based on the shear modulus. The membrane element presented inVisualAnalysis is based on the early work of Allman. The element is similar to the standard CST membrane element butincludes an additional rotational degree of freedom at each node. We use 4-point symmetric integration using thepoints from Cook, which gives good results and matches the data from Allman's paper. Drilling DOF in membraneelements are difficult as all elements exhibit "membrane locking" and zero-energy modes, these issues can become veryprominent in coarse meshes.

D. J. Allman. "A compatible triangular element including vertex rotations for plane elasticity analysis.", Computers &Structures, 19(1-2):1.8, (1984).Robert D. Cook, Concepts and Applications of Finite Element Analysis, 4th Edition, Table 7.4-1, (2001) ISBN978-0471356059

Plate Thickness

You can safely model both thin and thick plates in VisualAnalysis. Thick plates automatically include the effects oftransverse shear deformations important for modeling foundations and footings.

Plate Shapes

Plate elements can be quadrilateral (4-nodes) or triangular (3-nodes) in shape. The element formulation is good enoughthat you do not generally need to worry about making the quadrilateral elements square. Elements may be distortedsignificantly without problems. We have run tests comparing the results of long thin elements and they work well—to apoint. For the very best results you should keep the element aspect ratios close to 1:1, but you should not expect anyproblems with ratios of 5:1 or even higher.

Plate Connections

Unlike member elements, plate elements are always assumed rigidly connected to the nodes in all directions. There isno provision for partially restrained (PR) or plate element releases at their connections.

For efficiency reasons, you should avoid situations where you have dozens, or hundreds of plate elements all connectedto a single node. This situation commonly happens at the center of a circular disk, with radially generated plateelements. You may wish to adjust the mesh near the center to alleviate the situation.

Plate Local Coordinate System

Plate elements have their own local coordinate systems. The local system has its origin at the centroid of the plate. Thelocal x-axis is parallel to and in the direction of a vector from the first node to the second. The y-axis is perpendicular tothe x-axis and in the plane of the plate. Note the right-hand rule where the local z-axis points out of the plane definedby the counter-clockwise node ordering. The picture below clarifies this, using a triangular plate element as an example.



For plate elements, the local systems are used for directing pressure loads. Local forces and stresses are also reportedin these directions. From a practical standpoint, it is usually necessary to be consistent in the creation of plates. Theconvention is to draw elements in a counter-clockwise manner, from the lower left. Generated plate elements inVisualAnalysis are usually oriented this way. You can use the Filter tab in Project Manager to show plate localcoordinates to verify their directions.

As mentioned, the local coordinate system becomes very important when applying plate pressures. If the plates arerandomly drawn in either direction the local z-axis will point in opposite directions and loading will become ratherdifficult.

Meshing, Mesh Refinement

One of the more difficult tasks you have as an engineer is to verify the validity of your results. Plate elements areapproximate—the more elements you use, the better your results. There is a tutorial project called Element MeshDemonstration, installed in the Examples folder, to demonstrate this concept.

Meshing is simply using multiple (many) plate elements to model a wall or slab rather than just one. You can draw oneand then manually split it. If you have the advanced level Auto-Meshed Areas (Section 2.7) offer many advantages.When manually creating a plate mesh, take care to align the elements such that the local z axes are all pointing in onedirection!

Determining a plate element size that gives accurate results and minimizes your model (and your time) is critical.VisualAnalysis uses a plate element with good convergence characteristics. Use the following procedure to minimize thenumber of plates in your models:

Plate Modeling Procedure

1. Start with an element size that matches the natural geometry in the model. Use nodes at locations where otherplates connect or where members connect. Try to minimize the number of plate elements in a reasonable way—do not bother with a single plate, though!

2. Run the analysis and record your results. If you have reason to question the results or if you have no way ofknowing whether or not they are reasonable, proceed to step 3.

3. Subdivide your initial element meshes into smaller elements. Structure | Split Plates makes this process easy.Analyze again with the refined model.

4. Compare the results of step 3 with the previous analysis. If the results are similar, assume you are near theconverged solution and feel somewhat confident of your results. Otherwise, if the results differ substantially,return to step 3.

How Many Plate Elements are "Enough"?

The following picture shows what happens as you "refine" your model by using smaller elements. Your goal is to getinto the "flat area" for the model, the area where results do not change much as you refine the model further.



As a general rule you will want to place more elements in areas where stresses and forces in the plates are changingthe most per unit length of mesh. Stress concentrations or locations near concentrated loads may require smallerelement size. At locations under uniform loading/no loading, and away from geometric irregularities, large elementsmay be sufficient.

Plate Results

Plates can report moment and shear forces for out of plane bending, and normal or shear stresses for in-plane activity.

Plate forces and moments are reported per unit length of plate, moments have units of force*length/length and shearshave units of force/length. Plate membrane stresses may also be output relative to the global or local axes.

Local Plate Results

The sign convention for moments: a positive moment produces tensile stresses on the +z local coordinate face of theelement, as shown in the sketch. This is typical plate notation as found in most texts on plate theory.



The picture below shows the sign convention for positive stress directions. As usual, positive normal stress indicatestension.

If plates in your structure can also bend, stresses may be reported at each of the top and bottom faces. Stresses at theface are combined bending and membrane stresses. If plates are subject to bending stresses only, the mid-plane is theneutral axis and therefore the normal stresses at this plane will be zero.

Global Plate Results

Plate forces and stresses may be reported with respect to the global coordinate system. This simplifies resultinterpretation when the local axes of elements in a complex mesh are not identically aligned. The global forces followthe right-hand-rule for sign convention. That is, a positive MX moment is at the global X edge of the plates and rotatesabout the global Z-axis. Some results may be zero after the transformation to the global directions, for example theglobal-Z moment for a mesh lying in the X-Y plane.

Plate results may be seen graphically in Result Views (Section 1.6), or in various report tables.

Yield Stress: Von Mises

The report for Plate Principal stresses includes the calculation of the Von Mises "effective stress" or yield stress:

"Von Mises" = (0.5*((s1 - s2)2 + s12 + s22))1/2

where s1 = principal maximum stress, s2 = principal minimum stress. Note that s3 in VisualAnalysis is zero becausewe are using a thin-plate element with no through-thickness stress, so the equation is simplified from the general one.

Meshed Plates vs. Manual Plates

VisualAnalysis can automatically create plate meshes, through Areas (Section 2.7), and this can greatly simplify thework you have to do in modeling. Automatic or meshed plates are managed by the system and will provide goodconnectivity with any members, manual plates, other meshes and nodes in your model. This is a huge benefit, greatlysimplifying the use of plate elements. It is not without drawbacks however. Here are some reasons why you might wantto use manually created plate meshes.

Meshed Plate Limitations



Auto meshes can be "ugly". If you have basically a rectangular area to mesh, you might just draw a singleplate element and then split it into a very nice rectangular mesh! This will automatically split borderingmembers, but will not automatically connect to members passing-through the plate (out of plane), nodesfalling on the interior of the plate area, or allow you to easily refine the mesh.There is currently no way to support an entire edge for an automatically generated plate mesh. You can insertsome nodes along the boundary and support them manually, but the mesh generator may insert additionalnodes between your supports and these nodes will not be supported, leading to "approximation errors".There is currently no way to provide spring supports under an automatically generated foundation slab mesh.

Convert to Manual Plates

Fortunately, you can take advantage of automatic meshing and then, when necessary "convert" an automatic mesh intomanual plate elements. Then you can deal with the above situations. Of course, once you do this, you lose themanagement ability of the automatic mesh.

Complex Systems

The finite element plate in VisualAnalysis is a "thin", flat numerical FEA device. It does not necessarily represent thethings we have to model in the "real world". How do you model the following complexities with plates? The answerdepends a lot on questions like:

How much time do you have?What answers are you trying to get from the model?How accurate does your model need to be?Can you account for complexities in other ways, such as design checks or rules of thumb?

Composite Systems, Wood Shear Walls, Masonry

Concrete walls or slabs are reinforced (we generally ignore this reinforcement during analysis), and will crack, forexample. Masonry systems have multiple materials and hollows. Wood shear walls consist of OSB panels with internalstuds connected with unknown nail-patterns: these are true "beasts" with orthotropic materials and nail-slip! Good luckcapturing that with a plate element. Modeling these kinds of systems will usually require you to make some seriousassumptions. Normally in a VisualAnalysis model, these things are providing general stiffness to an overall frame andyou are looking for how the forces distribute to beams, columns and foundations--not in the specific stress inside a 2x4in a stud wall. Once you determine the wall force you can then go and design your wall using some other tool orprocedure.

Stiffened Plates & Corrugated Metal Deck

These are a bit easier to deal with than concrete, masonry or wood systems. At least they are generally a singlematerial. The organization of stiffeners or corrugation causes the entire panel or system to behave in an orthotropicway, which you may (or may not) need to capture in the model. You can sometimes get away with distributing loadsfrom such a panel in a one-way fashion. In other cases you may need to use other devices such as creatingperpendicular 'rib' plates in your plate mesh, or thickening plate elements along the lines of the ribs, or using memberelements in the mesh to provide additional 'directional' stiffness. It all depends on what you are trying to learn from themodel.

Orthotropic or Anisotropic Materials

All materials in VisualAnalysis are linear, elastic, and isotropic. You may be able to approximate the behavior of othermaterials by using averages, or different materials in different plates, or by adding 'mechanical' stiffness (such as ribs).

2.6 Cable Elements



Requires: Advanced LevelCable elements sag, and are therefore unique due to their initial displacement and exhibit highly geometrical nonlinearbehavior. Cables do not carry shear or bending moments, only axial loads. Cables have a number of uses includingsuspension and cable stayed bridges, guyed poles and towers. This nonlinear element is highly sensitive toinitial conditions!

Limitations of Cables

Cables in VisualAnalysis assume that Y is the vertical direction, you must use this setting with cable elements.

Cable elements require self weight to function properly, therefore disabling or factoring self-weight will not have anyimpact on the cable elements, their actual weight is included in each service case or combination that is analyzed.

We recommend that you wait to split cables until geometry is fully defined. While VisualAnalysis does allowsegments of a cable to be edited after it has been split, there is no "knowledge" of its global identity. In other words, acable segment could sag within the overall cable as shown below. Obviously this does not make physical sense andshould be avoided.

Most manufactured cables are wire-rope assemblies that will untwist and stretch differently than a solid material.VisualAnalysis does not take this behavior into account.

Convergence During Analysis

Convergence can be a problem with cables. We recommend you use the Project Settings, Advanced Analysisoptions to Lock Zero Stiffness and Return Unconverged Results.

As previously mentioned, cables are geometrically nonlinear and the solution method is iterative. It is possible to applytoo large a load to a cable element and not have the analysis converge. In this case, you simply need to apply asmaller load and re-run the analysis. Cables are also unique in that as you load them they become stiffer and carrymore. As VisualAnalysis analyzes a cable element, it may first cut the load back until it gets a solution. As the analysisproceeds with each iteration, it may then increment the load back up until it reaches the total applied load. If it cannotreach the total applied load, it will give you results for the last largest load that it found a solution.

Also related to the nonlinearity of cables is the limitation that you cannot obtain mode shapes for cables or othernonlinear problems in VisualAnalysis. Remember, many principles that are valid in the linear realm are not valid in thenon-linear realm (superposition, etc.).

Reporting Cables

Reporting cable results is very similar to reporting member results. There are two main report categories for cables:Cable Elements and Cable Results. The cable elements report includes all the typical cable element properties such asthe material, end nodes, weight, catenary length, etc. The cable results report includes the reported cable,displacements, axial force, and axial stress. The usual reports are available which include the double-click report or youcan always create a custom report using the report wizard.

Strange Deflected Cable Shapes?



An upward arc type displacement may be seen in long cables that have been split into several sub cables. Thisis normal. When you use the large displacement magnifiers like the default 0.2 factor in the Filter, the displacedshapes might look unreasonable. If you encounter this, set the Amplification Type to Absolute and the AbsoluteAmplification to one (1) to see the true deflected shape.

Using Cables

In the advanced level of VisualAnalysis, cables are treated as separate element types like members and plates. Cablesare fairly easy to specify, but difficult to model and understand (see above)! Draw a cable between two end points anddefine the catenary length of the cable, which is different than the straight-line distance between the nodes. The cablewill sag under its own weight, you can adjust the amount of sag by adjusting the catenary length.

If you define the catenary length shorter than the straight line length, you apply a pretension or prestress to thecable. There is no way to specify pretension directly, you must back-calculate it from the "stretch" using Hooke's law.

Modeling

Cable cross-sections can be defined using standard round shapes or selected from the shape database. IES has addedsome common cable cross-sections to the database, however there are many more available from manufacturers thatcan be added to the database using the ShapeBuilder. Another item to keep in mind is that Y is always considered thevertical axis for cables. This is important as it defines the cable's sag.

Loading?

Cables do not carry shear or bending moments, only axial load. Cables may only be loaded with concentratednodal loads. Because of this, cables must be split before a concentrated load is to be applied along the span.

Splitting Cables

As mentioned previously, if a concentrated load is to be applied to a cable it is necessary to split the cable. A cable issplit using the Structure | Split Cable command, much like splitting members.

Essentially there are three options for splitting cables: equal segments, equal horizontal projections, and specifiedlengths. For the equal segments and equal horizontal projections options, simply specify the number of desiredsegments. For the specific lengths option, specify the length as measured on the cable from the start of the cable, withthe exception of the last segment. The last segment will automatically become the remaining portion of the cablelength.

Results

Analysis of cable members is performed much like any other element in VisualAnalysis. One exception and note ofcaution is to check the results very carefully. After a cable analysis is performed, an Analysis Diagnostic report willimmediately appear. It may be reported that the analysis was completed successfully; however careful attention shouldbe taken to observe the largest load for which a solution was found. The completed analysis may not have used thefull applied load.

Cable References

Nonlinear Static and Dynamic Analysis of Cable Structures by by Huu-Tai Thai, Seung-Eock Kim. Finite Elements inAnalysis and Design. 74 (2011) 237-246.

Some Modeling Aspects in the Nonlinear Finite Element Analysis of Cable Supported Bridges by Raid Karoumi. Computers & Structures 71, 397-412, Copyright 1999.

2.7 AreasAreas represent a meta-level finite element object. Areas are useful for separating the definition of loads from the



definition of low-level member or plate elements, which may change over the course of modeling. They provide supportfor distributing those loads to elements and allow you to generate plate element meshes to represent actual structuralfloors, walls, or roof systems.

Creating Areas

Areas are created by sketching them in the Model View. Select the Draw Areas mode from the Structure ribbon tab.Sketch the area just like you would a plate element except that you can have any number of vertices (Click & drag todefine the first edge, then click subsequent points (either grid points or existing nodes) to define subsequent edges. Toclose off the area, double-click or click again on the original point.

Area Local Coordinates

Areas have a local coordinate system that is defined by the first two vertices you sketch, just like a plate element! TheNormal direction is the perpendicular (or local z) direction that forms a right-handed coordinate system. The sketchbelow shows how the local x lines up with the first two "nodes" or vertices. There is no way to reverse the normaldirection of an existing area, so you should be careful when constructing similar areas to define them with their normal-axes aligned, this will ensure that similar loads are in the same direction.

You may create area vertices at any grid point. For any area vertex, there does not need to be a node (or elements) inyour model near this point although normally your areas will align with your model. Sometimes they may extendbeyond the model or lie interior to your model. You may also create "skewed" direction areas that align with a slopedroof or a building wall; they need not be aligned parallel to a global axis.

Areas are defined by vertices and not nodes. Vertices may be located at the same place as a node in your model, butdo not depend on that node or follow that node if it is moved. You create vertices automatically when you sketch areas,but nodes are not created in this fashion. If you wish to have a node in the same location as a vertex, you may right-click on the vertex to Create Node at Vertex Location. There is no way, currently, to tie the vertex locations to thenode locations, so if your nodes need to move, you will need to move your areas separately.

Areas may be selected and deleted just like any other model object.

Areas have no mass, no stiffness, and offer no constraints or support in your model. Areas are, in fact, not part of thefinite element model that gets analyzed, but a higher-level representation of a floor, wall, or roof system in your modelused primarily for loading the actual elements in your model. It does not make any sense to create an area withoutcreating member or plate elements for the structural model. Your model must be complete and stable--independently ofany areas that you define. You must also ensure that a valid area is created with area edges that do not cross. Areasshould not "overlap" each other in the same plane as this could lead to undefined behavior in the software.VisualAnalysis will normally prevent this from happening, but you should know just in case you slip past our defenses!

Generating Areas

Use the Structure | Create Areas Automatically to search through your model for good locations for areas. In atypical rectangular building model you would obtain areas for the four exterior walls, and one for each floor plan. Theareas generated may not be perfect (and indeed your exterior areas will likely not extend to your base nodes as therewere no bounding members between them), so you may need to adjust them, or remove ones you do not want.

A more refined approach is available. Select three, four, or more nodes to define the "corners" of a new area and usethe Structure | Create Area through Selected command. This will generate a single area in the plane defined byyour selected nodes.

Modifying Area Locations



Areas are defined by vertices, not nodes, and therefore do not automatically "track" movements or changes in yourstructural model. You can use the Filter tab to display Area Vertices--and you may wish to turn off other items so theyare easier to work with. You should normally define areas after your model configuration has been fairly welldetermined! If you move nodes around, your areas may need some adjustment.

To move an area skewed in space, you'll need to select all the vertices and move them simultaneously. In situationswhere you have multiple adjacent areas, moving the vertices (and keeping areas planar) may simply not be possible,and you may need to delete the area and redraw it.

Ways to Modify Areas:

1. Move an Area (in X, Y, or Z)

With an area selected, the Modify tab of Project Manager allows you to change the location of the entire area eitherin a global direction, or for skewed areas you can also move the area in a local direction.

2. Edit Vertices

You can select vertices of an area to contort or reposition them within the plane of the area. The Modify tab allowsyou to edit the coordinates. You need to Filter On the area vertices, and may need to Filter Off the nodes, to enablevertex selection and editing.

3. Insert a Vertex (Change the Shape)

You can insert additional vertices one at a time. Select an area edge and choose Split Boundary from the ModelView's context menu. A vertex will be inserted along the area edge which you can edit to change the shape of the area.

4. Delete the Area and Redraw it!

You may, in some instances, need to delete the area and re-create it, though this action will force you to redefine allthe loads on the area.

Defining Holes & Corridors

Holes are sub-areas within other areas that do not receive loads. Corridors are sub-areas that can receive higher loads,such as for IBC / ASCE 7 load requirements. You may define these items by sketching areas within an existing area. Ifyou draw such an area you will receive a prompt that allows you to choose which type of area you are creating.

Automatic Meshed Plates

Areas have no stiffness, so to represent a floor or wall you might use plate elements. This can be done by simplychecking a box on the Area and defining the plate thickness and material. Areas are meshed in the background, it maytake a minute or so for changes to appear in your model.

A mesh of plate elements may be generated from the definition of an area and any holes it may contain. Existing nodesand members within the plane of the area are incorporated into the plate mesh that you generate. If you have manuallycreated any plate elements within the area, then auto-meshing will not work.

Automatically meshes are managed by the system so that you can easily re-mesh areas with different settings and toaccommodate other model changes (like member elements passing through areas).

Convert Auto-mesh to Plates

You may convert the plate elements into manual plates, using Structure | Convert to Plates should you wish to takecontrol of the mesh, but then you will lose automatic management features.

Controlling Plate-Mesh Count



The total number of meshed-plates created for a model, is loosely controlled by the Auto. Mesh Factor in the ProjectSettings (Section 2.2). Increasing this number will cause more plates to be generated. The number of platesgenerated for an area is system-controlled, and is a function of the size of the area, the total number of areas in theproject, the number of boundary or 'constraint' points within the area and the setting in Project Settings. The moreareas and other elements you have in a model, the less impact the Auto-Mesh Factor will have, more plates will berequired for connectivity and alignment reasons.

New! You may also request a specific Element Count on each area (using the Override Count option) to have morecontrol over how plate meshes are refined. Strategic generation of plates cna improve your performance and also giveyou more accurate results. See plate meshing (Section 2.5) information for more details about convergence.


Area Side Support

The edges or sides of meshed Areas may be supported similar to nodes. Side supports are defined by selecting one ofthe Area sides in the Model View and selecting from the available constraints in the Support heading found on theModify Tab of the Project Manager. (Note: Area sides are not visible or selectable on areas that are not meshed.)

Side supports simply support all meshed nodes along that boundary. These are automatically updated if the area isremeshed. The ability to defining side support conditions for Areas is critical to obtaining accurate Area Results for aparticular model configuration.

Splitting Area Sides

You may split the side of an area, which inserts a new vertex at its mid-point. Right-click on the side and chooseYoucan then move this vertex along the edge to change the relative side lengths. Splitting area sides, or modifying areavertices may require you to redefine your edge supports.


Area Results

Areas are not true model objects (lacking stiffness) and as such have no results; however, if the Automatic MeshedPlates feature is selected, Areas are assigned stiffness properties and have self weight based on the selected materialand can also have edge or boundary results.

With unmeshed Areas you can report basic information about your area definitions for documentation purposes and tohelp you validate area loads and the generated results (and nodal and element forces created by them).

With Automatic Meshed Plates enabled, plates results are available, and results can be viewed the as they are withmanual Plate Elements (Section 2.5).

Area Side Results

Area Side Results are a summary of plate forces applied to nodes along that edge. These are very useful fordesigning shear walls and diaphragms when total or average results are easier to work with than individual plateelement results.

Results are available as Average, Detailed, or Total forces calculated for each Area side. In-plane Shear (V) andOverturning Moment (Mot) (Resultant only) are parallel to the edge, In-plane Axial (P) is perpendicular to theedge, Out-of-Plane Shear (V'), Out-of-Plane Moment (M'), .

Local axes and sign convention depend on the direction that Areas were drawn. Coordinates defining the Area sideresults are reported under the Side Direction/Ends heading.

2.8 Limitations

VisualAnalysis Philosophy



VisualAnalysis was created for engineers, like you, who want to focus on engineering, not fighting or decipheringsoftware. IES engineers have crafted this tool with these goals in mind:

Just enough features, avoiding software "bloat" that makes it cumbersomeFollow Microsoft usability guidelines for immediate productivityUse everyday engineering terms rather than software jargonMake common things trivially easy, other things are possibleError messages are polite and informative, offering solutions where possibleBuilt-in error prevention and validation to promote correct results

Limitations

VisualAnalysis handles what most engineers need, and what IES customers have requested. There are limitations inVisualAnalysis! If you need these (or other) features, please let us know...

Not an ANSYS or NASTRAN; VisualAnalysis is practical and down-to-earth friendly!Not useful for large displacements (geometric nonlinearity, except the cable element)No plastic analysis (you could manually iterate with increasing loads, inserting end releases to simulate)Not a 'turn-key' system for building or truss design. You decide the layout and must pick initial member sizesNo automatic total structural optimizationDoes not run inside or integrated with AutoCAD (or any other CAD tool)No internal pipe pressures.No orthotropic or anisotropic materials (linear, elastic isotropic only)No solid elements, or brick elementsNo curved beams (you may simulate through 'chords')No staged loading, or active or inactive elements acting per load caseNo pre-stressed or post-tensioned concrete design.No AASHTO bridge design

2.9 Soil-Spring GeneratorThe Soil Spring Generator is a fast and easy way to provide soil-support under a manual plate mesh. The generator willcreate compression-only springs with stiffnesses based on plate area and soil subgrade modulus. This is the typicalapproach to modeling support from a soil under a slab, footing, or grade beam.

To use this tool, select the plate elements to be supported and then choose the Structure | Soil Spring Generatorcommand.

Features

Speeds model creation when soil-bearing supports are modeled.Automatic stiffness calculation based on plate surface area.Spring supports are automatically applied perpendicular to selected plates.One-way action for springs is automatically set.

Limitations

Plate elements should all have the same local-z orientationOnly generates spring supports under manual plate elementsDoes not work with auto-meshed plates (their areas may change)Does not work with member elements.Spring supports do not update automatically if you later change plate dimensions.



There is no way to modify after generation: delete and re-create.

Operation

Selecting Plates

After choosing the Generate Soil Springs from Structure tab in the ribbon, you are asked to select plate elements tobe supported. Normally you will pre-select the plate elements to support before choosing this tool, but if you forget,you may select the plates before proceeding.

The elements need not lie in the same plane. When spring supports are created they will be perpendicular to the platesselected. If plates connected to a common node lie in the same plane, the spring stiffness for the adjacent plates will becombined into a single spring support.

Defining Soil Stiffness

You define the subgrade modulus using a value representative of the soil. Many soil mechanics texts list typicalsubgrade modulus values. The spring stiffness generated is calculated using the following formula:

KSpring = Subgrade Modulus * Plate Surface Area.

The total spring stiffness, K, is distributed to the three or four plate element nodes based on a tributary area methodusing the plate's geometry.

Determine Support Direction

The radio button for specifying the plate contact face (in local plate coordinates) is used so that the spring direction canbe set up consistently and correctly with a compression-only one-way action. For more information on the plate's localcoordinate system, see the VisualAnalysis User's Guide or on-line help. You may display plate local coordinatesgraphically in a Model Window.

Spring Superposition

If you already have springs attached to nodes of selected plates, you may replace them or superimpose the additionalstiffness into them.

2.10 Semi-Rigid ConnectionsRequires: Advanced Level

Introduction

You may optionally specify semi-rigid behavior for strong bending (Rz) and/or weak bending (Ry) at the ends of amember element. The other degrees of freedom (Dx, Dy, Dz, Rx) are always controlled by member end releases, so willbe either fully rigid or fully released.

Many typical steel connections are really not completely rigid or completely free (or pinned), but are semi-rigid to somedegree. These include the single web angle, double web angle, top and seat angles with double web angles, end plate,T-stub, and header plate connections. The semi-rigid connection feature of VisualAnalysis allows these connections tobe modeled with their various moment-theta curve shapes (rigidities).

This feature can have performance implications as you analyze. The analysis requires inverting a nonsymmetrical12x12 matrix for each connection.

Using Semi-Rigid Connections

VisualAnalysis has three different ways for modeling a semi-rigid connection: constant rigidity connections, bilinearrigidity connections, and three parameter power models.



The constant rigidity model only takes the connection rigidity value, Ri (linear moment rotation curve). The bilinearmoment rotation curve model takes two rigidity values and a moment value. The moment value is used to specifywhen the second rigidity value kicks in. Lastly, the three parameter power model is essentially a modified exponentialmodel. This model takes three parameters; n, Ri, and Mu. The parameter n is the shape factor or power index. Thelarger the value of n, the steeper the curve and the closer it "fits" the two tangents. Ri is the initial stiffness of theconnection. Mu represents the maximum moment and determines where the horizontal asymptote is that the curve willcome up to.

Three parameter power model curve.

How do I specify a semi-rigid end?

To specify a semi-rigid connection, select a member and open the Semi-Rigid characteristics located under the Modifytab.

How do I know what rigidity value to use for my connection?

This can be somewhat difficult to determine. There are a number of texts that address semi-rigid behavior. Forexample, Stability Design of Semi-Rigid Frames by Chen, et al. gives formulas and tables for specific connections andtheir associated rigidity values. See the reference section for more information about semi-rigid connections.

Could this be used to model a plastic hinge?

Yes, both the bilinear rigidity and three parameter power models facilitate a "limit" moment value. This could bespecified as the plastic moment allowing for an approximate model of hinging behavior.

Note that members would have to be split and/or tweaked further to account for hinge behavior not occurring at thecolumn connections. So while it works, it would still be a manually iterative analysis to determine hinge locations andsplit and insert them. And the locations would be different for each load case or combination! So it is not a verypractical plastic-analysis for any non-trivial frame or set of load cases.

Nonlinear Analysis

The rigidity model selected for semi-rigid behavior of the connection will designate whether a linear or a nonlinearanalysis (Section 4.3) is performed. The constant rigidity model uses a linear analysis. The bilinear rigidity and thethree parameter power model both require a nonlinear analysis.

Reporting Semi-Rigid Connections

Member Semi-Rigid Connections is the only report item available. For each specified semi-rigid connection this reportspecifies:

The member and node it is applied to - this is just the member and node name respectively.



The Semi-Rigid connection model type - this can be constant stiffness, bilinear stiffness, or the 3 parameterpower model.The direction - this is the degree of freedom specified as semi-rigid.Stiffness 1 - this is the stiffness for the constant rigidity model, the first stiffness for the bilinear model, andthe initial rigidity for the 3 parameter power model.Stiffness 2 - this is the second stiffness for the bilinear model and is not used in the other two models.Moment - For the bilinear model, this is the transition moment, for the 3 parameter power model this is theultimate moment. Power - This displays the shape factor for the 3 parameter power model. For either of the other two modelsit will display -NA-.

References

Stability Design of Semi-Rigid Frames by W.F. Chen, Yoshiaki Goto, and J.Y. Richard Liew. John Wiley & Sons, Inc. Copyright 1996 ISBN 0-471-07670-8.

Modeling of Connections in the Analyses of Thin-Walled Space Frames by H. Shakourzadeh, Y.Q. Guo, and J.L. Batoz. Computers and Structures 71, 423-433, Copyright 1999.



3 Load

3.1 Loading Topics

Introduction

Loading forms the second step in any structural analysis. After you have constructed a model of the structure you alsomodel the forces or events the structure must withstand. These include things like the weight of the structure itself, theloads from occupants and earthquakes, snow, and wind. While VisualAnalysis does not automatically calculate therequired load values (in most cases) or automatically generate those loads, it does provide tools to make loadapplication easy.

Self-weight

Self-weight of the model (weight of members and plates actually modeled) is automatically included, by default,through the "Dead Loads". Otherwise any Service Load Case with a load source of Dead loads or Seismic loads mayincorporate self-weight. Self-weight may be applied in any direction and scaled to accommodate different needs. If self-weight is included in more than one load case, careful attention to load combinations needs to be taken to ensureduplicate self-weight is not being included. Self-weight is automatically factored in load combinations. Caution:VisualAnalysis cannot include any self-weight for items that are NOT part of your model!

Loading Topics

Load Cases (Section 3.6): What they are and how to use them. Load Case ManagerNodal Loads (Section 3.2)Member Loads (Section 3.3)Plate Loads (Section 3.5)Area Loads (Section 3.4)Cable Loads? Nope. Split them and apply nodal loads.Dynamic Loads (Section 3.7): Nodal mass, dynamic responseWorking with Loads (Section 9.6): Apply, Find, Edit, Copy, Scale, DeleteResponse Spectrum Generator (Section 3.7): Create design spectra per IBC

Advanced Loading

Moving Loads (Section 3.8): Trains, cranes, and automobiles.Time History Loads (Section 4.7): Forcing functions, seismic events, harmonic loadingPatterned Load Cases (Section 3.6): Combine loads differently based on patternsLive Load Reduction (Section 3.6): Load combinations using reduced live loads

3.2 Nodal Loads

Nodal Forces or Moments

Forces and moments in some structure types may be applied directly to nodes in the model that are not supported inthe same direction. Nodal loads are always applied parallel to a global coordinate {X, Y, or Z}, using the sign on themagnitude to place the load in the opposite direction.

Skewed Direction?

If skewed loads are to be applied, two or three component loadings should be used to achieve the effect. VisualAnalysisdoes not offer angled, eccentric, or skew options.



Support Settlements

A settlement is a specified displacement or rotation at a supported node. You can apply settlements just like you wouldapply other nodal loads. Select the node first and define the settlement direction and distance. The node must besupported in the direction of the settlement.

Nodal Mass

You can specify a lumped mass on a Node, which is then used for inertia during dynamic analysis. This mass is not usedin self-weight, static analysis, or in any other way.

3.3 Member Loads

Load Types

The following types of member forces or moment loads are possible, depending on the structure type:

Concentrated (point forces or moments)Uniform (full span or partial span)Linear (full span or partial span, triangular or trapezoidal)Thermal (temperature change--axial effect, or gradient--bending effect)Wind+Ice

Loads may be applied in either a local direction or a global direction. Distributed global loads may be applied to theprojected length of a member, as is typical for applying snow loads to a sloped roof. The sign of the magnitude can beused to reverse the action of the load, e.g., from "up" to "down". If your local-direction loads are going in the wrongdirection on some members, you can use the Structure | Reverse Local Axes command to insure your members areall aligned in the same direction.

Load Directions

The choice of directions depends on the structure type and the load type. In general, loads may be applied with respectto the global coordinate system or with respect to each member's own local coordinate system. Member loads arealways assumed to pass through the centroid (or shear center) of the member.

Working with the local system is usually preferred, as it is much easier to be certain of the direction and type of load.

With global loads, the actual effect on the member depends on the orientation of the member. For example, aconcentrated force in the global X direction might act on a beam as an axial load, while the same load applied to acolumn could be a transverse force. Directions are shown with coordinate letters (X, Y, or Z for global coordinates andx, y, or z for local coordinates) and labeled as a shear force, axial force, or moment.

Use a negative magnitude to apply a load in the opposite direction. For example, a negative axial force might indicatecompression while a positive force means tension. For the other directions, a negative value means the load actsopposite to the coordinate system direction. For rotation, a positive load follows the right-hand-rule, meaning that acounter-clockwise rotation occurs on an axis that is pointed toward you.

Global distributed loads may be applied directly on the member or they may be distributed over the projected length ofthe member. The total value of the load is reduced if it is over a shorter projected length.

Load Offsets

Member loads are located from the starting node of the member using an offset along the length. This is defined bynode 1, or more simply, by the direction in which the member was sketched. For distributed loads, both the startingoffset and the ending offset are measured from the starting node. A full span load has a starting offset of zero and anending offset of L, the span length.

Multiple distributed loads may be applied on a member, but for display purposes they may not overlap.



Generating Multiple Member Point Loads

VisualAnalysis has a feature for rapidly generating multiple point loads across members.Select either Fractional SpanPoints or Evenly Spaced Points to generate multiple concentrated loads on each member. Fractional loads may beplaced randomly; they also work well for placing loads at say 1/3 points of members with different span lengths. Usethe evenly spaced option to create loads a fixed distance apart.

Although the multiple point loads are generated in a single step, they immediately become independent concentratedloads for editing or deleting.

Eccentric Member Loads?

There is no built-in facility for defining an eccentric load on a member in VisualAnalysis. All member loads pass throughthe centroid (or shear center) and cause no secondary effects. For eccentric loads that cause an additional moment,then modifying the model or applying both the load and the associated moment manually can account for theeccentricity.

Wind + Ice Loads on Members

For open truss and frames you may wish to apply wind pressure directly to members. VisualAnalysis can calculatethe pressure magnitude per ASCE 7 requirements, but you must manually apply the load to each member. You mayalso calculate pressure values yourself. The pressure is a function of the load parameters, as specified below and alsothings like wind speed, as specified in the Service Load Case (Section 3.6).

The surface area used for wind pressures is the length of the member multiplied by the member shape 'size', this areais reduced as the orientation of the member becomes closer to parallel to the wind direction. The 'size' of the member isconservatively assumed to be the diameter of the smallest circle that would contain the shape cross-section, regardlessof the direction of the wind.

The ASCE 7 approach to wind pressure is this: Pressure = q(z)*G*Cf, where q(z) is from Equation 29.3 in ASCE 7-10.Where q(z) = 0.00256*Kz*Kzt*Kd*V2, and we use the average height (z) of the member element for the uniform loadpressure. G is the gust factor. Both ice and wind loads are applied as constant uniform loads over the length of themember. For more fine-grained control of member wind pressures you could split member elements into multiplepieces.

We use a Cf from the ASCE Publication 113 Substation Structure Design Guide, p. 40-41 and varies between 0.54 and2.0 depending on the shape and length of the member. You may also override Cf to use values from ASCE 7-05 forvarious types of structures. A conservative value for Cf is 2.0.

ShapeType Aspect Ratio CfRectangular or Square Any 2.0

Round or Pipe Any 0.6

Other Shapes L/d > 40.0 (long members) 1.6

L/d > 8.0 1.28

L/d > 4.0 1.12

L/d < 4.0 (short members) 0.96

Because ice build-up on members can dramatically affect the surface area for wind loads on members, you maydefine ice thickness for the wind pressure calculation. If you use ASCE 7 wind loads, the ice thickness is also adjustedby your Service Load Case (Section 3.6) settings and the input thickness is treated as a nominal thickness that isadjusted over the height of the model. Ice loads are always applied in the same direction as self-weight, using thevertical direction specified in the Project Settings.

The ice value entered for a wind load is used ONLY to increase the surface area--you should apply the



ice weight in a separate load case to account for the actual weight of the ice.

3.4 Area LoadsOne of the primary reasons for using areas is to create loads that are independent of your actual model and are tosimplify load application as area loads are automatically distributed to model elements based on tributary areas andspan directions. The area allows you to define the load-span direction as either one-way (e.g. metal deck) or two-way(e.g. concrete slab). To load an area, select it in the Model View, Right-Click to find the Apply Area Load command.See Static Loads for more details about area load options.

Area Loads apply only to objects that lie within the boundary and plane of an area. There is no such thing as an area"offset". Loads will not project onto members or plates that are not in the plane. If you move your model out-from-under an area, then the loads may not get applied to anything at all.

Area Loads on Plates

When area loads are applied to plates, the pressures are transmitted directly to plate elements within the plane andconfines of the area. If there are holes in the plate mesh, then no load will be applied over this portion of the mesh--loads are not 'distributed' to nearby plates. If your area load extends beyond the plate element mesh, or is completelywithin a single plate element (but not completely over that plate), then you may not get the loads you expect! Pleasealso review plate loads (Section 3.5) for other issues to be aware of.

Tributary Area Loads on Members

Area loads on members span according to the span-direction (Section 2.7) specified on the area itself. A one-wayspan distribution can be specified (as would be used for a metal deck) or a two-way distribution may be used. You mayhave a model with both primary and secondary members (e.g. bracing) To prevent secondary members from receivingthe area loads (direct loads from floors, snow, wind, etc.) set the member's Framing type (Section 2.4).

Tributary area loads applied to members are generated numerically through numerical-integration, which is anapproximation. The accuracy will be a function of the size of your area, the arrangement of members in theplane, and the Performance vs. Accuracy settings in the project. It is possible to apply a one-way area loadthat spans to 'nothing'!

VisualAnalysis offers an Area Loads: Generated Loads filter option, and a report table that can help you validate theactual loads that were applied to members for analysis. Applied load magnitudes may not be perfectly uniform or lineardue to approximations, geometry, and numerical round-off. You should compare the total generated loads (orreactions) with your total applied area loads to confirm they are accurate. If you have issues, using smaller-sized,or fewer-sided areas (e.g. quadrilaterals and rectangles) might improve the load values.

ASCE 7 Snow Loads

IES has not (yet) specifically implemented snow load support, but by using area loads you can accomplish what youneed to do. Each area can only accept a single uniform or linear varying load in each load case, so there is no direct orbuilt-in way to accomplish "drift zones" or unbalanced loading. You can accomplish this in at least two different ways:

1. Use multiple areas on a roof system so that you can apply different kinds of loads to different areas.2. Use a combination of area loads and loads applied directly to members or nodes.

ASCE 7 Seismic Loads?

IES has not implemented any direct way to handle seismic loads using area loads. Generally you will want to use directapplication of member, plate, or nodal loads, or you may use Rigid Diaphragm Loads to accomplish static-equivalent



loading for seismic analysis.

ASCE 7 Wind Loads on Areas

VisualAnalysis implements a wind-load generator that can help with ASCE 7 load application, following the DirectionalProcedure (Wind Loads on Building- MWFRS) in chapter 27 of the specification, for Enclosed or Partially Enclosedbuildings. Open structures are not supported for Area Loads, you may be able to use member loads for openstructures. The system is designed to give you the power to apply wind loads, but not to automate anything beyond theactual pressure calculation. About 20 input parameters are required, along with a good understanding of ASCE 7 windprovisions.

Steps to Create Wind Loads:

1. Define project-wide data for wind loads in the Project Settings (Section 2.2) Tab of Project Manager.2. Create Areas (Section 2.7) to represent the places where you would like to apply a wind load pressure. Each

area can accept one wind load pressure, in each load case. Additional loads may be placed directly on nodes,members, or plates, if the area loads are insufficient for your needs. It is a good idea to define all your areas sothat their "normal direction" (perpendicular) is consistently outward to the building! Knowing the "outward" and"inward" directions for areas is critical to getting wind loads applied properly.

3. Set up case-specific data in each wind load service case (Section 3.6) that you need to use. (Note: emptyservice cases are hidden by default in Load Case Manager, you can display them with a check-box at the bottomof the list.)

4. Apply wind loads to areas, in each directional wind-load service case; each load offers a number of possiblechoices for the type of pressure to use.

The real “trick” to our system is the creation of Areas. This is a manual process and you can use single areas over anentire face of a structure, or you can create multiple areas to represent the different types of wind loads that ASCE 7requires. You can place holes in your areas (by drawing an area within an area). Areas do NOT need to be created withnodes to represent their shape, you can use an Edit Grid to place Area vertices anywhere, and they will have the effectof loading any members (or plates) that lie within their plane.

We have deliberately not automated the whole process because we don’t think it is rational or even possible for us todo it correctly. We are trying to provide a tool that you can use in the way you see fit. If you find it easier to determinethe wind pressures outside of our tool, you can still do so (but we would like to know why, so we can improve it!)

Area Side Loads Requires: Advanced LevelA uniform loading can be applied to area sides (in any direction, including in the plane of the area) by entering aresultant magnitude of the load. The loading is distributed to the nodes along that edge (both manually created nodesand nodes from auto-meshing).

3.5 Plate LoadsArea loads may be more convenient than plate loads because they can be modified independently of the platesthemselves and won't get deleted if you remove the plate elements from your model to re-configure the layout.

Plate Load Types

Plate loads may be applied individually to plates or across a plate mesh. All plate loads act perpendicular to the plateelement to cause bending, except for 'Change in Temperature' loads which are in-plane. Positive magnitude loads act inthe +z local direction while negative loads act in the -z direction. If loads are being applied in the wrong direction onsome plates, the Structure | Reverse Local Axes command can be used to ensure your plate elements are allaligned in the same direction.

Plate element loads are applied as "equivalent nodal loads", which means that you cannot get any plate bending out ofa single plate element! You MUST use a plate mesh to get accurate plate behavior.



Uniform Pressure:a pressure applied uniformly across a plate elementLinear Pressure: a unique pressure is applied to each corner of the plate (it may be linear or 'warped')Hydrostatic (mesh): results in a linear pressure based on a global fluid level, note the pressure on someelements above the datum may be zero!Linear ( mesh): just like hydrostatic, but pressures on plates 'above the datum' will just change sign theywon't go to zero.Change in temperature: causes plates to expand or contract in the plane, just a dT magnitude.Gradient temperature: Specified as dT/unit-thickness, will cause contraction on one face, expansion on theother to cause bending.

Across Mesh Loads

When applying linear or hydrostatic loads across a plate mesh the definition of the load depends upon globalcoordinates and directions. The linear variation must be parallel to one of the three global axes. Be careful! Definedloads that do not vary across your plates or loads that end up being zero on the plates can be created. Use Tools| Model Check or the Find tool to help locate any problems.

Once loads are created for the "mesh," the loads are independently acting, selectable and editable. Theymay be modified or deleted separately, but their definitions still depend upon the global coordinate locations specified.This means that if plate elements are moved in the model, the magnitude of the loads will change accordingly andcould become zero or change direction! All the loads in the group may be selected to edit them; however there is noautomatic-selection for just this set of loads.

Hydrostatic loads are a special case of the linear mesh loads, and are unique in that above the fluid datum the load isalways zero. With a linear load on the other hand, if it crosses the 'zero' mark, the load changes direction and increasesin magnitude as the distance from this line increases.

Apply Concentrated Loads on Plates?

VisualAnalysis does not directly support concentrated plate element loads. Generally a plate will be modeled as a platemesh and concentrated loads can be applied to the nearest node. The nodes can even be moved (distorting theneighboring plate elements) to position the load in the correct location.

Apply Edge Loads on Plates?

VisualAnalysis does not directly support loads on plate edges, either in-plane or out-of-plane. You could manuallyapply nodal loads along the edge.

In some situations, a member element may be used along the edge of a plate mesh, for loading purposes. Justremember that members and plates are only connected at common nodes.

You may also use Areas (Section 2.7) and Area Loads (Section 3.4) to apply loads to the edge of a plate mesh.

3.6 Load Cases and Combinations

Load Case and Combination Types

Case Type DescriptionService LoadCase

A container for holding physical loads, usually grouped by load source. May also include self-weight of the model. These cases may be analyzed or not, and may be 'patterned' for live loads(advanced). For wind loads there are settings specific to ASCE7 that you may use in conjunctionwith area loads. These are not used directly for design checks (Section 9.1.2).

EquationCombination

A way of combining service cases, with load factors based on load sources. These are used forBuilding Code combinations, and you can create your own custom combinations as well. Thesecan be used for design checks (Section 9.1.2).



FactoredCombination

A way of combining service cases with arbitrary load factors. These are good for patternedloading and other custom load combinations where you are picking & choosing the cases andfactors. These can be used for design checks (Section 9.1.2).

DynamicResponseCase

A way of specifying a seismic event along with direction factors. Dynamic response case resultsare computed by combining results from mode shapes. No design checks directly -- use asuperposition combination.


AdvancedCases

Description

Time HistoryCase

A load case that applies a 'forcing function' load that varies with time. No design checksdirectly -- use a superposition combination.

Moving LoadCase (Section3.8)

A load case for applying simple moving loads (a truck and/or patterned uniform) along a singlebeam-line. Moving loads produce envelope results and are handled independently of other loadcases during analysis. No design checks directly -- use a superposition combination.

ResultSuperpositionCombination(Section 4.8)

This is a post-analysis load combination. These are used to combine time-history results,dynamic response results, and moving load results with normal static results. Note that theseload combinations are really just an "envelope" with extreme+ and extremevalues.Superposition combinations may not be accurate in the presence of nonlinear features! Designchecks may be performed on superposition combinations if you mark them for design (ASDor LRFD or Deflection)

Service Load Cases

Service cases are used to organize the physical loads on a model, with an eye toward load combinations used for designchecks. VisualAnalysis supports many different load types to represent physical loads on your model such asconcentrated nodal loads, distributed member loads, etc. These physical or actual loads are grouped inside a containercalled a Service Load Case.

Each Service Load Case has a load source associated with it. The source defines the physical origin of the loading.Common load sources include dead load, live load, and wind load. Load sources are used to make load combinationseasier. They are described in more detail below.

Most design codes require that you check various combinations of loads. The LRFD specification for steel, the ACIspecification for concrete, and the IBC specification for buildings define combinations using equations like 1.2D + 1.6L.In these combinations, loads are grouped according to their sources and given factors to account for the relativeuncertainties. In many cases it is important, as a designer, to look at other loading configurations that may also takeplace. One such technique is called patterned loading. VisualAnalysis supports these operations through load cases.

What are Load Sources?

VisualAnalysis provides convenient ways to both organize and combine your loads. Each Service Load Case can bedefined as coming from a particular load source. These load sources are derived from the most common designspecifications in the USA such as those produced by organizations such as ASCE, IBC, and AASHTO. There is apreference setting under Tools | Preferences, Project to specify which service load cases are set up when you starta new project. The default is to generate load cases for ASCE 7 sources only. You may manually create service loadcases with any names you desire, without much regard to the "load source" definition.

The existence of a load source type in the software does not mean that a corresponding physical load is supported. Forexample, there is no "creep" load source available in VisualAnalysis that you use for loads on a concrete frame.

Case Type Description



However, you can still create member loads and place them in a load case to represent the effects of creep on yourstructure.

Load sources are used in VisualAnalysis to create Equation Combination load combinations and (automated) BuildingCode combinations. These load combinations allow you to combine groups of service loads together, whileautomatically applying the appropriate multiplication factors based on the source type. VisualAnalysis can also generatethe set of factored combinations needed for working with LRFD, IBC, or ACI codes. The support is not entirely foolproofhowever as careful attention is needed for patterned loading situations and other possible complications. For moreinformation refer to the Loading section.

Load sources are not customizable in VisualAnalysis. However, you may create any number of service load caseswith arbitrary names and use them for whatever you like and create custom factored load combinations. The existenceof a load source in VisualAnalysis does not imply that there are specific loads or calculations done in the software--theseare just ways of organizing and combining your loads.

Simple Load Sources

Load Source AbbreviationDead D

Live L

Seismic (directional) E+X, E-X, ...

Wind loads(directional) W+X, W-X, ...

ASCE 7 Load Sources

LoadSource

IBC /ASCE 7

Explanation

Dead D Structure self-weight or permanent fixtures on or in the structure.

Ice Weight Di Weight of ice.

Live L Loads due to moveable equipment or occupancy. Live loads may be "patterned" inthe advanced level, and if so are denoted with L1, L2, L3, etc. with a pattern ID.Caution: Live loads are reduced by 50% in some IBC load combinations, use Lpasource for loads > 100 psf.

Live(PublicAssembly)

Lpa(>100psf) Garage loads, Public Assembly areas, or loads greater than 100psf. They have alsobeen called "Exception" loads, because they appear in a separate clause in somebuilding codes.

Roof Live Lr Live loads on a roof.

Rain or Ice R Initial rainwater or ice exclusive of ponding contributions.

Snow S Snow loads. Notes: There is no separation in VisualAnalysis for non-shedding loads.There is no load 'source' for unbalanced snow loading, which should be handled like'patterned loading' using multiple snow load cases and load combinations.

Seismic(directional)

E+X, E-X,E+Y,E-Y,E+Z, E-Z

Earthquake or Seismic loads. EX is for seismic loads in the positive global X direction,E-X is in for the negative global X direction, and similarly for the Y and Z directions.

Seismic E Earthquake or seismic loads to include with each of the directional seismic loads.(You should rarely need to use this, it is provided primarily for backwardcompatibility and ultimate flexibility!)

Earth H Loads due to differential settlement, backfill on a wall, etc.



Pressure Caution: Combinations do not distinguish the difference between H adds or resiststhe primary load variable in an equation. It is up to you to handle the loadcombinations for special circumstances with earth loading.

Fluids F Water in a tank.

Flood Fa The river flowing over your bridge or through your building.

Temperature T Thermal loads. IBC calls these self-straining loads.

Wind loads(directional)

W+X, W-X,W+Y, W-Y,W+Z, W-Z,and more!

Wind pressure loads. As in the seismic loads above, using just W will apply the sameload in all directions. WX is for wind loads in the positive X direction, W-X is for windloads in the negative X direction, and similarly for the Y and Z directions.

Optional "Skewed" wind load directions are available (+X+Y, -X+Y, +X-Y, etc.),enable these using Tools | Preferences, Project and use them for your owncustom load cases and combinations, but they are primarily here for backwardcompatibility

Wind on Ice WiX, Wi-X,... Wind on Ice. Ice will increase the surface-area of members and therefore the windforces.

Other loads U User-defined source available for special loads that you want to factorindependently of other sources. These are not used in Building Code Combinations.

Load Case Manager

The load case manager is accessed by selecting Loading | Load Case Manager. Essentially the load case manager isa convenient place to view and manage all load cases and load combinations. The only exception to this is theadvanced-level Project Envelope (Section 4.9), which acts similar to a load case but is really just a 'result case'.

Load Case Manager is where you go to setup 'design load cases'. Load cases for design are either load combinations orsuperposition results. You may specify load cases to be checked for strength (ASD or LRFD) or deflections. See moreabout design checks (Section 9.1.2).

Service Load Cases

Service load cases are containers for real loads. Typical service load cases are automatically created with a new project,but more can always be added by going to Loading | Load Case Manager and clicking on the Service Cases tab. Theweight of a piece of machinery, the pressure of the wind, and the settlement of a support are all real, static loads thatmay be included in a service load case. All static loads must reside in a service load case. Generally it is best to separateloads into easily managed groups based on load sources or some other preferred organization.

Self Weight

Self-weight is automatically included in the Dead Load service case, in the vertical direction. The self-weight of themodel itself is automatically calculated based on member, plate, and cable element properties, but can, if necessary bescaled or factored using the load case settings. Seismic load cases may also include the effect of self-weight, factoredinto a horizontal direction.

Patterned Live Load CasesRequires: Advanced LevelLive load service cases may be given a pattern ID (a positive integer) to help you easily model various loading patterns,such as odd/even span loads. Each patterned service load case is combined independently in building code loadcombinations from other patterned load cases. For example, you can place odd-span loads in a "Pattern 1" service case

LoadSource

IBC /ASCE 7

Explanation



and even-span loads in a "Pattern 2" case and the building code combination will generate something like:

1.2D + 1.6L1 + 1.6L1.2D + 1.6L2 + 1.6L

Note how any loads in an non-patterned live load case are included in both combinations.

If you have the advanced level of VisualAnalysis three patterned service cases are automatically generated andavailable for your immediate use: L1, L2, L3, but you may manually create as many different patterned service loadcases as you need.

There are other ways to create load patterns in VisualAnalysis, for example: using custom factored load combinationswith various load factors--which would not require the advanced level of the software!

ASCE 7 Wind Load Settings

Service load cases that have a wind load source may be used to help generate area loads (e.g. for building surfaces)or member loads (Section 3.3) (e.g. for open towers) based on ASCE 7 criteria.

Note that you must manually apply loads to members or areas. The system is not automatic--VisualAnalysis helpswith calculating pressures based on the input data.

The following case or project settings are defined by ASCE 7, but you will find 'tooltips' if you hover over the item inthe Service Case dialog box:

Per Wind Load Case

Exposure CategoryEnclosure CategoryProjected WidthSide LengthInternal PressureRoof PressureDirectionality Factor, KdTopographic Effects (with numerous options!)Large Volume ReductionAir Density Adjustments

Project-Wide Wind Settings

Ground ElevationMean Roof HeightWind Speed (mph)Gust Factor

ASCE 7 Seismic Settings

The Project Settings (Section 2.2) allow you to define seismic parameters that are currently ONLY used in thegeneration of IBC or ASCE 7 load combinations in the Building Code Combination system. These settings determine theEv +/- Eh portions of seismic loads and automatically include the vertical component as a function of your 'self weight'service loads "D". The system will use the rho factors and then also generate any required Overstrength loadcombinations. You will see the effects of this in the "Effective Equation" shown in the Load Case Manager, or loadcombination reports.

Building Code Combinations

Building code combinations from a variety of building codes are built-in to VisualAnalysis. When selected these



combinations are automatically maintained as loads are added or removed to service load cases. The desired buildingcode or codes to use are selected at the bottom of the Load Combinations tab of the Load Case Manager. Thissystem was designed for use with IBC or ASCE 7 load sources. If you are using the AASHTO load sources, you will needto manually generate (or import) your load combinations.

The building code combinations implemented in VisualAnalysis do not necessarily represent all possible loadcombinations or variations present in a particular building code. For example, in the implementation of ASCE 7-10load combinations, the major equations are implemented, but exceptions clauses of section 2.4 dealing with H, F, Faare not implemented directly. Similarly VisualAnalysis does not deal directly with T (self-straining) conditions at all--soyou may need to manually create custom load combinations to deal with special circumstances.

How it Works

When one of the building code combinations is selected, VisualAnalysis will use the current service load cases andgenerate the necessary combinations prescribed for that code. Note that any custom equation or factored combinationsthat are created manually will remain unaffected. When VisualAnalysis generates building code combinations, it willgenerate combinations including the effects of wind and seismic in various directions, including (+/-X, +/-Y, +/-Z). Onlyload cases that actually contain loads or self-weight are included in the combinations. The Load Case Manager will thendisplay the 'effective' combination of the equation which may be different than the equation in the building code.

Built-In Code Combinations

The following are hard-coded into VisualAnalysis 10.0, you generally only need to select one of these to get the loadcombinations you need. You might use both ASD and LRFD if you are doing some strength-level design and someservice-level design.

ASCE 7-10 both LRFD and ASDASCE 7-05 both LRFD and ASDIBC 2009 both LRFD and ASD

Taking Charge, Controlling Performance

The automatic system is fast, convenient, and comprehensive--but not very intelligent. You can end up with redundantload combinations, depending on the actual loads you have applied. One of the biggest drains on VisualAnalysisperformance is having extra load combinations to analyze, search, and report.

You can manually delete redundant load combinations--but they may get regenerated if you add or remove loads orservice load cases. You can convert all the combinations to manual combinations and take full control. Reducing thenumber of load combinations to analyze and report may dramatically improve VisualAnalysis performance.

A Customizable System!

The building code combination system is fully customizable You may manually add, remove, or disable sets of codeequations, or add, edit, or remove individual equations from the sets. There is a hyperlink on the Load Combinationstab of Load Case Manager that allows customization.

If you had custom combinations in VA 12.0 or prior, they are not available, you will need to re-enter them. Seethe Upgrade Guide (Section 7.2) for more.

Live Load ReductionRequires: Design LevelYou may specify one or more levels for reducing live loads. This feature takes any service cases with the source as LiveLoads and combines them at reduced levels using the building code combination feature. In effect you will generateadditional load combinations, one set for each level you enable. You can then associate a Design Group (Section5.1.1) with one of these levels to take advantage of the reduced demands.



Factored Load Combinations

When an equation load combination does not work, a Factored Load Combination should be used which lists all desiredload cases with a specified factor. One common use for this type of load combination is patterned loading. In this case,multiple load cases might have the same source, yet require different factors for each. Use the Create a FactoredLoad Combination button located in the Load Case Manager to create a new combination.

Sometimes you want to combine loads with different factors on cases with the same source. For example, two live loadcases may need to be included in the same combination, but a load factor of 1 on the first and 1.5 on the second isdesired. Factored load combinations are more flexible than the equation load combinations because factors can beexplicitly set to each load case regardless of source.

You can import custom factored load combinations through the Clipboard (Section 8.7) exchange.

Response Load Cases

To perform a dynamic response analysis you need to have at least one Response Load Case defined. A response casecontains direction multipliers and a design spectrum. Use Loading | Load Case Manager and click on the Dynamictab to create a Response Load Case.

The direction multipliers define the direction of the seismic event and also scale the magnitude. You might think ofthem as direction cosines. If you want to simulate an earthquake in the X direction use X=1, Y=Z=0. Similarly toindicate the direction in the XZ plane, 45 degrees off the X-axis, use X=Z=0.707 and Y-0. If the square root of the sumof the squares of the direction cosines adds up to a number other than 1.0, then this scale factor is also applied.

The design spectrum is a data set representing a seismic event. Building codes often provide design spectra to use, oryou may have more accurate local information from previous events. The data represents a time history ofdisplacements or accelerations. You can include your own custom data in the file (the default is 'Spectrum.txt' located inthe Customizable Data folder (Section 1.9)).

3.7 Dynamic Loads

Include Mass of Model

The mass of member and plate elements is automatically calculated and included in a dynamic analysis. Internally,these masses are distributed to the nodes. For more accurate dynamic modeling, consider splitting members and platesto get a better distribution of mass.

Apply Extra Nodal Mass

Additional mass in your model can be specified through using lumped nodal mass. Use the Modify tab in ProjectManager to edit nodes to define additional displacement mass or rotational mass at this location in the structure.

Nodal masses are entered weight units. It may be easier to apply extra mass as static loads that are included throughthe Mode Shape Case, where you can include all the loads from a specified service case as dynamic mass.

The self-weight of the model is included automatically in the dynamic analysis.

Use Static Loads for Additional Mass

One way to include additional mass on a model is to specify a single static load case in the Load Case Manager. Thismay be a Service Load Case or one of the factored load combinations. The direction gravity is acting must also bespecified. Only loads with a component in the gravity direction will be included in the mass calculation.

The self-weight of the model is included automatically in the dynamic analysis.

Use Response Spectra

A Response Spectrum Analysis determines the behavior of the structure when subjected to a specified ground



acceleration or displacement, e.g., an earthquake. The magnitude of the acceleration or displacement is a function oftime and is referred to as a Design Spectrum in VisualAnalysis. Building codes often prescribe a seismic DesignSpectrum. Include a Design Spectrum in a Response Load Case using Loading | New Response Case. The dynamicresponse load case associates a specific Response Spectrum with the analysis and provides for direction and scalingfactors to adjust how the data is used for each particular analysis.

You also need to define the method for combining mode shapes. The default (best) method is CQC, but SRSS is alsoavailable, and there is a damping factor that you may need to adjust--steel behaves differently than concrete, forexample.

Create a Custom Response Spectrum

The data for response spectra used in VisualAnalysis is stored in a text file called spectrum.txt (Section 1.9). Aspecific earthquake's ground motion or other historical seismic data can be added here as a custom response spectrum.VisualAnalysis includes a few predefined sets of data, and you can generate new data per IBC using the Loading |Generate Response Spectrum command.

3.8 Moving LoadsRequires: Advanced Level

Introduction

Capabilities

Moving Loads are an analysis feature to model truck loads on bridges or crane loads on girders. These loads can movealong the length of the members in either the positive x-direction or when marked as "reversible" in both directions.This tool eliminates the need to create multiple load cases to simulate moving loads and provides much more intelligentreporting capabilities. The tool also manages the application of lane loads for worst possible effects, applying partiallane loads over members according to AASHTO requirements.

The tool comes with two pre-defined truck loads, the HS 20 Short and HS 20 Long, as defined by AASHTO. You can alsocreate your own custom trucks and lane loads.

Limitations

VisualAnalysis does not provide full AASHTO support, or sophisticated bridge analysis tools, there are some significantlimitations. Moving Loads can only be applied to a contiguous chain of members. To load two different chains ofmembers with moving loads, you must create two Moving Load Cases. Only one truck is allowed per movingload case. Moving loads can only be applied to member elements in the Global Y-direction. There is no way to distributethe moving loads laterally to multiple member chains. Moving Loads cannot be applied directly to plate elements, butthey can be applied to members in a structure that contains plates.

To simulate multiple lanes, you could create some sort of model construct with a "fictitious" chain of members, whosejob is simply to distribute the moving load to "real" model elements. You could use rigid-link members to connect thetwo systems. If you separate the lanes into different load cases, then the loads are not kept in-synch with each other.

Due to the method used to calculate moving load results, superposition is used, moving loads are not allowed onnonlinear structures. This means that cable elements, semi-rigid connections, or tension-only (or compression-only)elements will prevent the application of moving loads on a structure. In these situations you will need to manuallyhandle moving loads with multiple load cases.

Results

Results for Moving Load Cases are presented in Extreme Min. and Extreme Max. envelope form.

When reporting results for moving load cases in a Report View, you can include the "When?" report column to indicatethe moving load position associated with the result in the column on its left. Include the "When?" column immediately



following a column with results, like Mz, or Vy.

The Moving Load results also offer Influence Diagrams for nodes or members at points you specify.

Design Checks

Moving Load Cases can also be combined with results from any other type of load case using Result SuperpositionCombinations (Section 4.8). This is the approach to take to get design checks for your moving load results.

Applying Moving Loads

Creating Moving Loads

Moving loads are applied by creating a Moving Load Case through the Load Case Manager, Advanced tab. Typically youwill want to select the members to load before you choose this command, as it is usually easier to select themgraphically.

Editing Moving Loads

Once you have created a Moving Load Case, you can modify the load that was generated by selecting it graphically inthe Model View, or through the Find Tool. The properties will appear in the Project Manager's Modify tab.

Creating New Trucks

New trucks you define are saved in the fileTruckLoad.xml normally located in the Data Files (Section 1.7) folder onyour machine. If you create a project with a custom truck load, the project file will be portable to other machines, eventhough the truck is not defined there. You may add modify or delete custom truck definitions, within the Moving LoadCase dialog box. Trucks may have multiple axels, and an optional associated lane load.

Analysis Options

The Moving Load feature works by creating and analyzing a series of "behind the scenes" load cases that place thetruck loads at incremental distances starting at one end of the member and moving across to the other end. Thenumber of points where the load is placed along each member is determined by the number of Load Stepping Pointsper Member. This number is specified by through the Advanced Analysis Options in the Project Settings. The optionis not available unless you have created a Moving Load Case in your project.

Increasing this number may yield more precise results, but will also increase the size of your project file, slow theperformance of the analysis, and increase the output in reports.

Note: A nonlinear model will preclude the use of moving loads because the analysis relies on superposition, which isinvalid for nonlinear models.

Influence Diagrams

How To Use

Once a Moving Load Case has been analyzed, Influence Diagrams can be plotted for members. They are plotted byselecting a member in a Moving Load Case Result view and either right clicking on it, and selecting Influence Diagramfrom the context menu. Influence diagrams are available for any node or member in the structure. For members, youspecify the result of interest, and the offset along the member.

The influence diagrams (by default) are plotted for dy, Mz, and Vy at the center of the selected member. The items toplot, as well as the member offset are changed using the Filter tab of the Project Manager.

Influence Refresher

Influence lines represent the effect of the moving load on a particular point in the model as the load moves. Influencediagrams are constructed for a positive (upward Global Y) 1 kip point load. The vertical axis shows the magnitude of the



result in question when the 1 kip load is applied, while the horizontal axis shows the position of the 1 kip load along themember chain. The typical use for these influence diagrams is to determine where to place other (perhaps non-moving)loads to achieve a maximum affect at some point in the structure. The moving load analysis does this automatically forthe moving truck load and lane loads, but you might have other loads that need to be positioned in another load case.

For a more complete discussion of influence diagrams you might consult any one of a dozen standard textbooks, suchas chapter 10 in "Structural Analysis" by Jeffrey P. Laible (ISBN 0-03-063382-6).

Reporting Moving Load Case Results

Report Tables

Moving Loads are reported in much the same way as any other member results. Report tables, such as Member InternalForces and Member Internal Stresses, work with moving load cases as well. There is also a table for reporting theMoving Loads you have defined.

Member Result Sections

One big difference you will notice when reporting moving load case results is that the "Number of member resultssections" value has no effect on the number of such sections reported for moving load case results. This differencearises as a result of the way in which moving load case results are calculated and stored. The results presented formoving load cases are "envelope" results. The Moving Load Tool works by creating and analyzing a series of load casesthat place the truck loads at incremental distances starting at one end of the member and moving across to the otherend.

The number of points reported for each member is determined by the number of Load Stepping Points per Member.Once the load has been placed at every point necessary, and the analysis has been run, VisualAnalysis searches to findthe maximum and minimum values for moment, shear, etc at each point. Then, it stores these values along with thelocation of the moving load when they occurred. Thus report tables cannot be shortened (interpolated) without losingthe location information.

Determining Load Location for a Result

To find where the truck was when a given moment or stress occurred in a member you will need to manually include a"When?" report column. When this column is included in a report, it displays the location of the moving load thatproduced the result in the column to it's left. To include this column, right-click on the report table, and choose TableProperties from the context menu. Then you can insert a "When?" column into the table.

It should be noted that the "When?" report column does not return anything if you are using a truck that consists ofonly a lane load. This occurs because the lane load, which is basically just a uniform load, is not applied in an easilyspecified position, but instead could be applied over various parts of the whole member chain to produce the worst caseresults.

3.9 Load HelperThis utility allows you to use predefined loads from ASCE 7 to apply loads to nodes, members, plates, or areas. Currently the load helper assists with dead loads and live loads. The definitions are saved in a UserLoads.xml file inthe IES data folder (Section 1.9), and as such will be available for future projects.

Creating Dead Load Definitions

You can use Loading | ASCE Load Helper command on the main menu, then use the Dead Loads tab. Various ASCE7 materials are listed and you can combine materials together and give them a name.

Creating Live Load Definitions

You can use Loading | ASCE Load Helper command on the main menu, then use the Live Loads tab.



Applying ASCE 7 Loads

When applying loads in a service case using either Dead or Live for the load source, you can use the ASCE 7 Load drop-down to pick the named load. For all loads you specify the force and direction as you normally would (with somerestrictions) and there is a check box to reverse the sign on the magnitude, which flips the direction 180 degrees.

With nodal loads you will need to specify tributary width and height, and the actual force is calculated for you. Youcannot use this definition for moment loads or settlements.

With member loads you will need to specify a tributary width. Only shear or global direction forces are permitted.

With plate loads or area loads, you simply pick the load to get the pressure value, only uniform pressures are used.



4 Analyze

4.1 Analysis Topics

Introduction

Analysis is the step where you determine the behavior of your structural model under the applied loads by obtainingresults: displacements, reactions, and internal forces. VisualAnalysis offers sophisticated finite-element analysisfeatures, presented in an easy-to-use fashion. The software tries to help you as you construct the model and performanalysis, but you still should know something of finite element theory and practice before you can really appreciate anduse this tool effectively.

These topics introduce analysis concepts that you will need to understand:

Understanding Analysis (Section 4.2): procedures, settings, tips, and troubleshootingStatic Analysis (Section 4.5): 1st order, P-Delta, D.A.M, and iterative nonlinearDynamic Analysis (Section 4.6): mode shapes, and responseAnalysis Performance (Section 4.4): settings and tips.Batch-File Analysis (Section 8.10): run VisualAnalysis remotely, from a command-line

Advanced Analysis

Nonlinear Analysis (Section 4.3): Watch out!Time History Analysis (Section 4.7): seismic analysis, or machine vibrationEnvelope Analysis (Section 4.9): quick location of extreme resultsResult Superposition (Section 4.8): used to combined static, dynamic, or moving load results

References

Finite element analysis is a sophisticated science that also requires practical knowledge. There are many textbooks thatprovide mathematical reference for FEA technology, but few of these help much with the general practice in the field ofcivil/structural analysis. For that we recommend your colleagues along with trial-and-error! To get a feel for how thesystem works, try solving problems for which you already know the solution so that you can better understand thelimitations and assumptions built into the software.

General Reference

Finite Element Method: A Practical CourseBy S. S. Quek, G. R. Liu2003, Butterworth-Heinemann ISBN: 978-0750658669

Finite Element Modeling for Stress AnalysisBy Robert D. Cook1995, John Wiley & Sons ISBN: 978-0471107743

Dynamic Analysis

Structural Dynamics Theory and ComputationPaz, M.,Van Nostrand Reinhold, 3rd Edition, 1991, ISBN: 978-1461579205

4.2 Understanding AnalysisVisualAnalysis uses a Finite Element Analysis method (FEA). This numerical procedure is beyond the scope of this help



file, but the following offer practical guidelines for applying the method. For information about the implementation(theory and assumptions) be sure to look at the references in the various analysis topics.

Get Ready For Analysis

The following checklist outlines many common problems that you should check to ensure a successful analysis. Many ofthese issues are addressed automatically in VisualAnalysis through the Tools | Model Check menu command. Thiscommand checks many of the discussed items below and provides the results in a report. These issues need to becorrected before an analysis is performed.

1. Geometry is properly defined using members, plates, and springs. Your model does not contain a mechanism.2. Enough nodes are properly constrained using supports or spring supports to prevent the model from having rigid

body displacement or rotation in any direction.3. Any Equation and Factored Load Combinations include at least one Service Load Case with a non-zero factor.

Included cases must not all be empty.4. If you need to perform a 2nd order (P-Delta) analysis, your model must not contain one-way members or one-

way spring supports.5. If you intend to perform a mode-shape or response spectrum dynamic analysis, your model should not contain

any one-way members or one-way spring supports.

Understand Analysis Limitations

With the exception of P-Delta analysis results, VisualAnalysis assumes that the deformation of the structure is not largeenough to severely affect equilibrium. Most often it is large rotations of members and plates that can bend that cancause results in the finite elements to deviate from their real-world behavior. Currently, VisualAnalysis does notimplement any finite elements that can handle large rotations, therefore you should always question their results ifdeflections appear large.

One indicator of problems will be that theStatics Check tabulated on the Results tab of the Project Manager (or in areport) will show a difference between the Applied Loads and Reaction forces and moments. This is a key indicator thatequilibrium of the structure has not been met and that your results are questionable. The reaction results are based onthe deformed shape of the structure whereas the Applied results are based on the undeformed shape. When thesedeviate (which should never happen in reality) deflections are large enough to generate false results.

When P-Delta results are shown, a process in which stiffness nonlinearity resulting from large axial forces and stressesis taken into account. VisualAnalysis utilizes an iteration approach as described below which has the effect of accountingfor bending magnification of structures resulting from lateral motions. P-Delta results can be different from real-worldbehavior especially when large deflections are predicted.



Stresses are assumed to be small so that the classical first derivative definitions apply. In addition, rotations anddisplacements are also assumed to be small. If any of these assumptions are violated for the actual structureresponse, the use of VisualAnalysis as a prediction tool must be questioned.

Presently, the only material model utilized by VisualAnalysis is an isotropic model. Material properties are assumed thesame in all directions. If materials are orthotropic or anisotropic, VisualAnalysis may be unable to accurately predictresponse.

Investigate Large Displacements

It is possible to analyze without error or warning messages and yet have results that are meaningless. VisualAnalysiswill make a check and provide a warning if it detects "large displacements". However, there is no fixed definition ofwhat is large.

VisualAnalysis tries to safeguard against this. However, in structures where loads have been misapplied, or geometricand material properties have been incorrectly entered, large displacements can arise. You may get large displacementsif you do not use reasonable preliminary sizes for members and plates.

Investigate Yielding, Cracking, Crushing, Buckling

Your linear analysis may "succeed" in VisualAnalysis, but your results may not be realistic! The software may report (inignorance) that the stress in your steel member is well beyond the material's yield stress. The software may providesome checks against abnormally large stresses that would cause yielding, cracking or crushing of materials, but youshould verify that your forces and stresses are within reasonable limits. Nonlinear analysis can help, but even that isincomplete or easily fooled. Design checks will account for some of these items, but you must make sure analysisresults are reasonable before trusting any design checks.

Remove Analysis Results

Removing analysis results manually is no longer possible. Any change you make that would invalidate results, does so,and then simply restarts the background process. Results are not saved in project-files. The background processing willnot slow down your editing in VisualAnalysis.

4.3 Nonlinear Theory

Linear Assumptions



In the usual linear analysis we are used to dealing with, response is directly proportional to load. In a linear analysiswe assume that displacements and rotations are small, supports do not settle, stress is directly proportional tostrain with Young's Modulus, and loads maintain their original directions as the structure deforms. In general,equilibrium equations are written for the original support conditions, elastic stress-strain relations, load-freeconfiguration, and load directions.

Nonlinear Issues

Unfortunately, for nonlinear analysis, the linear assumptions are no longer true. Nonlinearity makes a problem morecomplicated because equations that describe the solution must incorporate conditions not fully known until the solutionis known - i.e. the actual configuration, loading condition, state of stress, and support condition. Therefore, the solutioncannot be determined in a single step and iteration is necessary to converge on the correct solution.

In a sense a nonlinear analysis is somewhat more restrictive than a linear analysis. For example, the principle ofsuperposition does not apply; we cannot scale results in proportion to load or combine results from different loadcases as in a linear analysis. Accordingly, each individual load case requires a separate analysis. In essence, we justwant you to be aware that many of these new features use nonlinear analysis techniques and the assumptions andresults should be interpreted carefully.

Geometric Nonlinearity

Nonlinear problems are widely categorized in two categories; geometric and material. A common example of geometricnonlinearity is a cantilevered beam with a very large tip load. As the beam deflects it rotates and the tip load "follows"the beam thereby not acting solely in the direction it was originally applied. The cable elements (Section 2.6) are aprime example of geometrical nonlinear behavior.

Material Nonlinearity

A common example of material nonlinearity is cracking concrete. As you load a concrete member near its ultimatecapacity and beyond it exhibits highly nonlinear behavior due to the concrete material. Another example is theformation of a plastic-hinge in steel.

Types of Nonlinear Analysis in VisualAnalysis

The use of some nonlinear features in VisualAnalysis will preclude the use of others in the same project. If you find anfeature disabled, it could be due to other features already present in your model.

One-Way Elements (Section 2.4): Add tension-only or compression-only members or spring supports(Section 2.3) to the model to get an iterated first-order analysis that adds/removes elements, providingnonlinear results. (This is the only nonlinear feature that does NOT require the advanced-level ofVisualAnalysis.)P-Delta (Section 4.5): Iterated first-order analysis to include 2nd-order effectsAISC Direct Analysis (Section 4.5): Iterated P-Delta Analysis, including out-of-alignment adjustments,reduced stiffness of steel members, and notional loading.Time History (Section 4.7): (Section 4.7) Time-dependent effects (forcing function) and inertial terms.You create a TIme History Load Case to get this.Cable Elements (Section 2.6): Add cable elements to the model to get a nonlinear analysis.Semi-Rigid Member Ends (Section 2.10): Yielding or cracking as a function of load at the ends of amember element. Mark the end(s) of members as semi-rigid connections to get a nonlinear analysis.

References

For more about nonlinear analysis and other aspects of finite element analysis there is a good text by Cook that werecommend.

1. Finite Element Modeling for Stress Analysis by Robert D. Cook. John Wiley & Sons, 1995 ISBN 0-471-10774-3.



4.4 Analysis PerformanceAnalysis performance is proportional to the number of nodes, N, you have in your model, with analysis-time increasingon the order of N3. It is also directly proportional to the number of load cases and combinations that you analyze.Memory requirements are similarly impacted, though less so as VisualAnalysis is now uses a 64-bit memory model,limited essentially by the RAM memory you have installed. The information here will help you 'contain' your projects andget solutions.

Other factors that will directly impact your analysis-time include nonlinear features such as one-way elements, semi-rigid end connections, and cable elements. Time-history and moving loads are also relatively expensive.

Understand Member Results

The member element in VisualAnalysis can be used to accurately model behavior for a multitude of applied loads. Endforces and rotations in a static analysis are "exact" based on the elasticity theory. However, intermediate results alongthe length of a member are calculated only at discrete positions. This leads to small errors between these result points.

When we calculate intermediate member results (moments, shears, stresses, and displacements) each member isbroken into sections. Each section requires equilibrium calculations and computer memory. More sections yieldsmoother, more precise results but also require more time and computer memory. An ideal solution balances computerresources and accuracy.

By default, VisualAnalysis will automatically adjust the number of member result sections based on the size of yourmodel and the types of loads on a given member in each load case. This will give you the best results for small projectsand reasonable results for large projects.

The number of result sections is independent of how you report your results or see them graphically. For display, weinterpolate linearly between the calculated results positions and the reported positions. Although you can sometimes"miss" critical results by reporting too few positions along a member, you will never improve your results by reportingthem at more places than were calculated! Some result tables will automatically search the calculated results to findextreme values for you.

Set Member Result Sections

Use Project Settings, Performance to adjust how VisualAnalysis will create member result sections. This setting willalso affect the accuracy of area loads distributed to members, which are calculated using numerical integration. Hereare the choices available:

Setting DescriptionAutomatic Internally adjusts number of member result sections based on the model size. This is the default

setting.Academic Uses a large number of member result sections to get very accurate results and smooth diagrams. This

is the slowest performance setting.

Normal Provides a dynamic balance between accuracy and computer resources. Good for most real-worldprojects.

Fast Reduces the number of result sections down to a minimum for best performance. Intermediate resultswill be crude and you may miss peak moments if they do not fall near the center of members or if youhave concentrated loads. Sometimes necessary for very large projects.

Custom You decide how many sections to use for member results. There are four settings depending on thetypes of loads on a member in each load case. You should specify odd numbers to get a result point atthe center. The minimum value is 3: end points and midpoint results only.

Minimize Plate Element Sizes



Plate elements are approximate. To get good results you will need to use a mesh of elements. To know if you havegood results, you will need to run multiple models, with successively more elements and then compare these results tosee if the results are converging on the "true" solution. (Remember, the theory tells us that as we make the platessmaller and smaller, we will converge if we have a converging element, something VisualAnalysis has.)

The best approach, from a performance standpoint, is to start with some minimum number of plate elements. Use justenough to model the geometry of your structure. Then work from this point. Use the Structure | Split Plates featureto refine the model after loads are applied. When successive refinements give the same results (displacements, forces,etc.) as the last iteration, the plate mesh is probably adequate.

Auto-meshed plates are generated automatically based on the Project Settings, Auto-Mesh Factor, and you can seta desired plate count on individual Areas for more fine-grained control. With complex areas and connectivity constraintswith other members and plates, a model with lots of meshed areas can generate lots of plates and become somewhatinsensitive to your "requests" for number of plates.

Control Dynamic Mass Distribution

In a static analysis, member behavior is exact. In a dynamic analysis a member's mass is lumped at its nodes. In orderto get the best dynamic results, you might consider splitting members into multiple pieces. However, the moreelements you have the slower the performance.

You might use a trial and error procedure starting with single members, analyzing, splitting, and re-analyzing tocompare results. Repeat this process until you are comfortable that the results are converging toward the real-worldsystem of distributed mass.

4.5 Static Analysis

Common Assumptions

VisualAnalysis makes certain analysis assumptions in ALL types of analysis that it performs. VisualAnalysis checks forcommon problems after the analysis and will warn about some things, but cannot catch all possible problems.

Materials are assumed linear, elastic, and isotropic, no yielding, cracking, or crushingDisplacements and Rotations are "small"We do not consider geometric nonlinearity (except within a cable element)

You can fool yourself into getting analysis results that make no sense because they really violate assumptions ofthe program. Be sure to check your analysis results, also making use of the Statics Check, and the ResultValidation report.

VisualAnalysis supports three methods for static analysis. You define which type to use in the Project Settings(Section 2.2) settings in the Modify tab of Project Manager. Your model can also dictate an analysis type!

Non P-Delta Analysis

1st Order Analysis (Linear Model)

A first-order analysis is linear and does not account for geometric stiffness. It is the fastest type and is often agood place to start when debugging models to insure that they are basically stable. The method will blindly calculateerroneous results given a crazy model or ridiculous loads. The principle of superposition of results is valid for staticlinear analyses. Most properly designed structures acting under normal design loads will behave in a manner that isadequately predicted by a static linear analysis.

Iterated First Order (Nonlinear model)

If you have one-way members or springs, cable elements, or semi-rigid connections, then the modelis nonlinear (Section 4.3). For one-way elements, the analysis is iterated to determine which elements violate



their constraints. Results from separate load cases may not make sense if superimposed, and superpositionis theoretically invalid.

The iterative procedure performs automatically what you would do manually. For the first run on any load case all ofthe one-way elements are included in the model. Forces are then calculated for the one-way elements, and if anyconstraints are violated, those elements are removed. If elements have been removed, another analysis is performedon the modified structure. Again, forces are calculated to determine whether or not violations exist. and if so, theseelements are removed. In addition, the removed elements are checked to see if they should be returned to the modelby calculating what force they would have had. If changes are made the analysis is repeated for the modified model.

This process repeats until no changes are necessary or until the iteration limit is reached. There is no guarantee thatthis type of analysis will succeed (converge to a solution). If too many elements are removed the model may becomeunstable. If too many elements are marked as one-way, the software may "bog down" trying all the possiblecombinations. If you have problems, we recommend that you take a semi-manual approach to modeling your projectand keep the number of one-way elements to a minimum.

P-Delta Analysis

VisualAnalysis has the ability to consider geometric stiffness effects for both members and plate elements. These P-Delta results are only available when geometric or material nonlinearity is not present from elements such as one-waysprings or semi-rigid end connections without constant rigidity.

P-Delta analysis is handled by adding the geometric stiffness to the structure’s total stiffness. The process is iterativebecause geometric stiffness depends on member forces, which are not known until after the analysis.

When P-Delta results are presented, two effects are incorporated into the results, P-big-Delta (P-D), and P-little-delta(P-d). The first effect applies to members only and involves a modified bending moment acting along the length of themember. P-D is demonstrated in the sketch below. You can easily imagine how the columns will experience not just anaxial loads (1st order analysis shows this) but also a moment equal to the vertical force, P, multiplied by thedisplacement, D.

The P-d effect is generally less important and results from the bent shape of a member that is carrying an axial force. In the above sketch, the columns are no longer straight after the initial analysis, resulting in not just the P-D moment,but also a P-d moment that varies over the length of the member. VisualAnalysis does not calculate p-d directly,but this is not a serious problem because the largest moments in a frame under lateral force sway generally occur atthe column ends where p-d is zero. If p-d is a concern, dividing each column into several segments between floorlevels will introduce the effect.

The VisualAnalysis Procedure for P-Delta Analysis

First, a standard first-order analysis is performed to calculate the deflection, D. Then, additional passes of "deflected"analyses are made with the deflected shape of the structure, resulting in potentially more moments. The iterativeprocess is continued until either results converge, some maximum iteration limit is reached, or results start to diverge(some element's stiffness goes 'negative' indicating buckling). The results are based on the final "deflected" run.

In all cases when d or D are "large" you should carefully examine the results (as you should with any computer



program). The potential problems resulting from large deflections and rotations have been discussed above. If theseassumptions are violated, the results are no longer valid.

Direct Analysis Method (DAM)

AISC Direct Analysis

AISC introduced a new type of analysis in their 13th edition of the Steel Design Manual. This second order P-Deltaanalysis includes additional features to account for known problems in structures:

Members are not initially straightBuildings are not exactly plumbSteel members have residual stresses from fabrication processes

Calculating Direct Analysis

Chapter C of the American Institute of Steel Construction (AISC) manual is a radical deviation from previous AISCprovisions for several reasons which affect how structural engineers must design steel frame systems. Probably themost difficult of the new provisions arises from the moment magnification effect due to steel member out-of-plumbnessand out-of-straightness. In previous AISC codes this was handled indirectly though LRFD phi factors and ASD safetyfactors. With Direct Analysis these effects are handled through the application of notional loads. VisualAnalysisautomatically will calculate where notional loads should be applied, in which directions, their magnitudes, and will alsogenerate new load combinations to include them with the correct sets of loads. This is not a trivial task, even insoftware. It is something nobody will ever do by hand for a non-trivial structural model!

The second consideration that AISC now emphasizes is member stiffness reduction arising from residual stress. This isaccomplished in the DAM directly through stiffness reduction (EA and EI) applied to members automatically during theanalysis. With previous AISC codes, or when not using DAM, it is handled indirectly by effective length factors that areextremely complex to calculate (and therefore often poorly approximated in practice). Again, VisualAnalysis willautomatically incorporate the reduced stiffness values for members during the DAM.

Using Direct Analysis

What do these requirements mean to an engineer using a computer program like VisualAnalysis? The amount ofmoment magnification must be categorized as either moderate or severe by calculating the story drifts at each level inyour structure. AISC requires you to calculate the ratio of 2nd-Order drift to 1st-Order drift. AISC Section C2.2 statesthat when the second/first order drifts exceed 1.5, the Direct Analysis Method of Appendix 7 is required otherwise, lessintensive methods described in sections C2.2a and C2.2b are allowed.

To help you determine if DAM is necessary, VisualAnalysis now has a report to show the 2nd-Order/1st-Order story driftratios for comparison, called Diaphragm Drift Results.

Validating and Reporting on DAM

There are two new report tables that can be used with either 2nd-Order analysis (P-Delta or DAM). The first reporttable is the Diaphragm Drift Results. This report includes the ratio of second order to first order drift in each of theglobal in-plane directions for each diaphragm level in the structure. The report includes the node and second order driftfor the location where the maximum second/first order ratio value listed. Note that AISC requires the Direct AnalysisMethod whenever the second/first order ratio exceeds 1.5.

A second report item available is the Member Moment Magnification table. This table lists the 2nd-Order and 1st-Ordermoments about for each member and the ratio of 2nd-Order/1st-Order moments. The result case where the largestratio occurred is also indicated in parenthesis, keyed to a Result Cases table you may also include in the report. Thistable is useful for determining the second order P-Delta effects on your structural members.

Finally, while notional loads are automatic, and generally invisible, you can see their effects in an indirect way.VisualAnalysis reports a Statics Check for each result case (shown in the Results tab of Project Manager, or inreports). This statics check will show total loads ad reactions in the lateral directions for your gravity load combinations.You can use this to help verify the magnitudes of the loads and to see that they were actually applied.

DAM Notional Loads



http://www.aisc.org/

What is a “notional” load? Simply put, it is a percentage of the gravity load applied laterally to the structure, typically0.2% of gravity. AISC C2.2 requires the application of this load in both building plan directions for each gravity-load-only load case therefore the analysis must have 2x the number of gravity load cases it used to have. If you haveselected the DAM, VisualAnalysis now creates these new load cases automatically and applies the loads (behind thescenes) during analysis.

The way we set the notional load direction is to look at applied forces in each load case and if the resultant in acoordinate direction is a positive direction we put the notional in the positive direction and vice versa for negative. Ifthere is no lateral load in the notional direction we just put it in the positive direction. If you apply loads in bothhorizontal directions in different load cases, you will get notional loads in both directions.

Is DAM "Required" by AISC?

An interesting note is that the load cases used to calculate ratios needs to be at strength level, i.e. using LRFDequations. ASD equations are allowed but must be multiplied by 1.6 which effectively shuts down ASD as an option.VisualAnalysis only uses LRFD equations in its reporting, and does not support ASD design checks (Section 5.2) withDAM.

Whether or not DAM is necessary, AISC requires that notional loads must be applied to model the crookedness affectsoccurred during fabrication and erection. In the case of the C2.2 provisions, AISC also throws the residual stressstiffness loss into the notional loads. The DAM requires the notional loads be applied to all load cases used for design. IfC2.2 provisions are allowed, notional loads need only be applied to the gravity load cases.

So far, little has been said about the provisions in AISC (sections C2.2a and C2.2b) that might let you avoid DAM, whichare allowed when the drift ratio is less than or equal to 1.5. It is the opinion of the developers of VisualAnalysis thatthese provisions have become obsolete for several reasons.

First, notional loads and their additional load cases are still necessary, albeit they may not be necessary for loadcases with directional loads. These notional load cases can control the design of structures with heavy gravity loads andlight lateral loads which might have a lower drift ratio.

Sections C2.2a and C2.2b represent methods which use either a) second order analysis results, or b) magnified firstorder results. In the case of magnified first order results, the B1 and B2 factors of previous codes must be calculated.These are not calculated by VisualAnalysis and can require the more difficult evaluation of the K2 effective length factorper the commentary equations C-C2-5 and C-C2-8, and all the ugly caveats described in that section of thecommentary.

It is our opinion that the effort required in these provisions can easily outweigh using the DAM and the allowed K=1 indesign, and that in practice, AISC is pushing the DAM method very hard!

DAM Summary

In summary, the changes to VisualAnalysis to accommodate AISC have involved implementing the Direct AnalysisMethod described in Appendix 7. The generation of notional load cases (LRFD) is automatic for this method. Stiffnessreductions required in the DAM are also handled in the program during analysis. Finally, the P-D requirements are takencare of using geometric stiffness in our second order analysis. VisualAnalysis will automatically utilize effective lengthfactor K = 1 in your steel member designs with the DAM and will meet the Chapter C provisions.

Approximations in Static Analysis

When modeling with Plate Elements (Section 2.5) it is important to recognize that these elements areapproximations (unlike members which offer "true" solutions to the elasticity equations). You will need to use meshrefinement or other techniques to determine if your results are good. Please see the plate element topic for moredetails.

4.6 Dynamic AnalysisA modal analysis is used to determine the fundamental frequencies of vibration for a structure. This can be useful forisolating vibration problems due to machinery, human activity or seismic events. A response analysis is a simplified



way to estimate seismic or similar dynamic effects using modal-superposition. The time-history response of astructure is most simply the response (motion or force) of the structure evaluated as a function of time including inertialeffects.

Member elements are approximate for dynamic analysis, unlike a static first-order analysis. Splitting members intomultiple pieces may better mode shapes, due to better mass distribution, especially if you are investigating a very smallmodel.

VisualAnalysis advanced provides design-checks for dynamic analysis results through Result SuperpositionCombinations (Section 4.8).

Mass vs. Weight

The weight (or mass) of your model is less than the weight of the real structure--and that extra weight is critical formodeling. Weight is the effect of gravity on the mass. In a dynamic analysis the mass of the structure moves in anydirection, so it is the inertial effects on that mass that we are analyzing.

In a dynamic analysis you need to model both the stiffness and the mass of the structure correctly. The modal analysiscalculates undamped frequencies and mode shapes for the structure. Lumped mass properties are used in theanalysis, which comes from three sources:

1. Mass associated with the structural members and plates. Included automatically based on materialdensity and element sizes. This mass is lumped at the nodes, except for tapered members, where a consistentmass matrix is used.

2. Additional mass you include at each node. You should apply concentrated masses at the nodes to accountfor any mass not associated with the structural elements themselves. Rotational mass should be applied wherethere exist nonstructural entities that are affixed to the structure and have appreciable rotational inertia.

3. Additional mass you include through a static load case. The load case and global direction are specified inthe Mode Shape Case.

The sum of this mass for the structure can be included in a report. You should check this total to make sure that youhave accounted for all the mass in the structure.

Reports generated for a dynamic modal analysis provide the nodal displacements for each mode shape. Thesedisplacements are not "real" values but rather shape displacements resulting from the modal solution. Mode shapevalues in VisualAnalysis reports are based on normalization to a unit mass matrix, in other words, the value S(Mi x Di

2 )= 1, where:

Mi = mass associated with degree of freedom i, Di = modal displacement associated with degree of freedom i. The sumis carried out for all degrees of freedom in the structure. Frequency, period, and modal weight participation factors (foreach direction) are shown in the title bar of each mode shape Result View.

Mode Shapes

Mode shapes are generated through a Mode Shape Case. Create these using the Dynamic Cases tab of Load CaseManager.

You will need to consider how many mode shapes are necessary. Theoretically, there is one mode shape for eachdegree of freedom in your model. Generally only the first few in each direction are really important. Still, you may needto generate many mode shapes to obtain a few in each direction. VisualAnalysis extracts the lowest frequencies (largestperiods) from the frequency spectrum, unless you specify a minimum frequency.

VisualAnalysis uses a Sparse Lanzcos procedure which has proven to be very robust.

Find Dynamic Response

Use the Load Case Manager to create a Dynamic Response Case. The load case does not use any loads, but relieson results from a Mode Shape Case, which is a set of mode shapes.

Modal weight participation factors are normally checked to see if enough mode shapes have been included in a



response spectrum analysis. Building codes usually require a percentage (like 90%) of all the modal weight to beaccounted for when performing a modal superposition analysis. These are calculated for all translational directions inthe model. For a discussion of the effective modal weight calculation, see the following reference.

Response Spectrum Analysis is based on modal superposition. Results from a modal superposition analysis are all non-negative numbers. This includes displacements, forces, and stresses. You may select from the CQC method, or the oldSRSS method:

CQC Method

This commonly used method allows specification of a uniform modal damping factor. This method and the combinationequation are outlined in the following reference:

Mario Paz & William Leigh Structural Dynamics Theory and Computation, Springer, 5th Ed. 2006ISBN: 978-1402076671.

Symbol DefinitionU Response (force, moment, translations, etc.)UIXX Response in Ith mode, X earthquake direction, X spectrum input

UIXY Response in Ith mode, X earthquake direction, Y spectrum input

… …UIZZ Response in Ith mode, Z earthquake direction, Z spectrum input

SRSS Method (Square Root of the Sum of the Squares)

All sums are sums of absolute values.

UIIX = UIXX + UIXY + UIXZUIX = Ö (U1IX2 + U2IX

2 + U3IX2 + . . . + UNIX

2)N = Number of Modes

4.7 Time History AnalysisRequires: Advanced LevelThe Time History response of a structure is simply the response (motion or force) of the structure evaluated as afunction of time including inertial effects. The time history analysis in the advanced level of VisualAnalysis allows fourmain loading types. These include base accelerations, base displacements, factored forcing functions, and harmonicallyvarying force input.

Harmonic Forcing Function

The harmonic forcing function varies in a sinusoidal fashion and requires Ao and ω to be specified. The equation takeson the form A(t) = Ao*sin(ω*t) and A(t) multiplies all static loads placed in the time history load case at various times.Harmonically varying loads are probably most common when analyzing the effects of machinery on a structure. Oftenunbalanced rotating machinery or parts are most applicable. Note that the units on ω are such that ω*t has angle unitsof radians.

Factored Forcing Functions (Load Amplitude)

The Load Amplitude time history option essentially uses a text file to specify the fraction of the load at specific times.The text file requires two columns, time (t) and A(t) which is the amplification factor. Shown below is a sample of whatwould appear in the text file along with a plot of the data. Note the text "Force" on the first line. When this text file isread into VisualAnalysis the first line indicates the type of data.

Force0.0 0.00.05 1.0



0.1 1.00.1001 0.09.0 0.0

As with the harmonic function, A(t) multiplies the static loads applied to the structure in the time history load case atvarious times. Load Amplitude loads are commonly used to model wind loads, impact loads, and possibly blast loadings.

Base Displacement

Like the Load Amplitude loading type, the Base Displacement uses a text file for input. The base displacement is exactlyas it sounds, the structure is forced through some varying ground displacement over time. These displacements can actindependently in the global X, Y, and Z directions. The displacements can be any combination of all or some of thesedirections. (I.e. If you wanted to model an event at a 45 degree angle to the X and Y directions you could specify thenecessary components in the X and Y directions respectively.) Units for the text file are always assumed to be secondsand inches. After the file is read in the data will be converted to the current unit system. For example, if one of thedisplacement values was 6 in it would be read in as 0.5 ft if your current project units were lb-ft. The text file requiresat least two columns and can have up to four (refer to the Text File Notes section below for more information). Thesecolumns would be the time, t, ux(t), uy(t), and uz(t).

Displacement0.0 0.0 0.0 0.01.0 5.0 0.0 0.02.0 -5.0 0.0 0.03.0 5.0 0.0 0.0

Note that the line is extrapolated linearly between the t = 2.0s and t = 3.0s values but our time increments limit thedisplacement to 2.5 seconds. In the example the uy(t) and uz(t) columns are included but have no effect. Note alsothat if you are working in a plane structure the uz(t) column will always be ignored.

Base Acceleration

Again, the Base Acceleration loading type uses a text file for input. The base acceleration is very similar to the basedisplacement and represents putting the structure through some varying ground acceleration over time. Logically, thebase acceleration is just the second derivatives of the base displacements. Similarly, the accelerations can act in the x,y, and z directions and again they can be any combination of all or some of these directions. The text file requires atleast two columns and can have up to four (refer to the Text File Notes section below for more information). Thesecolumns would be time (t), űx(t), űy(t), and űz(t) where the accelerations are specified as a decimal fraction of G (I.e."0.5" would be 50% of G). Note below the text file is shown in a space delimited format.



Acceleration0.0 0.0 0.0 0.01.0 1.0 0.0 0.02.0 0.0 0.0 0.02.01 0.0 0.0 0.03.0 0.0 0.0 0.0

Base Displacement and Base Acceleration Notes

With the base displacement and base acceleration analysis types static loads only have an inertial effect on thestructure. With the harmonic and amplitude analysis types, the static loads applied within the time history case arevaried dynamically according to what is specified. For the displacement and acceleration types, VisualAnalysis convertsany statically applied load in the time history load case acting in the positive or negative Y direction to a mass. It thenhas an inertial effect on the results similar to adding lumped mass to nodes. Any statically applied loads that do not actin the gravity direction (positive or negative Y) and any moments are simply ignored by VisualAnalysis and will have noeffect on the displacement or acceleration analysis results.

Text File Notes

Some general notes about the input text files. The text files can be comma, space, or tab delimited. The Force,Displacement, or Acceleration "headings" on the first line are not essential for the file to work but it is recommended.

Once the data file is opened and read successfully, the data is stored in your project file (*.vap) and the connection tothe data file is not maintained. If you edit or modify your data file, you would need to edit the Time History load case tore-load the data from the file. Storing the data file in the project file allows the project to be sent to a colleague oropened at some future time when the text file is not available or may have a different location.

Lastly, the values in the text files are always linearly interpolated until you set a new value. For example, in the sampleacceleration data we wanted the acceleration to be zero at a time of 2 seconds and beyond. To accomplish this wespecified an acceleration of zero at t = 2.0 sec and also at t = 2.01 sec. If we had not added the t = 2.01 sec entry theprogram would simply have continued to interpolate a straight line between the acceleration of 1 at t = 1 sec and zeroat t = 2.0 sec and continuing on past 2.0 seconds.

Amplitude, Acceleration, and Displacement Input

In time history analysis procedures there are a number of ways to numerically integrate the fundamental equation ofmotion. Many of these are discussed in text books including the referenced texts included in this document.VisualAnalysis uses the Newmark method of numerical integration which is considered a generalization of the linearacceleration method. The parameters of the Newmark method are described in what follows.

Number of Steps – This is the number of time steps over which you wish to analyze.

Delta t – This is the time increment for each step. The time step increment can be very important as well. E.L. Wilsonin [3] recommends ∆t ≤ 1/(ωMAX*√(γ/2 - β)). For large multi degree of freedom structural systems there is a differentlimit. This due to computer models of large real structures normally containing a large number of periods which aresmaller than the integration time step; therefore, it is essential that one select a numerical integration method that isunconditional for all time steps. For a further discussion refer to [1], [3], and [4].



Gamma and Beta – The Newmark method is basically considered a generalization of the linear acceleration method(Wilson-Theta). Gamma and Beta replaced the 1/2 and 1/6 coefficients on the incremental acceleration terms of theequation for incremental displacement, as derived by the Wilson-theta method. E.L. Wilson presents a good discussionin [3] regarding the beta and gamma parameters for Newmark's method. Many text books on the subject also describethese parameters. The default values of gamma = 1/2 and beta = 1/4 may be used unless you are sure otherwise.These default values make the Newmark method unconditionally stable and provide satisfactory accuracy. Using othervalues, particularly gamma greater than 1/2 can lead to "numerical damping" and "period elongation".

Delta – Delta defines the amount of damping and is usually defined as the logarithmic decrement, which is the naturallog of the ratio of any two successive peak amplitudes in free vibration. Note that VisualAnalysis uses viscous damping.This is the effect of internal damping due to materials, connections, etc. and adding mass to the structure. Mostdynamics texts discuss damping including those referenced below.

Relating to mass, note that it is usually more accurate to split the members of your model to get a better massdistribution and a better solution. This is discussed for mode shapes and response spectra and applies to time historyanalysis too. You can also refer to the Time History tutorial where members are split to improve the analysis accuracy.

Time History Results

The unique characteristic of time history cases is you can view results for every time step. A very useful way to look atresults is to use the graph feature. For example, while in a Result View you can right click a node in your time historycase and select "Graph Node Results" from the context menu. This will allow you to plot displacement, forces, andmoments over time for the selected node.

Time History Reports

There are three main report items available for time history load cases: Time History Cases, Forcing Function Details,and Forcing Function Summary. The Time History Cases item includes a number of items with the most common onesbeing the number of time steps, time step increment, gamma, beta, and delta values, and the forcing type. The ForcingFunction Details and Forcing Function Summary report items are very similar. They both include the time history casename, the forcing type, the location of the source text file that was used (if applicable) and the number of data points.The only extra information the Forcing Function Details report gives is the data that was read in from the text file in atabled format. Note that many of the static reports are available at a specific time increment in a time history analysis.For example, you can view member internal forces at any of the time increments during the analysis. Also, the use ofenveloped results becomes very useful for processing time history results. Logically, using an envelope would quicklyallow you to see the overall maximum and minimum extremes for just the time history case or for multiple load cases.Refer to the Enveloped Results section for more information.

References

1. Structural Dynamics: Theory and Computation by Mario Paz. 5th Edition. Springer, 2006 ISBN 978-1402076671.2. Structural Dynamics by Finite Elements by William Weaver, Jr. and Paul R. Johnston. Prentice-Hall, Inc.

Copyright 1987. ISBN: 0-13-853508-6.3. Dynamic Analysis by E.L. Wilson. 4. Dynamic Analysis by Numerical Integration by E.L. Wilson. 5. Seismic Analysis Modeling to Satisfy Building Codes by E.L. Wilson.

4.8 Result SuperpositionRequires: Advanced Level

What is a Result Superposition?

VisualAnalysis has the ability to superimpose the analysis results to create a post-analysis load combination. This isuseful for combining loads that cannot be combined before analysis. You will want to use this feature to combine static



and dynamic results or to combine results from moving loads with other static results. This type of combination willgenerally consist of an envelope pair (extreme minimum and extreme maximum) results, depending on whether any ofthe results you include are 'extreme only' results. The extreme only result cases include the time-history enveloperesults, and the moving load case results.

The superposition is carried using simple algebraic summing of like results from each result case. There is no speciallogic or intelligence in the process. When an envelope is included, the normal results from simple result cases are addedto both the extreme minimums and the extreme maximums.

How to Use

To access this feature use the Load Case Manager, Advanced tab, and select which possible result items to include.You can create this combination before you have analysis results. After analysis this combination will only containresults if all of the included result-sources actually exist.

Superposition combinations may be marked as a design load combination (ASD, LRFD, or deflection). This is theapproach to take to get design checks (Section 5.1.2) for moving load results (Section 3.8) or for dynamicresponse (Section 3.7) or time history (Section 4.7) results.

When viewing Result Views showing any envelope results, use the Filter tab in Project Manager to toggle betweenthe High Extremes and the Low Extremes.

Limitations & Details

This feature is not available if the model is nonlinear. Superposition does not apply to nonlinear analysis, so addingresult cases makes no sense. For example, if a tension-only member is removed from an analysis because it goes intotension, how can you add the results from another analysis where this member may not be in tension? VisualAnalysisdoes not allow the combination of results that could be combined before analysis, you should use the other types ofload combinations for combining static loads, for example.

VisualAnalysis allows you to combine P-Delta (2nd order analysis) results, however it will warn you that doing so isreally not valid. P-Delta analysis is nonlinear, so using superposition on the results may yield incorrect results. From apractical standpoint, it may not make a big difference, as P-Delta results are usually within 10% of the linear results, yetyou may be adding 'apples' with 'oranges'! Please exercise caution and double-check the answers you get.

Dynamic Response result cases contain only absolute values. When a Dynamic Response is combined with any otherresult cases, these positive values are added blindly during the superposition—that is, there is no intelligence in theprocess to determine a 'worst case' superposition. These positive values are added to both envelope extremes, if thesuperposition is an envelope.

Envelope result 'locations' are not retained or calculated in the superposition combination. You will not be able todetermine from a result superposition where a moving load was, or the time step from a dynamic time history analysis.

4.9 Envelope ResultsRequires: Advanced Level

Introduction

The enveloped results feature is just as it sounds: It is a way to view demands of various load cases in a single overall"Result Case". Any envelope case actually consists of two sets of results, the minimum and maximum values, these arereferred to as "Lower Extremes" and "Upper Extremes". Moving load cases and result superposition cases both produceenvelopes.

Envelope Feature

Find a check box in the Advanced tab of the Load Case Manager. You do not necessarily need to use this 'Envelope'feature to find extreme results! Reports can locate extremes and design-checks do it automatically! This 'advanced'feature allows extremes to be calculated and stored for time-history results, moving load and superposition



combinations.

Viewing and Reporting the Envelopes

As mentioned above, the process to obtain an envelope is essentially automatic. To view the resulting envelope thereare a couple of options. Just like other load cases or combinations, the Envelope Results show up on in a Result View.Use the Command Bar (Section 1.3) at the top of the Result View to select one of the Envelope Cases to display.Onthe Filter Tab of the Project Manager under the Results Display heading use Envelope Type to control which setof results "Low Extreme" or "High Extreme" to display. Note that these are the upper and lower extremes and it is verypossible for your largest moment to be negative and occur in the minimums case.

Envelope Moment Diagrams

The first option for viewing the envelope is graphically. As with other load cases you can select a member, then right-click and choose Graph Member from the context menu. This will typically default to a plot of the deflection, shear,and bending moment for the member but can be customized to include or exclude items. The Member Graph showsboth the maximum (High Extreme) and minimum (Low Extreme) for the envelope. The Low Extreme is defined by theboundary with a lower magnitude while the High Extreme forms the boundary with the higher magnitude (absolutevalue). Viewing the results of a simple cantilever beam and comparing them to the Member graph will help clarifyexactly what is being displayed. You may notice that the plots typically have sharp changes or steps in them usuallyindicating where a different load case has begun to control.

Envelope Reports

The other way to view the resulting envelope is with typical reports. The reports are very similar to member reports inother load cases. You can view Member Internal Forces, Local Displacements, and other items. As usual you have theoption of viewing just the extreme results (i.e. the extreme results of the envelope) or you can view a detailed table ofall the results along an element.

Note: Envelope results are calculated at discrete places along the length of the member. The high and low extremevalues at each location may come from completely different load cases, therefore VisualAnalysis will not linearlyinterpolate between the result-locations to produce a "summary" report, or a report showing more or fewer offsets thanwere calculated internally.. The moment diagrams are not smoothed and you may see jumps or spikes in the valuesthat for normal results you would not expect to see! To control the number of places where envelope results arecalculated, set the values in Project Settings, Performance to some upper limit.



5 Design

5.1 Concepts

5.1.1 Groups

What is a Design Group?

Design Groups are simply an association of member elements (or plate elements) for two purposes. First, they associatethe elements in VisualAnalysis with a specific material specification and its associated parameters (like code version,bracing, and deflection limits). Second, they allow you to economize your data entry and the final structure by groupingsimilar elements together. Design groups must "match" the shape that you are designing. You will not get unitychecks if you try to design a cold-formed shape with an AISC steel design group, or visa-versa. If you change theshape to a different design category (e.g. from wood to steel), you will need to delete the design group and recreateone of the appropriate type.

Design Groups are required for checks. There is no way to check members without placing them in a design group, andeach member may be in only one design group at a time. You may place each member into its own "group" if you like.

When you Design members in a design group, all the members will take on the same final member properties. Thesoftware checks all the members in the group and verifies your selected shape will satisfy the stress/force (strength)and deflection (serviceability) requirements for the worst case.

Auto-Groups

By default design groups are created automatically for you. You can control this feature through the Project Settings,Design Checks, Auto-Group. VisualAnalysis will group members with similar shapes, materials, lengths, andorientations in a semi-intelligent way. If you turn off this option then you can manually take charge of groupingmembers. Any time you manually manipulate a design group, such as removing a member, we will automatically turnoff the auto-grouping, so the system is not fighting against you.

Manual Design Groups

You can manually remove members from Design Groups and Create new groups. Use the Design tab of the mainribbon or the context menu in the Design View. For best results you will want to turn-off the Toggle Groups option inthe Filter, to allow you to select individual members rather than all the members in a group. If you add or removemembers from a design group we automatically disable the auto-group feature, which might try to fight against yourmanual operations. You may re-enable it later, as needed.

When grouping members manually, you should consider shapes, member lengths, orientations of members, materialproperties, and how the members are braced.

Some Members Cannot Be Grouped

VisualAnalysis does not support design checks for all types of members. Custom blob (Section 2.4) shapes, custommaterials, custom database shapes, and rigid-link members are all excluded from Design Groups. You may be able toperform custom stress and deflection checks (Section 5.5) on custom member elements.

5.1.2 Unity ChecksRequires: Design Level

Unity Checks

A unity check is simply the ratio of actual demand over design capacity. It is a quick pass-fail number. In some



cases the unity check represents a stress ratio, in others it is an ultimate force ratio. The unity check might alsorepresent a deflection ratio or something else entirely. All of the design load cases are checked for the member and theworst-case value is stored. These checks encompass all types of checks pertinent to the material and according to theassumptions and limitations of each design material module and your settings.

Another way to think of the unity check is as a "Percent Material Utilization" factor. If you have unity checks in therange of 0.01 to 0.25 your elements are over-designed: there is a lot of wasted material. On the other hand if yourunity check values range from 0.95 to 0.99, your elements (not necessarily the model as a whole) are optimized forleast weight.

Unity checks are normally greater than zero and less than five or ten. A value greater than one indicates a failureor that some design check has been exceeded. If you have done a good job of initially sizing your model, your unitycheck values will not exceed 1.0 by a great amount. If you see a unity check value that is negative, or very large, thatcould be an indication of an unreasonable model.

Unity check values and errors and warnings are displayed in the Design View window and the Find Tool. You canhover over a member to see quick information in the Help pane or double-click a member in the Design View to getdetailed design reporting.

Checking vs. Design

VisualAnalysis distinguishes between code checks and design.

Checks: A check of your model "as is" using the Design Group options that apply. Each member in a Design Groupmay be a different shape and is checked using that shape. Checks are generally automatic when you switch to theDesign View and analysis results are available.

Design: When you explicitly tell the software, using Design | Design Selected Group (or similar) to search for ashape that works for all members in the group; each member is then checked as if it were the chosen shape. When youdesign a group, all the members in the group take on the same final shape.

5.1.3 BracingVisualAnalysis assumes that the length of a member element is equal to the unbraced length. It is up to you when youcreate a design group, to specify the actual unbraced length for members in the group. This is one of the key criteriathat you will use in determining which members to group together. Bracing is not automatic in VisualAnalysis, you mustpay attention to this important detail. The terms top and bottom relate to the member's section axes, and may notrefer to the actual 'top' of the member! To see the location of bracing on a member use the Brace Locationscheckbox found in the Member Details section in the Filter tab while in the Design View.

Three Directions to Brace:

1. Lateral Top Bracing (at the +y face of the member), for strong flexure checks2. Lateral Bottom Bracing (at the -y face of the member), for strong flexure checks3. Strong Bracing (z), for axial compression checks.

Torsional Bracing?

VisualAnalysis does not provide a way for you to enter any torsional bracing information. The software makes theassumption that the unbraced length for torsional buckling is the minimum of the strong and weak flexural unbracedlengths, i.e. KLx = Minimum(KLy, KLz).

Ways to Specify Brace Positions

These are brace locations along the length of each member element.



UnbracedBracing Patterns (e.g. midpoint, third point)Bracing FractionsSpecified Unbraced LengthAt Interior Nodes (for members with intermediate connections)

Bracing Patterns

By default, each member element is braced at its end points and unbraced along its length. Bracing patterns allow youto define intermediate bracing points that are not part of the VisualAnalysis model.

You may specify a bracing pattern like continuous, mid-point, third-point, or quarter-point. This means that for eachmember element, a brace is assumed to restrain the member against buckling at these specific positions along themember. This is a fast and easy way to specify the bracing and it can work well even if the members are of differentlengths. You may also restore members to the default unbraced state using patterned bracing.

Bracing Fractions

By default, each member element is braced at its end points and unbraced along its length. You may use fractionalbracing to define the locations of intermediate brace points along members.

Fractional bracing is similar to Bracing Patterns but allows an essentially unlimited number of patterns. You simplyspecify that braces exist at specific fractions of the member element length. These fractions are defined from the start-end of the member element. You create a list of fractions to locate braces at arbitrary positions along each memberelement.

This method also works if member elements have differing lengths. Fractions should be listed in increasing order in therange of zero to one. For example, "0.5, 0.625, 0.79"

Specified Unbraced Length

When you specify a specific unbraced lengths, these braces are assumed to exist at fixed distances from the 'start' endof the member element until the end of the member is reached. You may specify an unbraced length that is longer thanthe member-element length to model things like a chain elements that is not exactly straight and where VisualAnalysiswill not allow a 'Combined Member'

Using the specified unbraced length can result in an incorrect calculation for the Cb value and other possible errors inchecks--please use wisely.

At Interior Nodes

VisualAnalysis provides a convenience feature that lets you combine member elements into a single composite memberfor design or reports. Behind the scenes the member consists of multiple elements with interior node points. Thedesign software does not automatically "see" the interior node points as braced points, but you may specify this optionin the bracing.

5.1.4 DeflectionsDeflections are checked for load combinations that have been marked as "Deflection" or "Allowable and Deflection "inthe Load Case Manager (Section 3.6).

You must choose the method for checking deflections! For cantilevered beams you generally need to check"total" deflection (described below). Depending on how your model is constructed (e.g. combined members orseparate member-elements), or how members are grouped together, you may need to change the type of displacementcheck! The measured displacements can change dramatically (and even reverse direction!) depending on the methodchosen.



Span Ratio vs. Actual Deflection

You may specify a limit based on a span ratio (like L/360), or a specified displacement limit (like 0.25 inches). The spanratio approach allows you to group members that may not have the same span length, yet still provide a consistentdeflection limit. You may disable specific limits by setting a zero value (for a displacement limit) or a small value (for aspan-ratio limit).

The span-length is calculated as the member-element length, or for a combined member it is the total length--regardless of the types of internal connections or supports! Span-ratio checks may not make sense for combinedmembers that are supported in their interior. Span-ratio checks generally do not work for cantilevered members.

Relative Member vs. Total Deflection

You will also need to choose between two methods of measuring the actual deflection. VisualAnalysis uses the terms"Member" and "Total" to distinguish between bending deflection in a member element and the total movement of amember including the nodal displacements.

In the picture on the right above, the member deflections are calculated from the green-line between the deflectedend-points to the red-line (the deflected beam), while the total deflections are calculated from the dashed-blue line.

In many cases, the member and total displacements will be identical. This is true for a simple span beam, or(approximately) a beam framing between two columns. In the case of a beam split into multiple elements you will needto make sure that you are checking a total displacement. In the case of a beam spanning between two girders, and thegirders are also deflecting, then you will want to check member displacements for this beam. Finally in some situationsyou will simply need to check absolute displacements that you have pre-calculated. Using the span-ratio limits does notwork for all situations in modeling, though it is most convenient for typical beams.

Load Combination Deflection Categories

You can view deflection categories in the Load Case Manager, on the combinations page for any load combinationsmarked for "Deflection" or "Allowable and Deflection" checks. See loading for design (Section 9.1.2) for moredetails.

You can specify different deflection limits for each category in a Design Group's parameters.

Column Drift Checks

VisualAnalysis does not directly check drift requirements. There are special Reports available to show building ormember drift that you may use to check your drift requirements and make frame-wide adjustments as necessary. The"Complete Member" report item will display the actual drift extremes calculated for a column member.

5.1.5 Design ParametersDesign parameters control how unity checks and design searches are performed for a Design Group (Section 5.1.1).You enter this information in the Modify tab after selecting a member or a Design Group in the Design View window.While many of these parameters are specific to the type of material you use, there are some common designparameters across some of the design modules. For example, steel, wood, and cold-form steel design all use similar



bracing, size constraints, and deflection criteria.

Bracing

Members are unbraced by default. See bracing (Section 5.1.3).

Deflection Limits

Specify the span ratio or absolute limit for allowable deflections. Select the type of deflection (Section 5.1.4) to usein the checks: relative or total.

Live Load Reduction

You can specify a live load reduction level for all the members in this design group. Only load combinations utilizing thatlevel of live loads will be checked. You set up live load reduction levels using the Load Case Manager.

Size Constraints

One common design criteria is limited space. If the architect has mandated a minimum floor to ceiling height, you willprobably need to limit the depth of your beams and girders. VisualAnalysis supports this using a size constraints. Sizeconstraints can also dramatically improve the performance of the software when searching for a least-weight memberto meet your design criteria.

If you have specified a size constraint, it will also be checked during unity checks of existing members. If a memberviolates the size constraint, there will be a "flag" on the check and the member will appear differently in the DesignView. You will see a note in the fly-over tip regarding the violation or a note in the report.

Design Material

You do not specify any design material in the Design View or Design Group parameters. Members in your model have ashape and material defined in the Model View, prior to analysis. The material is not changed by design operations, thebut shape may be.

Axial

Axial parameters provide information about the frame in which the members of this design group reside. You mayignore the axial parameters if designing members without axial loads. You have the option of overriding the effectivelength factors and can indicate whether the frame is braced or not. The directions referred to on this page areinterpreted according to the section axes of each individual member element in the group. This means that if you havea frame that is braced in one direction and not the other, you should not place members whose orientations aredifferent into the same design group.

Sidesway y: Choose yes if the member is part of a sway frame in the plane formed by its section z and local x axes.Choose no if it is part of a braced frame in this plane. If the automatic K factor calculation is on for Ky, the sidesway yparameter will effect the calculation of the Ky value.

Sidesway z: Choose yes if the member is part of a sway frame in the plane formed by its section y and local x axes.Choose no if it is part of a braced frame in this plane. If the automatic K factor calculation is on for Kz, the sidesway zparameter will effect the calculation of the Kz value.

Manual Ky: Ky is the effective length factor for buckling when the member kicks out in its section z direction(normally weak axis buckling). If Set Ky is left set to no, the effective length factor will be calculated automaticallybased on the relative rigidity of the members framing in at its end points. If Set Ky is set to yes, the Ky value must beentered.

Manual Kz: Kz is the effective length factor for buckling when the member kicks out in its section y direction(normally strong axis buckling). If Set Kz is left set to no, the effective length factor will be calculated automaticallybased on the relative rigidity of the members framing in at its end points. If Set Kz is set to yes, the Kz value must beentered.



5.2 Design Topics Requires: Design Level

Introduction

VisualAnalysis with Design, and VisualAnalysis Advanced with Design offer sophisticated code-checking and membersizing capabilities broadly classified as 'design'. The design software implements various material specifications forchecking steel, wood, concrete, and cold-formed members. A custom checking module also allows for primitive stressand deflection checks for other materials or custom shapes.

Please insure displacements and stress results from analysis are within rational limits--before you use ortrust design checks.

VisualAnalysis is also integrated with other IES products which support a variety of specialized design features asdescribed below.

Design Essentials

Design Groups (Section 5.1.1): organizing elements for design checksUnity Checks (Section 5.1.2): a pass/fail numberBracing (Section 5.1.3): Specify unbraced lengthsDeflection Checks (Section 5.1.4): Setup and types

How To

The Design Process (Section 9.1.1): The big-pictureLoading for Design (Section 9.1.2): Service cases are never checkedModeling for Design (Section 9.1.3): Member lengths are importantAnalyzing for Design (Section 9.1.4): If analysis results are bogus, design checks are worse

Design Report: Double-click on a member in a Design View to see exactly what checks controlled the design!"Design Group Results" report items include specification references, controlling load case, demand and capacity values,as well as critical intermediate results or parameters used like unbraced length, K factors, load duration factors, rebardetails, and more.

Design Types

Building Code Support (Section 1.5)Steel Design (Section 5.4) (AISC / CISC)Composite Beam Design (Section 5.8) (AISC)Aluminum Design (Section 5.6) (ADM)Wood Design (Section 5.3) (NDS)Concrete Design (Section 5.9) (ACI)

Concrete Beam Design (Section 5.10) (ACI)Concrete Column Design (Section 5.11) (ACI)Concrete Wall/Slab Design (Section 5.12) (ACI)

Cold-Formed Steel Design (Section 5.7) (AISI and more)Stress & Deflection Checks (Section 5.5) (Generic & Custom)

Foundation Design

Export to IES QuickFooting, a separate IES product for spread-footing design. This process is summarized onthe QuickFooting Design (Section 8.5) page.



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Export to IES VisualFoundation, a separate IES product for complex mat foundation design. This process issummarized on the VisualFoundation Design (Section 8.2) page.

Steel Connection Design

VisualAnalysis offers integrated steel connection design via IES VAConnect (Section 8.4), a separate suite of tools.Currently the tool provides LRFD steel design of Base Plates and Shear Tab connections.

Other Design Support

There are some report tables available (in all levels of VisualAnalysis) that can help your own design calculations orinvestigations.

Member Relative DeflectionsColumn DriftMember Moment Magnification

You may export analysis reports via the clipboard or saving to a file for further design processing on your own, perhapsin a spreadsheet or other tool.

5.3 Wood DesignRequires: Design Level

Introduction

VisualAnalysis designs beam-columns for solid sawn, post/pile, glued laminated shapes, and some structural compositelumber (LVL, PSL, etc.). Code checks performed by the program adhere to the 2012 National Design Specification (NDS)for wood construction, either ASD or LRFD.

Wood members designed by VisualAnalysis must be placed into design groups as described in general documentation.Each group has its own set of design parameters defined for it. These parameters include attributes such as species,grade, moisture conditions, etc., which are needed in order to determine the proper provisions to use for design. Acommon shape will be chosen for all members in a given group.

Assumptions

VisualAnalysis makes the following assumptions or has the limitations described below:

Connections are fabricated such that each member is loaded concentrically.Member span is conservatively taken as the full length from center-to-center of supports.Wood materials are defined with "oven-dry moisture" density, you may need to add self-weight to yourmodels!Shear force is conservatively taken at the member element's end. NDS 3.4.3.1 possible reductions are notconsidered.Some glue laminated timbers have different stress ratings for the "top" (Compression Zone per NDS) and"bottom" (Tension Zone per NDS) member laminations. The tabulated database stresses for glu-lammembers are dependent upon whether or not the intended "Tension flange" is in tension. Because of this,the assumed orientation in VisualAnalysis is critical for design. The "bottom" of glue laminated timbers isassumed at the –y (negative) face of a member (member local axes) with a beta angle of zero. Adjusting the beta angle will change orientation of the tension face in the model.When calculating the volume factor Cv, the width, b, of glued laminated timbers built up to be wider than10.75 inches is taken as 10.75 inches as mandated by NDS 5.3.6.When 4 or more laminations are used, Table 5B values assuming special tension laminations are used.Post and pile designs assume that the untreated factor, Cu, is applicable.Notches, when specified, are assumed to exist at critical shear position along the beam length.



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Capabilities

Complies with National Design Specification (NDS) for Wood Construction.NDS Shapes included in the database may be checked or designed in VisualAnalysis.New! Standard Parametric rectangle and round shapes may be checked.Performs code checks for visually and mechanically graded dimension lumber, visually graded timbers (5" x 5"and larger), round timber poles and piles, glued laminated timbers, and some structural composite lumbershapes.Checks include bending (strong & weak), shear (strong & weak), tension, compression, combined bendingand tension, combined bending and compression, and deflection (strong & weak). There is also an optionalcombined biaxial bending and tension check per AITC.Allowable stresses used in design are based on the NDS Supplement Tables 4A through 5C and NDSSpecification Tables 6A and 6B. Custom stress values may be used.Shapes used in design include those listed in NDS Supplement Tables 1B through 1D (standard dressed andglued laminated shapes), as well as a selection of rough sawn and full sawn rectangular members and posts.The database may be customized to include additional sections.Allows user-specified bracing patterns, dimension constraints (min. and max.), and deflection limits (absoluteor span ratio).Allows user-specified adjustment factors.Allows user-specified material COVE.Can account for reductions in cross sectional area due to bolt holes in axial check.Reports include tabulated stresses, factored stresses, and adjustment factors.Notch provisions of NDS 3.4.3.2 are included.NDS does not support tension design in posts or piles (it just has no information on the subject).VisualAnalysis allows you to apply a tension and will check it using an F't value of 0.5*F'c, similar to thevalues published for other shapes. A warning will be included in the design report as this value, while it maybe useful, may not be correct!

Wood Limitations

I-Joists and similar "Engineered Products" are not supported. You may be able to get preliminary checksfor these shapes using the stress-check (generic) (Section 5.5) module.There is no provision for using double-up members as is often done in practice. You may wish to useStandard Parametric rectangles to 'simulate' these shapes--with some engineering judgment!Torsion is not checked. However, any significant torsional moment is noted in design reports as a warning.Compression perpendicular to grain (bearing) is not checked.Provisions for special loading conditions (NDS Chapter 15) are not used.The program has the ability to determine the unbraced length at any point along a model member.However, members which are broken in to multiple sections in the model and have an unbraced lengthgreater than that of the individual sections will have a single unbraced length entered manually which willcontrol for all points along the member. This is overly conservative in some situations. This situation alsoapplies when considering a member's length between inflection points.Calculation of the buckling stiffness factor will be based on the greater of the model member length andits designated strong axis unbraced length. If a group of members that qualify for the buckling stiffness factorare broken into multiple segments, the strong unbraced length of the members must be changed to reflectthe appropriate length.The Cd (load duration) factor, cannot be overridden. It is affected by load combinations. (See below forspecifics).Tapered members are checked with the starting member shape as if they were prismatic.

Load Duration Factor CD



Load duration factors for wood design are specified in the NDS as a function of the longevity of applied loads. Deadloads are assumed to be permanent, and live loads are assumed to last longer than construction loads. The differenttypes of loads are associated with the duration. VisualAnalysis automatically determines what the load duration factorshould be based on the "load sources" as utilized in the design load combinations, based on the shortest durationsource. The following factors are used for load sources:

Load Source CD

Impact (untreated) 1.6

Wind or Seismic 1.6

Roof Live Loads 1.25

Snow 1.15

Live 1.0

Dead, or other loads 0.9

Impact loads are allowed a duration factor of 2.0 in the NDS, but VisualAnalysis does not use load factors higher than1.6.

Combined Checks

Bending and Axial Tension checks are performed per NDS equation C3.9.2-1. Bending and axial compression arechecked per NDS section 3.9.2.

Wood Design Parameters

The design parameters represent additional information that VisualAnalysis requires in order to correctly perform codechecks. Each time you create a new wood design group is created (automatic by default) you need to go to the Modifytab and make sure the design parameters are set up correctly for your new group. Keep in mind that the parameterinformation you enter applies to all members of the group, so it may be wise to choose the most conservativecondition that applies to any member in the group. Note: All of the parameters described below are edited/selected onthe Modify Tab of the Project Manager while in the Design View.Specification: Choose between ASD and LRFD code provisions.

Member Type: Selects general member type, changing the selection of user input parameters. By default, these areset based on member orientation in the model (i.e. Beam-horizontal, Column-Vertical)

Overstrength: Designs member for higher seismic forces based on user specified Overstrength factors and IBCSeismic Design Category.Shape Category: Chooses shape category from which the VisualAnalysis "Design" feature selects shapes to optimizedesign.

Disable Checks: Prevents design checks from being performed on the selected design group. Allows you to speedup design checks and focus on targeted areas of larger models.

Bracing Parameters:

Member Bracing - By default, member unbraced length is the equal to the member length between nodes. SeeBracing in VisualAnalysis (Section 5.1.2) for a complete description of bracing member elements for designchecks.

Axial Parameters:

See Design Parameters (Section 5.1.2).

Constraints Parameters:



Options under this heading allow you to specify depth and width limitations on the members chosen when theVisualAnalysis "Design" feature selects shapes to optimize design.

Wood Configuration Parameters

The following attributes are part of the "Configuration" category of parameters. Which configuration parameters areavailable fro a given design group depends on which Design As Shape Category (dimension lumber, timber, etc) youhave chosen.

Has Bolt Holes: This parameter is available no matter what type of wood design you are running. This parameterallows you to specify the number and size of bolt holes in the member. Note that the bolt holes only affect axial checks(pure axial and combined axial + bending). It is assumed that the bolts go through the width of the member ('b'dimension) and not the depth. It is also assumed that all bolt holes are at the same section. A third assumption is thatthe section is rectangular. This option should not be used for shape groups with circular or other non-rectangular crosssections.

Glu-Lam Member With Multiple Piece Laminations:

This parameter is only available for groups with the softwood gleam design type and when the selected combination isfrom Table 5B. It allows the program to determine the correct allowable shear stress to use, since this is dependentupon whether or not the member has multiple-piece laminations (not edge glued).

C-Factors Parameters:

Repetitive Member?

This parameter is available for Dimension Lumber, Timber, and Structurally Composite Lumber design groups. Theparameter will determine whether or not the repetitive member factor, Cr, is used.

Use Incising Factor?

Indicates whether the member has been incised (for the purposes of allowing chemical treatments to penetrate better).The software uses this parameter to determine whether or not to apply the incising factor (Ci). The software assumesthat the size and density of the incisions comply with the limits set forth in section 4.3.8 of the NDS.

Pressure Treated?

This item indicates whether this group's members have been chemically treated. Members that have been treated canhave different load duration factor (CD) values than non-treated members. the NDS limits duration factors to 1.6 forpressure treated members.

High Moisture Content

Indicates whether the member has sustained exposure to high moisture (19% for solid sawn, 16% for glu-lams). Thesoftware uses this parameter to determine the wet service factor (CM).

Use Buckling Stiffness Factor?

Indicates whether the buckling stiffness factor (CT) should be applied to the members of this group. NDS gives severalcriteria for situations in which this factor applies. Because it would be difficult for the program to try and determine thisautomatically, it is left for you to make this determination. The material KM value must also be entered. This factorapplies only to sawn lumber members. Other conditions that determine its applicability, as well as guidelines fordetermining KM, are discussed in section 4.4.2 of the NDS.

Use Single Pile Factor?



This parameter is only available for Post and Pile design groups. This option allows the Single Pile Factor (NDS 6.3.12)to be applied affecting the value of Csp.

Temperature Range

Allows you to specify if the group members will experience sustained exposure to unusually high temperatures. Thesoftware uses this parameter to determine the temperature factor (Ct).

Wood Beam Parameters

Beam Type

This is a function of the end conditions of the beam. The group members must be classified as either simply supported,cantilever, or continuous. These choices correspond to categories in NDS table 3.3.3 and are used in conjunction withthe Loading Pattern to determine the effective length (le) for members in bending. This is also used to calculate theloading condition coefficient (KL) as a part of volume factor (CV) calculations for glu-lams.

Loading Pattern

Specifies the manner in which the member is loaded. The choices correspond to the categories in NDS table 3.3.3.These are used in conjunction with the Beam Type to determine the effective length (le) for members in bending. Thisis also used to calculate the loading condition coefficient (KL) as a part of volume factor (CV) calculations for glu-lams.

Use Custom Length Between Inflection Points (Lbi)

This allows you to override the automatically calculated length between inflection points for the member. This length isused in calculating the volume factor (CV). It might be desirable to override this quantity if the true length betweeninflection points extends beyond the end of the member. In this case the length calculated will be too short (it onlylooks up until the end of the member). Also, if a value is manually specified it will apply for all locations on the member,whereas if the value is calculated automatically it is calculated separately for each point along the member length atwhich checks are made.

End Notch Type

Specifies the type of notches that are assumed to exist at critical shear location. Notches may be specified as either onthe tension or compression side of the beam. Refer to NDS 3.4.3.2 for the reductions in shear capacity at notchlocations. When notches are specified you must also specify the notch depth and possibly the offset "e" shown in Figure3E of the NDS. Note that the nominal depth of the notch, "dn", is calculated by taking the beam depth minus the notchdepth entered.

Deflections Parameters:

Deflection criteria are only available when a Member Type is specified as "Beam" or "Other". Deflections maybespecified in a variety of ways. Specified Deflections criteria does affect unity checks. You must also include "deflection"load combinations in the Load Case Manager to obtain deflection checks. More information is available on the DesignConcepts (Section 5.1.2).

Overrides Parameters

Nearly all of the C-Factors can be manually overridden in VisualAnalysis. The load duration factor is an exception (seeabove). There are situations where a particular factor can be difficult to apply in the design module. In theseinstances, factors are conservatively assumed as 1.0 (or as specified in the NDS). Certain factors may have no effectbecause they do not apply to the currently selected Design Member Type (from the 'General' parameters group). Notethat by overriding an adjustment factor you cause the overridden value to apply for checks made at every location onevery member for every load case. Some factors might otherwise have various different values calculated, so thinkcarefully before deciding to override a factor and double-check the results. If factors are overridden, it is up to you to



verify that the design stress values and member capacities meet code requirements. Overridden factors are appliedto all members in the Design Group.

Override COV?: Allows a custom value for the material COVE. Normally the program will use the values specified inTable F1, Appendix F of the NDS. This value is used in calculation of the beam stability factor (CL) and the columnstability factor (CP).

Fb Weak: The allowable bending stress for flexure (for Structural Composite Lumber) causing moment about themember's section y-axis.

Fv Weak: The allowable shear stress for shear (for Structural Composite Lumber) acting in the member's section z-axis.

Ft: The allowable stress for axial tension (Poles).

The allowable stresses for a given structural composite lumber section or group of sections are dependent onmanufacturer specific data. With this in mind, IES has created several Structural Composite Lumber material categorylocated within the main Wood material category. The materials contained in each category each have varyingproperties. If you find yourself using a particular material frequently, and the database values differ from what youprefer to use (some data base values are set at zero because no manufacturer values exist) you can go to the databaseand edit one of the existing materials or add a new material with customized (non-zero) allowable stress values forreuse on future projects.

Mat Override: Overide the NDS 4.1.3.3 limitation on using 'Beam and Stringer' materials with 'Post and Timber' sizedmember shapes. Use this option if your materials are properly graded.

Wood Reports

You can create a design report by double-clicking on a member in the Design View, or through the Report View.VisualAnalysis reports show the design parameters as well as 'controlling' checks. You can expand the report to show allof the checks that have been performed by double-clicking on the report and choosing the Complete Details option.

The notation used is similar to that used in the NDS code. Subscripts are not used in the design reports so Ft is writtensimply as Ft. Similarly, coefficients like CD are written as CD. In general, allowable stresses use an upper case F, suchas Fc for compression, Ft for tension, etc., while actual stresses use a lower case f. When you see "Ft/Fc" or "ft/fc" thatmeans the value in that column is either tension OR compression, not the ratio. The design reports have the sameformat whether the member is in tension or compression.

Report Details

The report begins with a Member Unity Checks table. This table basically provides a design summary listing whichmember is being reported and its extreme unity value.

Next, the report provides a table of load cases that were considered when doing member checks. This table associatesa load case number, referenced in the tables below, with the actual name of the load case. Note that the strength casesand serviceability cases are not numbered separately. Strength load cases are assigned numbers first and thenserviceability load cases receive numbers.

The report goes on to give a summary of the group's design parameters, including: size constraints, bracinginformation, deflection limits, and special wood parameters.

The last part of the report provides detailed information about the numbers involved in the code checks. The defaultreport (created by double-clicking on a member in the design view) lists only the extreme checks for the group. Ifdesired, there is an option to have the report display all of the information for every offset along each member of thegroup--simply double-click on the report and choose the Complete Details option. Note that a report for a three-dimensional structure will include weak axis checks for flexure, shear, and deflection. Also note that some columns intables (specifically in the combined check table) represent two possible values. These values are separated by a '/'symbol, which should not be interpreted as 'divide by' but rather as 'or'. The following summarizes the informationdisplayed in these tables:

All Tables



Member Name: The name of the member, as assigned in Model View.Load Case #: The load case used for this particular check. The actual name of this load case can be determined byconsulting the load case table above. Note that if the table you're looking at is a serviceability check (deflection) youshould be checking the service number column in the design load case table.

Offset: The point along the member at which this check was made, measured in length units (feet, inches etc.;whatever you've specified under Design | Visual Design Units) from the end of the member.

CD: Load duration factor.

CM: Wet service factor.

Ct: Temperature factor.

Greek Lambda (l): Time-effect factor (LRFD only)

Greek Phi (f): resistance factor (LRFD only)

Axial Check Table

State: Tension or compression

Ft/Fc: The unadjusted allowable stress value: Ft or Fc', depending on whether the member is in tension orcompression.

CF: Size factor. This factor does not apply to glued laminated timber members, so reports for members of that type(like the example report above) will not show the CF column.

CP: Column stability factor; only applies to compression checks.

Csp: Single pile factor per NDS section 6.3.12. For piles and poles only.

Cu: Untreated factor per NDS Table 6.3.5. For piles and poles only.

Ccs: Critical section factor per NDS equation 6.3-1. For piles and poles only.

Ft'/Fc': Adjusted allowable stress value; Ft' or Fc' depending on whether the member is in tension or compression.

ft/fc: Actual stress from analysis results. This number will always appear positive; the State column will indicate tensionor compression.

Unity Check: Ratio of actual stress (ft or fc) to allowable stress (Ft' or Fc').

Flexure Check Table

Fb: The unadjusted allowable bending stress.

CL: Beam stability factor. For glued laminated timber members, this value will read '> CV' if it's greater than the volumefactor, since only the lesser of these is to be used.

CF: Size factor. This factor does not apply to glued laminated timber members, so reports for members of that type(like the example report above) will not show the CF column.

CV: Volume factor. For glued laminated timber members only. The value will read '>=CL' if it's greater than or equal tothe beam stability factor, since only the lesser of these is to be used. For SCL Lumber, the Cv factor used is found inthe shape database.

Cfu: Flat use factor. This column is only displayed for weak axis flexure checks.

Cr: Repetitive member factor. This column is only displayed if the 'Repeat member' box was checked in the groupparameters dialog.

Cf: Form factor.

Csp: See Axial Check Table above.

Cu: See Axial Check Table above.



Fb': Adjusted allowable bending stress.

fb: Actual bending stress from analysis results.

Unity Check: Ratio of actual bending stress (fb) to allowable bending stress (Fb').

Shear Check Table

Fv: The unadjusted allowable shear stress.

CH: Shear stress factor. This column is only displayed if a shear stress factor was specified in the group parametersdialog.

Cu: See Axial Check Table above.

Fv': Adjusted allowable shear stress.

fv: Actual stress from analysis results. This value may include an increase due to notches.

Unity Check: Ratio of actual stress (fv) to allowable stress (Fv').

Deflection Check Table (will not appear if no deflection limits were specified)

dy: The deflection of the member with respect to the section y axis ('dz' for weak axis deflection checks).

Limit: The deflection limit specified in the group parameters dialog.

Unity Check: Ratio of the actual deflection to the deflection limit.

Combined Stresses Check Table

State: Tension or compression.

Ft'/Fc': Unadjusted allowable stress value: Ft' or Fc', depending on whether the member is in tension or compression.

Fb1*/FcE1: For members in tension, this column represents Fb1*. For members in compression, this column representsFcE1.

Fb2*/FcE2: For members in tension, this column represents Fb2*. For members in compression, this column representsFcE2.

Fb1**/Fb1': For members in tension, this column represents Fb1**; for members in compression, this columnrepresents the adjusted allowable bending stress in the strong direction.

Fb2**/Fb2': For members in tension, this column represents Fb2**; for members in compression, this columnrepresents the adjusted allowable bending stress in the strong direction.

FbE: For members in tension, this column is meaningless and will read '-NA-'; for members in compression, this columnrepresents FbE.

ft/fc: For members in tension, this column represents the actual tensile stress from the analysis (ft). For members incompression, this column represents the actual compressive stress from the analysis (fc).

fb1: For members in tension, this column is meaningless and will read '-NA-'; for members in compression, this columnrepresents the actual strong axis bending stress from the analysis results.

fb2: For members in tension, this column is meaningless and will read '-NA-'; for members in compression, this columnrepresents the actual weak axis bending stress from the analysis results.

Notes and Messages

Note that sometimes a table heading may be followed by the message "Nothing to check, or check was disabled". Thiswill happen when a check is meaningless for all members of a group. For example, if a group is made up of simplysupported beams with no axial force, the report will not include axial or combined stresses checks. The idea behind thisis to save calculation time and eliminate unneeded information in reports. This message can also appear when one or



more members of a group have a different member type than the group member type. For example if a design grouphas been designated as glued laminated timber but includes some dimension lumber members, it will not perform unitychecks on the dimension lumber members (it will still design them however, as glu-lams).

There are several messages that may occur indicating that a "Check was not performed". The "***Note:" section at theend of the report will provide specific information on why the check could not be performed. The most common note isthat the "shape and material are not consistent" along with a list of the material and shape currently being used. Inorder to get a unity value, the shape type must match the material. An example of an incorrect match would be to havea dimension lumber Design As shape category and a Design As material from the "Visually Graded Timber" category.

Wood References

1. American Forest and Paper Association, National Design Specification for Wood Construction. 2012 Edition.2. American Forest and Paper Association, National Design Specification for Wood Construction. 2005 Edition.3. Breyer, Donald E., Design of Wood Structures. Third Edition, McGraw Hill, Inc., 1993.

5.4 Steel DesignRequires: Design LevelVisualAnalysis checks and designs hot rolled steel members (beams, columns, braces, etc.) according to specificationslisted below.

AISC 360-10 ASD & LRFDAISC 360-05 ASD & LRFDCSA S16-14 LRFD

Composite beams (Section 5.8) can be checked using the AISC specifications. Please note that you must useappropriate load combinations (Section 9.1.2) (Strength for LRFD, Allowable for ASD) to obtain design checks.

Steel Assumptions and Limitations

Design Forces

All forces and moments are assumed to act about the principal axes of a member's cross-section. Similarly, shear loadsare assumed to pass through the shear center so that no torsional moments will be present in the results. Axial loadsare assumed to pass through the centroid of a member so that no moments are present in a first order analysis of anaxially loaded member. It is up to you to watch for and check any second-order effects or other conditions that violateassumptions made in the analysis or design.

Steel 'h' Approximation

AISC defines h as "the clear distance between flanges less the fillet or corner radius". If a shape is not in the shapedatabase or does not store the k dimension, then we assume h = D - 3*tf.

Span Length Assumptions

VisualAnalysis looks at a member-element's length to determine the span length which in turn affects unbracedlength. For a Combined Member this is the total length of the member, regardless of internal nodes or connectingelements. For members designed according to the AISC specifications, this might also effect the determination of Cb.For members designed according to CSA specifications, this might effect the determination of w2 and k.

If your member span is longer than the element span, you may want to use the Combined Member feature inVisualAnalysis to help make the design software smarter. Alternately, you can specify an unbraced length directly andoverride the calculated values for Cb.

Tapered Members



There is little support for tapered members: we check the member as if it were prismatic, using the start-end shape.

You could 'check' a tapered member by splitting it into many short prismatic pieces, and setting a larger unbracedlength on each section. This is not very practical as you need about 100 pieces to be as accurate as a single depth-tapered member using the built-in taper feature.

Custom Shapes

VisualAnalysis will not design or check built-up shapes (channels on wide flanges) or shapes that do not fall into thenormal AISC or CSA categories (W, HSS, 2L, etc.). There are also limits on member dimensions. Deep beams (plategirders) are not checked for example. For unusual shapes, you can use the stress check (Section 5.5) feature to getpreliminary checks from VisualAnalysis. You can also use IES ShapeBuilder to get stress distributions on more complexshapes.

CSA Limitations

Due to a lack of specific information in the CSA manual, bending checks for Tee and Angle sections are carried outaccording to the AISC LRFD Specification requirements. Class 4 shapes are not supported with the "steel" designgroups, you can use the AISI Cold-formed steel design for any thin-walled/cold-formed shapes. Also the AISC definitionfor Cb is used in place of the w2(omega) used in the CSA, with a 2.5 limit.

AISC 2005 Limitations

Equation G6-2a, using Lv for a shear check is not evaluated, G6-2b is used always. This is conservative.

Steel Capabilities

Shape Types

VisualAnalysis will check and design AISC and CSA shapes in the IES Shape Database, along with any shape in theshape database that supports one of the 'property sets' required by steel design. This allows British Steel shapes in theIES Shape Database to be supported, but only for AISC or CSA checks. There is no support for non-AISC/CSAspecifications or codes. You may customize the IES Shape Database to include whole libraries of custom, foreign, orlegacy shapes. Use IES ShapeBuilder to customize the IES Shape Database.

In addition to the database shapes, VisualAnalysis will check the Standard Parametric shapes created directly inVisualAnalysis. These include: rectangles, squares, I-beams, channels, tees, single angles, round and pipe sections andzees.

Composite beam design is tested for Wide Flange or I-Beam type shapes only, though other shapes may check OK.

Member Forces

VisualAnalysiss designs members for axial forces, shears, bending moments, torsional moments, and deflections.Checks are automatically made whenever a demand is present in the results. Where appropriate, both the strong andweak axes of the member are checked in addition to any interaction requirements.

All member forces are with respect to the member element's local axes, which are assumed principal. For asymmetricshapes these axes won't align with the geometric axes.

Seismic Compactness

Member elements can be checked against the seismically compact classification set forth in AISC's Seismic Provisions.The classification depends on the type of lateral-force-resisting system being used and the type of forces present in themember. The user must decide if a particular member is required to be seismically compact.

Torsion Design

Design Specification



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All torsion checks are based on the provisions of AISC. The Canadian steel code (CSA) does not provide specificrequirements for torsion design (see CSA section 14.10). The general requirements given in CSA are satisfied using themore detailed requirements given in AISC 360 and AISC Design Guide 9

Torsion Check Types

The following limit states are checked in VisualAnalysis during the torsion design process:

1. Torsional shear stresses are compared to the capacities from AISC equations H3-1 through H3-5 for closedshapes and from AISC equation H3-8 for open shapes.

2. Torsional normal stresses are compared to the capacity from AISC equation H3-7.3. Combined Stresses with Torsion are evaluated using the equations described below.

The limit state described by AISC equation H3-9 is not checked as there is no guidance for calculating Fcr in thespecification.

Torsion Design Levels

VisualAnalysis provides two levels of torsion design.

1. Limited Torsion Design - When shapes with an open cross-section are twisted they tend to warp. If such amember is designed in VisualAnalysis without specifying idealized torsional boundary conditions warping isneglected. When warping is neglected the entire torsional moment is assumed to be resisted by uniform or SaintVenant shear stresses. Neglecting warping can result in incorrectly low unity values in some cases and incorrectlyhigh unity values in others. If the limited torsion design is used for a member subject to warping, design done byVisualAnalysis is incomplete. The complete design would need to be done outside of the software.

2. Advanced Torsion Design - The advanced torsion analysis uses a numerical solution process to solve thedifferential equation associated with warping (see AISC's Design Guide #9 for a summary of torsion theory). Thesolution is based on idealized boundary conditions provided by the user, and the internal torsion distributioncalculated during the finite element analysis. The solution determines the angle of rotation along the length ofthe member and the first two derivatives of the rotation. Using this information warping normal stresses,warping shear stresses, and uniform shear stress can be calculated for a given shape. Advanced torsion design isbased on warping section properties for shape types (i.e. I-Beam or Channel) these calculated section propertiesmay differ from published values. Advanced torsion design is only available in the advanced level ofVisualAnalysis.

When closed shapes are designed, limited and advanced torsion processes will produce similar results. While AISC onlyexplicitly requires the combination of shear and normal stresses for HSS cross-sections, VisualAnalysis conservativelycalculates them for all cross sections--even though they are unlikely to control--because it makes sense to do so from amechanics viewpoint.

Torsion Boundary Conditions

Torsion Boundary Conditions are idealized as one of the following during design in VisualAnalysis.



The options listed above are idealized boundary conditions. Boundary conditions between these options cannot beconsidered in VisualAnalysis. Furthermore, the idealized boundary condition used for design may conflict with theboundary condition used during analysis. For example one member's twisting support may be provided by the bendingstiffness of another member it frames into. In this scenario, twisting is restrained at the end and torsional moments candevelop, but the rotation may still be greater than zero at the end. If during design the ends of the beam are idealizedas torsionally pinned the design software will force the rotation at the ends to be zero when solving the differentialequation. Sound engineering judgment must be used when selecting the appropriate boundary conditions. In somecases none of the idealized boundary conditions provided by VisualAnalysis will be appropriate, and the design will needto be completed outside of the software.

Stress Superposition

When combining stresses for torsion design, VisualAnalysis conservatively combines the maximum stresses regardlessof where they occur on the cross-section. This results in conservative unity values, but is not unreasonably conservativefor most shapes and loadings.

Combined Forces with Torsion

VisualAnalysis uses the following two equations to calculate unity values for the interaction of torsion with flexure andaxial forces.

"sv" denotes Saint Venant's stress

"w" denotes a stress from warping

Fn,sv = 0.6*Fy for open shapes and is defined by AISC H3 for closed shapes.

Fn,w = 0.6*Fy

fT = 0.9

The equation shown above is in LRFD form, the ASD version is similar.



The combined equations are based on AISC H3-6 and Design Guide #9 section 4.7. Combining the demands in themanner shown allows both open and closed cross sections to be checked with the same interaction equation. The AISCspecification does not explicitly dictate how demands should be combined with torsion for open shapes.

The equation used to check combined stresses with torsion is more conservative than the combined equations for axialand bending found in sections H1 and H2 of AISC. Because of this AISC does not require the combined equation withtorsion to be checked unless the torsion unity by itself is greater than 0.20. In VisualAnalysis a similar threshold of 0.10is used for open shapes.

Twisting Stiffness: Analysis vs. Design

The finite element formulation for beams in VisualAnalysis does not consider warping. Warping actually has a significantimpact on a beam element's twisting stiffness. Because of this, the rotations calculated during the advanced torsiondesign process might vary significantly from the rotations calculated during the finite element analysis.

The advanced torsion design process uses the internal torsion distribution calculated during the finite element analysis.For an indeterminate problem, this distribution may have been different if warping stiffness had been considered duringthe finite element analysis. In light of this, the advanced torsion design may be performed using a torsion distributionthat is incompatible with the more accurate torsional stiffness used in the design calculations. Judgment is needed todetermine when the incompatibility is significant or unconservative.

Segmented Members

Torsion boundary conditions are applied at the end of each member element. As a result, segmented members must becombined before the advanced torsion design will work. The software will not stop you from designing a chain ofindividual member elements. However each element will be designed on its own and the torsion boundary conditionswill be applied at the interior nodes; as a result the design results will be completely wrong.

Steel Parameters

Note: All of the parameters described below are edited/selected on the Modify Tab of the Project Manager while inthe Design View.Specification: Choose between ASD and LRFD code provisions.

Overstrength: Designs member for higher seismic forces based on user specified Overstrength factors and IBCSeismic Design Category.

Seismic Compactness: Choose weather a member should be checked for seismic compactness, and the type oflateral-force-resisting system.

Shape Category: Chooses shape category from which the VisualAnalysis "Design" feature selects shapes to optimizedesign.

Disable Checks: Prevents design checks from being performed on the selected design group. Allows you to speed updesign checks and focus on targeted areas of larger models.

Bracing Parameters:

By default, member unbraced length is assumed to be the member-element length between nodes. See Bracing inVisualAnalysis (Section 5.1.2) for a complete description of bracing member elements for design checks. The lateraltop/bottom unbraced length is used for Chapter F flexure checks. Strong unbraced length is used for Chapter Ecompression checks.

Deflections Parameters:

Deflections may be specified in a variety of ways. Specified Deflections criteria does affect unity checks. You must alsoinclude "deflection" load combinations in the Load Case Manager to obtain deflection checks. More information isavailable on the Design Concepts (Section 5.1.2).



Axial Parameters:

See Design Parameters (Section 5.1.2).

Constraints Parameters:

Options under this heading allow you to specify depth and width limitations on the members chosen when theVisualAnalysis "Design" feature selects shapes to optimize design.

Overrides Parameters:Overrides Require: Advanced LevelCb: This option allows you to override the AISC bending coefficient.

Steel Report Options

The steel design report includes a number of optional components. You may control what information is included bydouble-clicking on the report after it is generated. By default the report echoes the design parameters and showsonly the controlling checks for each member and load case. If you wish to investigate results further, you may expandthe report to show every check made at every offset of every member in every load case.

Steel Report Organization

Reports have two primary parts: Parameters and Checks. The parameter section presents the information you enteredin the parameters dialog. It is grouped and formatted for easy reading. If the group has a valid design shape, there willbe some additional information about that shape attached to the end of the parameter section. (If the group does nothave a valid design each member might be a different shape, so details about the shape are not reported.)

Checks are organized in the form of tables. The layout of columns in a typical report table is as follows:

ColumnName

Description

Name The member's name as in VisualAnalysis

Section Only in member reports, the cross section (e.g. W8x10).

LoadCombination

Forces and stresses are obtained from strength load cases while deflection checks utilize the servicecase numbers. A load case may have both a strength number AND a serviceability number, that maydiffer.

Offset This is the distance from the 'start' end of the member. The number and locations of offsets are asdefined in the performance settings in VisualAnalysis

Demand,Capacity

These columns vary depending on the type of check, but they represent code stipulated values. Inmost cases these are used directly in the unity check, but there are some special cases where theunity checks also include intermediate values, or values not reported.

CodeReference

The controlling equations or provisions from the specification. For example, "F1-8" refers to thisequation number in the ASD or LRFD manual. A code reference like "AE3-3" refers to equation (A-E3-3) in Appendix E of the manual. Sometimes there are additional references given, like "AB5-6" toindicate a reduction for slender compression elements (Q < 1).

Unity Ratio The unity check value for this particular member, load case, and offset. Unity checks are calculated asthe absolute value of an actual stress divided by an allowable stress [ASD] or as the ultimate force(factored) divided by [F x (the nominal force)] [LRFD]. Check values of less than 0.005 are notreported to help reduce report size.

Details Intermediate values and other information to help you validate or run a manual check.

Steel Report Notation



The steel reports attempt to use a notation similar to that used in the ASD and LRFD specifications. We have not usedsubscripts however, so a parameter that appears as Lr in the specification will appear as simply Lr in a VisualAnalysisreport. The other major difference in notation is the use of section axes coordinates z and y in place of the AISCcoordinates x and y.

Accordingly: fa, fb, fv are actual axial, bending and shear stresses, respectively. Similarly, Fa, Fb, Fv represent allowableaxial, bending and shear stresses, respectively. P is an axial force, M is a moment and V is a shear.

Greek characters are used in the LRFD reports, using the Symbol font installed on most Windows systems. Where this isnot possible (dialog boxes and other on-screen controls), the Greek characters are spelled out: phi, lambda, etc.

Steel Report Notes and Warnings

By default, a given check table will only display the worst-case unity check for a given member and load case. You mayview the complete set of checks by clicking on the table and choosing Table Properties from the context menu. Thenmake adjustments in the dialog.

In some cases there will be notes and or warnings displayed either in a check table or at the bottom of the report.These are designed to be self-explanatory.

Steel References

VisualAnalysis was written to conform to the following specifications:

1. Specification for Structural Steel Buildings, ANSI/AISC 360-10, June 22, 2010, American Institute of SteelConstruction (AISC).

2. Specification for Structural Steel Buildings, ANSI/AISC 360-05, March 9, 2005, American Institute of SteelConstruction (AISC).

3. CSA S16-14 Design of Steel Structures, CSA Group, June 2014, ISBN 978-1-77139-355-3.

Additional References:

1. Manual of Steel Construction, 14th Edition, 2010, AISC.2. Manual of Steel Construction, 13th Edition, 2005, AISC.3. Manual of Steel Construction, Load & Resistance Factor Design, Volume 1, Structural Members, Specifications &

Codes, 2nd Edition, 1994, AISC.4. Flexural Strength of WT Sections", Duane S. Ellifritt, et. Al., AISC Engineering Journal, 2nd Qtr 1992. pp. 67-74.

(With special thanks to Mr. Blake Haley for his kind assistance with WT design.)5. Design Strength of Concentrically Loaded Single Angle Struts", A. Zurieck, AISC Engineering Journal, 1st Qtr

1993. pp. 17-21.6. Steel Structures: Design and Behavior, Emphasizing Load and Resistance Factor Design, 4th Edition., Charles

Salmon & E. Johnson, Harper Collins College Publishers, 1996.7. Design of Steel Structures, 3rd Edition, Edwin Henry Gaylord, et. Al., McGraw-Hill, Inc., 1992.8. Steel Design Handbook: LRFD Method, Akbar R. Tamboli, editor, McGraw-Hill, Inc., 1997.

5.5 Generic Stress and Deflection ChecksRequires: Advanced LevelVisualAnalysis can check stress and deflections (Section 5.1.2) levels in members of any material or shapeaccording to limits you define. This feature is provided to help you check members that VisualAnalysis could not checkusing AISC, NDS, ACI, ADM or AISI, as those kinds of checks are more sophisticated and accurate.

You might also use this feature for fast preliminary checks. You can perform stress checks for axial, bending orcombined stress limits you define. Limits may be different for tensile or compressive stresses. The stresses calculatedby VisualAnalysis are based on the design load cases (ASD or LRFD). Deflections are checked against any specifieddeflection load combinations.



Generic Capabilities

This type of check may be performed on tapered as well as prismatic members. Custom member shapes or specializedmaterials may be checked using this feature.

Auto-Stress Groups

If your shapes could get checked by other design modules, and you would rather use this faster, lighter check method,you might want to turn of the Auto-Group Members feature so that generic groups are created instead. To enable ordisable generic design groups, change the Project Setting for Auto-Stress Checks.

Generic Limitations

Design Forces

All forces and moments are assumed to act about the principal axes of the member's cross-section. Shear forces andtorsional moments are simply ignored by this tool.

Design Stresses

All stresses are based on the member's section z (strong) and y (weak) axes. Axial stress is defined as the average:axial force divided by cross sectional area. Bending stress is defined at the 'extreme fiber' as: the moment divided bythe member's section modulus to the extreme fiber.

Combined Stresses

The locations of combined stress-checks on the cross section are typically the four extreme corners, but some shapesadjust these locations as shown in the picture below. For round shapes, the combined checks are at the top & bottomhorizontal-center, and left & right vertical-center, rather than the four corners. meaning the bending from strong andweak axes are not combined directly. Tee shapes are also adjusted. Combined checks will simply fail on single angles,spandrels or zee shapes because the 'corners' don't exist! We recommend using IES ShapeBuilder (Section 2.2) fordetailed investigation of stresses in complex cross sections.

Generic Parameters

Deflection Limit Options

See deflection limits (Section 5.1.2) in the essentials topic, as deflection checks are common among all materialtypes.

Stress Limit Options

The Axial?, Strong Bending?, Weak Bending?, and Combined? fields allow setting of one of four options forchecks of axial force stress, bending stresses from moments about the section-z axis, bending stresses from momentsabout the section-y axis, and combined axial stress plus both axis bending stress respectively. You may specify differentlimits for tension and compression for each type.

Hint: Positive numbers should be entered for your limits even though the VisualAnalysis sign convention uses negativevalues for compression forces and stresses. Using a very large limit effectively eliminates the check.



Generic Design Reports

Double-click on a member in a Design View to get a detailed report of exactly what was checked for a member (or allthe members in a group).

5.6 Aluminum DesignRequires: Design LevelVisualAnalysis designs aluminum members according to the Aluminum Design Manual (ADM) produced by the AluminumAssociation. Design checks per chapters A, B, D, E, F, G & H are provided for standard sections (found in Part V of theADM 2010) and Parametric shapes (Section 2.4) (rectangular, solid round, plates, etc.) are supported. Checks areperformed according to either of the following specifications:

ADM ASD 2010ADM LRFD 2010

Please note that you must use appropriate load combinations (Section 9.1.2) (Strength for LRFD, Allowable forASD) to obtain design checks.

Aluminum Assumptions and Limitations

Design Forces

All forces and moments are assumed to act about the principal axes of a member's cross-section. Similarly, shear loadsare assumed to pass through the shear center so that no torsional moments will be present in the results. Axial loadsare assumed to pass through the centroid of a member so that no moments are present in a first order analysis of anaxially loaded member. Because of these assumptions that are made in the software, it is up to you to watch for andcheck any second-order effects or other conditions that violate assumptions made in the analysis or design.

Span Length Assumptions

VisualAnalysis looks at member-elements to determine the span length which in turn affects unbraced length. Formembers designed according to the ADM specifications, this might also effect the determination of Cb. If your memberspan is longer than the element span, you may want to use the Combined Member feature in VisualAnalysis to helpmake the design software smarter. Alternately, you can specify an unbraced length directly and also override thecalculated values for Cb.

Tapered Members

There is little support for tapered members: we check the member as if it were prismatic, using the start-end shape.

You could 'check' a tapered member by splitting it into many short prismatic pieces, and setting a larger unbracedlength on each section. This is not very practical as you need about 100 pieces to be as accurate as a single depth-tapered member using the built-in taper feature.

Custom Shapes

VisualAnalysis will not design or check built-up shapes (channels on wide flanges) or shapes that do not fall into thenormal ADM profile categories (I, C, Z, L, etc.). Custom extrusions or other complex shapes are not supported. Thereare also limits on member dimensions: deep beams (plate girders) are not checked for example.

Deflection Checks

Deflection checks are made using the gross-section of the shape, no reduction is taken for effective widths according toADM L.3.

ADM 2010 Code Notes/Limitations



1. Stability requirements of Chapter C are not implemented.2. The entire cross section of members specified as "Heat Affected" (welded) is assumed to be affected. Reduced

stress values are used for all limit states.3. G.2 is assumed to provide Fs for one edge supported shear (weak axis in most cases) as well as both edges

supported. B is assumed to be clear distance from face of web to tip of flange.4. Solid shapes are assumed to have Fs = Fsy. Mechanics equations 3V/2A, 4V/3A are used for stress calculations.5. Pipe Shape shear strength is based on Equation G.3-2 with the Lv parameter taken as the entire member

length. This is conservative.6. B.5.4.1 Local Buckling strength for singly symmetric sections is based on elastic buckling strength. The allowed

increase for Post buckling of singly symmetric sections buckling globally about the strong axis is not utilized.7. Code provisions for Torsional and Flexural-Torsional Buckling (E.3.2) are applied to all shapes because no

exceptions are made. This leads to smaller capacities than if this provision is omitted such as in ADM2010 PartVII-18 Example 9 ( I-Beam in Axial Compression ).

8. The provisions of ADM2010 F.8 are implemented using the weighted average flexural strength per section F.8.3.9. F.2.1 For doubly symmetric sections, rye = ry as allowed in section F.2.1. Per ADM 2010, page II-25: “Section

F.2.1 gives very conservative results for certain conditions, namely for values of Lb/ry exceeding about 50, andfor beams with transverse loads applied in a direction away from the beam’s shear center.”

10. Single angles are always assumed to be bent about principal axes. Local buckling checks are made per F.5. a)(1). Local buckling checks per F.5.a) (2) (the case of an angle leg in uniform compression bent about thegeometric axes) is not covered.

11. A conservative view of chapter H section 3 is taken: we assume that the maximum flexural shear stress, normalbending stress, and torsional shear stress all occur at the same point on the cross section and that these can allbe superimposed with the axial stress. They are combined per interaction equations H.3-1 thru H.3-4.

12. Torsion is checked per chapter H.2 and H.3. These checks are limited to closed shapes and solid rods (roundsections). These shapes are not subject to warping stresses. Open shapes are not checked for torsionalcapacity as no code provisions exist. Open shapes are subject to warping stresses due to torsion. Open shapesmust be checked independently for torsional capacity and potential warping stresses.

Aluminum Capabilities

Shape Types

VisualAnalysis was created to check and design ADM standard shapes in the IES Shape Database. Any shape (or shapecategory) in the shape database that supports one of the 'property sets' required by Aluminum design can be checkedby this software as well. In addition to the database shapes, VisualAnalysis will design the Standard parametric shapescreated directly in VisualAnalysis . These include: rectangles, squares, rectangular tubes, I-beams, channels, tees,single angles, zees, round, pipe sections. Spandrels are not supported, but the equivalent section can be created with asingle angle.

Member Forces

VisualAnalysis looks at axial force, shear, flexure and deflections. Checks are automatically made whenever a force ispresent in the results. Where appropriate, both the strong and weak axes of the member are checked in addition to anyinteraction requirements. A St. Venant torsional shear stress is calculated from the torsional moment and added to theshear stress calculated in VisualAnalysis. No provision is made for warping stresses of any kind, which means that crosssections that are not "closed shapes" are not fully checked if torsion is present. The maximum torsional moment isreported at the bottom of the design report to help you remember this and to check for other torsional stresses thatmay be present.

Aluminum Parameters

Note: All of the parameters described below are edited/selected on the Modify Tab of the Project Manager while inthe Design View.



Aluminum Parameters:

Specification: Choose between ASD and LRFD code provisions.

Structure Type: Choose between Building and Bridge type structures (affects resistance and safety factors (Φ and Ω).

Member Type: Selects general member type, changing the selection of user input parameters. By default, these areset based on member orientation in the model (i.e. Beam-horizontal, Column-Vertical)

Overstrength: Designs member for higher seismic forces based on user specified Overstrength factors and IBCSeismic Design Category.

Shape Category: Chooses shape category from which the VisualAnalysis "Design" feature selects shapes to optimizedesign.

Disable Checks: Prevents design checks from being performed on the selected design group. Allows you to speed updesign checks and focus on targeted areas of larger models.

Heat Affected: Specifies that a member is Heat or Weld affected. Specify the % of member length at each end toconsider the welded material properties. Design checks are performed with Ftyw, Ftuw, Fcyw, Fsuw stress values in theheat affected zones.

Bracing

Member Bracing - By default, member unbraced length is the equal to the member length between nodes. SeeBracing in VisualAnalysis (Section 5.1.2) for a complete description of bracing member elements for designchecks.

Deflection Limits

Deflection criteria are only available when a Member Type is specified as "Beam" or "Other". Deflections maybespecified in a variety of ways. Specified Deflections criteria does affect unity checks. You must also include "deflection"load combinations in the Load Case Manager to obtain deflection checks. More information is available on the DesignConcepts (Section 5.1.2)..

Axial / Column

Specify parameters for effective lengths. See the common Design Parameters (Section 5.1.2).

Size Constraints

Specify size limits on member shapes. See the common Design Parameters (Section 5.1.2).

OverridesOverrides Require: Advanced LevelFty, Ftu, Fcy, Fsu: This option allows you to ADM stress parameters used for unity checks and design. The value ofFsy will be affected by Fty. These overrides only affect design if the 'Heat Affected? check box is not selected (i.e. nopart of the member is Welded).

Ftyw, Ftuw, Fcyw, Fsuw: This option allows you to ADM stress parameters for weld affected sections used for unitychecks and design. The value of Fsyw will be affected by Ftyw. These overrides only affect design if the 'Heat Affected?check box is selected.

Cb: This option allows you to override the ADM bending coefficient.

Aluminum Report Options

The Aluminum design report includes a number of optional components. You may control what information is includedby double-clicking on the report after it is generated. By default the report echoes the design parameters and showsonly the controlling checks for each member and load case.



Aluminum Report Organization

Reports have two primary parts: Input Parameters and Checks. The parameter section presents the information youentered in the parameters dialog. It is grouped and formatted for easy reading. If the group has a valid design shape,there will be some additional information about that shape attached to the end of the parameter section. (If the groupdoes not have a valid design each member might be a different shape, so details about the shape are not reported.)

Checks are organized in the form of tables. The layout of columns in a typical report table is as follows:

Column Name DescriptionMember Name The member's name as in VisualAnalysis.Member Section Only in member reports, the cross section (e.g. W8x10).Load Case # Load cases are listed by number in design reports. The numbers are keyed to the table

included at the top of the design report. Refer to the table under "Design Group Results" or"Design Member Results". Forces and stresses are obtained from strength load cases whiledeflection checks utilize the service case numbers. A load case may have both a strengthnumber AND a serviceability number, that may differ.

Offset This is the distance from the 'start' end of the member. The number and locations of offsetsare as defined in the performance settings in VisualAnalysis

Actual Forces,Stresses,IntermediateCalculations

These values can be traced back directly to analysis results.

Allowable Stresses,Nominal Forces

These columns vary depending on the type of check, but they represent code stipulatedvalues. In most cases these are used directly in the unity check, but there are some specialcases where the unity checks also include intermediate values, or values not reported.

Code Reference The controlling equations or provisions from the specification. For example, "F1-8" refers tothis equation number in the ASD or LRFD manual. A code reference like "AE3-3" refers toequation (A-E3-3) in Appendix E of the manual. Sometimes there are additional referencesgiven, like ", AB5-6" to indicate a reduction for slender compression elements (Q < 1).

Unity Check The unity check value for this particular member, load case, and offset. Unity checks arecalculated as the absolute value of an actual stress divided by an allowable stress [ASD] or asthe ultimate force (factored) divided by [F x (the nominal force)] [LRFD].

Aluminum Report Notation

The Aluminum reports attempt to use a notation similar to that used in the ASD and LRFD specifications. We have notused subscripts however, so a parameter that appears as Lr in the specification will appear as simply Lr in aVisualAnalysis report. The other major difference in notation is the use of section axes coordinates z and y in place ofthe ADM coordinates x and y.

Accordingly: fa, fb, fv are actual axial, bending and shear stresses, respectively. Similarly, Fa, Fb, Fv represent allowableaxial, bending and shear stresses, respectively. P is an axial force, M is a moment and V is a shear.

Greek characters are used in the LRFD reports, using the Symbol font installed on most Windows systems. Where this isnot possible (dialog boxes and other on-screen controls), the Greek characters are spelled out: phi, lambda, etc.

Aluminum Report Notes and Warnings

By default, a given check table will only display the worst-case unity check for a given member and load case. You mayview the complete set of checks by clicking on the table and choosing Table Properties from the context menu. Thenmake adjustments in the dialog.

In some cases there will be notes and or warnings displayed either in a check table or at the bottom of the report.



These are designed to be self-explanatory.

Aluminum References

VisualAnalysis was written to conform to the following specifications:

1. Specification for Aluminum Structures, 2010 Aluminum Design Manual (ADM). The Aluminum Association, ISBN978-0-9826308-0-8

Additional References:

1. Aluminum Structures, Second Edition, J.R. Kissel & R.L.Ferry, John Wiley & Sons, Inc.2002

5.7 ColdFormed Steel DesignRequires: Design LevelVisualAnalysis designs light-gauge cold-formed steel members used for beams, columns, braces, wall components,headers, etc. VisualAnalysis cold-formed design checks are performed with a built-in, specially licensed version of theCFS 10.0 program from RSG Software. Checks are performed according to one of these specifications:

2016 NAS/AISI (ASD and LRFD)2016 NAS/Mexico (ASD and LRFD)2016 NAS/Canada LSD 2012 NAS/AISI (ASD and LRFD)2012 NAS/Mexico (ASD and LRFD)2012 NAS/Canada LSD2010 NAS/AISI USA (ASD and LRFD)2010 NAS/AISI Mexico (ASD and LRFD)2010 NAS/AISI Canada (LSD)

Other capabilities:

Shapes are chosen from a database from several manufacturers.Optional inclusion of cold work of forming effects.Provides flexible bracing options.Custom cold-formed shapes (see below)

Assumptions and Limitations

Carbon steel materials are assumed to comply with the 'Applicable Steels' listed in the AISI designspecification. E = 29,500 ksi during design checks!The effects of holes are ignored for shear strength calculations.Design checks assume there are no shear stiffeners.Lateral braces are assumed to comply with AISI requirements.For sections that have web holes, the holes are assumed to be circular.For elements with holes under a stress gradient, the effective width is determined by treating the elementsadjacent to the hole as unstiffened elements.When a member is used as part of a stud wall system, the design check does not include the strengthcontribution of the sheathing.Web-crippling checks are not performed.Connections are not designed or checked.Checks are limited to shapes found in the IES Shape Database that are also associated with a '.scl' shapelibrary file. See also: Cold-Form Customizations



Currently there is no way to "double-up" members. You may either model and check the membersindependently, or you will need to provide custom member shapes for the IES shape database.For 2010 specifications, Lm (distortional brace length) is conservatively assumed to be 240 inches, there is noway to set it in VisualAnalysis, you would need to check in CFS directly to use a different value.There is currently no support for stainless steel design (ASCE 8) in VisualAnalysis even though the CFSprogram has this feature.

Design Parameters

When you create a Design Group for cold-formed steel design, you need to specify the design parameters that willcontrol the unity checks and design of members. These parameters are available in the Project Manager under theModify tab. Cold-form parameters include the group name, bracing, size constraints, and shape category. In addition,there are parameters that are specific to cold-formed steel.

Effective Length Factors

The effective length for buckling about each axis will vary depending upon member end conditions and will becalculated automatically. Effective length factors can be manually specified if desired. Kz is for buckling about thestrong axis, Ky is for buckling about the weak axis, The subscripts refer to the member element's section-coordinatesystem, where x is the longitudinal axis, z is the strong bending axis, and y the weak bending axis. These parametersare ignored if there is no axial force in the member.

Bending Coefficients

Cb factors are calculated automatically, but may be overridden. Note that VisualAnalysis calculates these coefficientsbased on the moments on a single member element, so if the physical beams or columns are broken into severalelements the Cb factors may not be calculated correctly. The length of your member, and the results over this lengthare used in the calculation, so splitting members may give different results.

Moment Coefficients

Moment magnification factors depend on the stiffness of the frame and the end moments on the member. These Cmfactors are calculated automatically, but can be overridden here.

Moment Reduction Factor

This is required by the code in some situations. See AISI code section C3.1.3. The value must be greater than or equalto zero and less than 1.0. There are also times when it does not apply, in which case this option will be grayed out.Note that unsymmetrical sections, such as eave struts, require continuous bracing in all directions to be properlydesigned.

Strength Increase for Cold-Working

You may optionally use of higher material strength values due to the strain hardening that occurs in steel during thecold-working process.

Member Bracing

By default, member unbraced length is the equal to the member length between nodes. See Bracing inVisualAnalysis (Section 5.1.2) for a complete description of bracing member elements for design checks.

Torsional Bracing

Torsional unbraced length defaults to the larger (less conservative) of the top and bottom flange unbraced length. Theidea here is that a lateral brace also restrains twisting of the cross section.



Reports

Double-click on a member in the Design View to get a detailed report of the checks that were made. Report columnheadings are described below:

Member Name The name of the member being checked.

Load Case # The index of the load case from which the analysis results used in making the check were obtained.There is a table at the top of design reports which associates load case indices with the actual name of the load case.

Offset The location along the member length at which this check was made.

Unity Check The ratio of applied to allowable load for this check. A check value greater than one indicates failure.

Notes One or more flags indicating that there is extra information regarding the check. The particular informationassociated with a given flag is shown in the "Notes" section below.

The checks correspond to code provisions as shown below:

Combined axial & bending check – Equation 1

ASD Tension/Bending AISI C5.1.1-1

ASD Compression/Bending AISI C5.2.1-1

LRFD Tension/Bending AISI C5.1.2-1

LRFD Compression/Bending AISI C5.2.2-1

Combined axial & bending check – Equation 2

ASD Tension/Bending AISI C5.1.1-2

ASD Compression/Bending AISI C5.2.1-2

LRFD Tension/Bending AISI C5.1.2-2

LRFD Compression/Bending AISI C5.2.2-2

Combined shear & bending check

ASD AISI C3.3.1-1

LRFD AISI C3.3.2-1

Notes

The report may include warnings, errors, or just notes about special conditions that were observed during the checks.

Custom Cold-Formed Shapes

It is possible to use VisualAnalysis for the design of custom cold formed shapes, or for designing shapes that were notoriginally included in the IES Shape Database. You will need to have the shapes defined in a .scl file, which is a shapelibrary file produced by the CFS program from RSG Software (www.rsgsoftware.com). The .scl file you create or obtainmay be imported directly into the database using the IES ShapeBuilder. These custom shape files need to be stored inspecific locations with other IES data (Section 1.7) on your machine in order for VisualAnalysis to find them and usethem.

References

1. American Iron and Steel Institute, Cold-Formed Steel Design Manual, various editions.2. RSG Software, Inc., 2803 NW Chipman Road, Lee's Summit, MO 64081. Mr. Bob Glauz, owner. IES licenses the

CFS 'engine' from RSG Software for cold-form checks. The full CFS product is available for purchase for moreadvanced uses such as creating .scl files for new shapes to be added to the database. Contact RSG at www.rsgsoftware.com or 816-524-5596.



http://www.rsgsoftware.com/

https://www.iesweb.com/products/shapebuilder/


5.8 Composite Steel Beam DesignComposite steel beam design is based on steel design (Section 5.4), sharing many features, assumptions,parameters, and limits, but is specific to beams with a slab on top.

Composite Beam design requires member elements to be in a steel design group. Once the steel design group iscreated, the option to design as composite beam is an available design group parameter in the Modify tab. Because ofthe way composite shape properties are calculated, you should only group together members that have the samemodel-shape and length.

Modeling for Composite Beams

When creating your structural model you simply use the steel shape for members. You may or may not want to modelthe slab using plates or meshed areas. Either way you need to account for the weight of the slab during analysis. Youmight want to account for the diaphragm stiffness if you are not modeling the slab explicitly, but that is a judgmentbased on your structure and requirements.

Composite Beam Construction Self-Weight Loads

In the design of unshored composite beams, there are typically two situations that must be considered. The first is thestrength of the steel beam alone, acting under construction loads that include the wet concrete slab weight. The secondis the full composite beam acting under design loads typical of all steel members.

Of course, if you choose a shored construction procedure, then construction loads do not apply and no steel-only checkis performed.

VisualAnalysis will automatically estimate self-weight construction loads for unshored construction. It uses only theself-weight of the steel and concrete slab as a simple steel-only check. Currently there is no way to specify specificconstruction loads or load cases for additional steel-only checks. If you have high construction loads, you will need tocheck the beam manually for these conditions.

Composite Beam Deflections

When designing composite beams there are typically two distinct deflections that are of concern. The first isconstruction deflection of the steel beam alone, and the second is the deflection of the composite section afterconstruction under service loads.

VisualAnalysis makes no provision for limiting or calculating deflections of the first kind. It is assumed that thedeflection values can be readily obtained using construction loads for analysis. Furthermore, the beam is generallycambered to handle this deflection. As with stress calculations, construction deflections play no part if the beam isconstructed using a shored procedure.

VisualAnalysis does allow you to limit the service load deflections of the fully composite beam. It also estimates thesedeflections by scaling the reported deflections by the ratio of the steel moment of inertia to the composite moment ofinertia. This check is performed for all serviceability load cases.

Composite Beam Bracing

Bracing for composite beams is assumed to be continuous for the top flange (metal deck or formwork) and the fullmember length for the bottom flange. Bracing differing from these defaults cannot be specified. If you want a differentbottom bracing, you could split the member in the Model View to effectively create shorter elements. See Bracing inVisualAnalysis (Section 5.1.2) for a complete description of bracing member elements for design checks.

Composite Beam Parameters

Composite Design Shapes

For composite beam design a reduced shape list is available. For AISC shapes this list is: W, M, S, HP, C, MC, and TS or



HSS (square and rectangular). If you are using other database shapes or parametric shapes you will be restricted tothose that use the same basic 'property sets' as the AISC shapes listed here.

Composite shapes are generally modeled for analysis using just the steel section. You may choose to model the slabwith plate elements in your model, but these elements are not affected by, nor do they directly affect the designsoftware, which will look only at the member element and its forces. There is no built-in way to model composite beamsdirectly in VisualAnalysis by defining slab properties along with the steel members.

Specification: You can choose between ASD and LRFD provisions.

See Steel Design (Section 5.4) other input design parameters.

Composite Beam Slab Parameters

Some of the following parameters have default values that you may define in preferences (Section 1.7) to speed upyour design work. These are 'per machine' default settings that only apply to new design groups you create.

Concrete

Shored: This option allows you to specify whether shored or unshored construction will be used. With unshored theconstruction load cases are enabled so that VisualAnalysis can correctly include the effect of construction loads on thebeam (see see construction load section above). With shored construction, no construction loads are necessary as themember is fully supported until it can act as a composite unit.

Strength f'c: Specify the concrete strength, f'c.

Thickness: Specify the slab thickness.

Weight: Choose the proper concrete weight to be used for the slab.

Beam Spacing: Enter the centerline to centerline distance between adjacent beams.

Is Spandrel: If yes, you are required to enter the overhang. Enter the distance from the centerline of the beam to theedge of the slab for the overhang distance.

Effective Width: The effective width of a slab is determined using the beam spacing, slab thickness, distance to aslab edge, and the span length. The effective width the design software calculated and used in the design checks islisted in the design report under "Slab and Deck Parameters".

Composite Beam Deck and Studs

Metal Deck

Deck Type: There are three choices for slab construction: no metal deck (solid slab), perpendicular metal deck andparallel metal deck. These are shown in the following sketches.



Rib Height/Rib Width: Deck dimensions for rib height and width must conform to the limits prescribed in AISC.These limits are automatically checked in the inspector. Refer to the diagram above when specifying the rib height andwidth.

The size and orientation of the deck will determine the effective thickness of the concrete slab, and may also reduce theeffectiveness of shear studs. AISC has placed certain restrictions on deck dimensions and the inspector will prevententry of numbers that are out of the allowable range.

Shear Studs

Stud Type: Shear studs may be headed studs or channels.

Stud Length: If you choose a headed stud, the length is interpreted as the height of the stud. For channel studs, thelength field is interpreted as the horizontal width. There is a minimum of 0.5" cover recommended. If you haveselected a metal deck, then the stud must also extend 1.5" above the deck.

Nr: The Nr parameter is only used for perpendicular metal decks and represents the number of studs per rib. Thenumber must be between one and three (more studs may be placed in the rib, but only three are allowed forcalculation purposes). Placing more studs in a rib may reduce the effective capacity of each stud. All of the appropriatestud capacity reductions are used to calculate the member strength.

Composite Beam Report

In the parameters section of the composite beam report there is more information included than simply what wasentered in the parameters dialog. Specifically there is a section about stud capacities and another with composite beamproperties. Both of these involve additional calculations using the parameters you defined. These sections contain moreinformation if the design group has a valid design shape.

In reporting shear stud requirements, the report contains minimum and maximum stud spacing requirements and thenumber of studs required between points of maximum and zero moment areas. VisualAnalysis does not produce adetailed stud arrangement schedule, but rather provides enough information for you to layout the studs.

If partial composite action is permitted, information will be shown regarding stud requirements for the minimum partial



composite action that provides the required moment capacity. VisualAnalysis does not perform calculations for any levelcomposite action between the full and minimum values reported.

Composite Beam Check Reports

The checks for composite beams are fewer than for general steel design. Axial forces, weak axis shearand bending, and weak axis deflection checks are not made. Forces, stresses, or deflections from these aresimply ignored in the software.

There are two types of strong bending checks performed for unshored construction: a Steel Flexure Check(Construction) and a Composite Flexure Check. The first is identical to the strong flexure check appearing in steelreports. The composite check uses a plastic distribution of composite forces. With shored construction only thecomposite check is performed and construction stresses are assumed negligible. The composite check unity value isequal to the moment demand divided by the fully composite moment capacity. Partial composite action is not reflectedin the unity check.

Composite deflections are approximated using the non-composite deflection reported from VisualAnalysis, and scalingthem based on the composite moment of inertia for the beam. The scaled deflections are then checked against yourspecified deflection limits. There is no provision in the software to specify a pre-camber or to ignore deflections fromcertain loads, other than how you choose your serviceability load cases.

5.9 Concrete DesignRequires: Design LevelDesigns are performed using the analysis results from VisualAnalysis and the parameters specified for each memberDesign Group or plate Design Mesh. American Concrete Institute strength design provisions (ACI 318-14) are checkedto determine whether the members or plates meets code requirements. In order to determine the controlling designloading, an iteration is performed for each element, at each location in that element where results exist and for eachstrength load case defined.

The process starts with a specification of member or plate configuration and minimum size parameters. The softwarewill search for acceptable preliminary designs, incrementing the size as required. Design selections are presented alongwith suggested reinforcement details that you can modify. A final check is then performed on your selection. Note,however, that the VisualAnalysis model will not be changed, as this would cause results to become invalid and thrownout. Instead, the Design Group holds the results until the model is synchronized. Once the design changes aresynchronized, the model must be re-analyzed in order to get final unity checks.

You may use either metric or USA rebar types in the design of concrete. There is a preference setting for all futureprojects and there is a project setting (Section 2.2) in the Project Settings to direct VisualAnalysis to select rebarfrom the appropriate category for you during the design process.

Concrete Design Types

Concrete Beam Design (Section 5.10)Concrete Column Design (Section 5.11)Concrete Slab Design (Section 5.12)

Concrete References

1. American Concrete Institute, ACI 318-14, Building Code Requirements for Reinforced Concrete.

2. Wang & Salmon, Reinforced Concrete Design, 5th Edition, HarperCollins Publishers, Inc, 1992.

3. American Concrete Institute, Design Handbook, Volume 2 Columns (SP-16A), ACI, 1985.

5.10 Concrete Beam Design




Concrete Beam Capabilities

The concrete beam module allows VisualAnalysis to design and check concrete beams based on the ACI 318-14 CodeProvisions. The beam may have one of three shapes:

1. Rectangular (isolated beam)2. Spandrel Beam (slab extension one side only)3. Tee (slab extension both sides)

When modeling Tee and Spandrel shapes the slab thickness is defined in the modeled shape and is not changed bythe design software. A design search for a shape that work will modify only the stem thickness and the overall depth.For Tees, the slab width for the modeled shape is not used during the checks, but the effective width calculatedaccording to ACI and your input value for beam spacing is used. For Spandrels, the slab width (overhang) is assumed tobe fixed and is used along with beam spacing in determining the effective width.

Bending behavior is assumed to be uniaxial only. (For biaxial checks or significant axial forces, use the column module.)The design module may be used to take into account the effect of torsion in addition to bending and shear. The modulealso suggests a reinforcing pattern and stirrup spacing. A standard beam detail, as shown below, with three sets of topbars and two sets of bottom bars is assumed. Once a reinforcing system is chosen, the module checks the designdetails for strength and spacing criteria.

Results tabulated include strength provided and strength required (both flexure and shear) as well as reinforcementspacing information. The design and subsequent checks are determined for those load cases that have been createdwith the strength Design Category (Loading | Load Case Manager). You should only select load cases that haveappropriate ACI load factors defined to use with the ACI Beam Design Module. The unity check values for flexure andshear for the worst load case are shown graphically in Design Windows.

Rebar Key

TL Bars: Main reinforcing steel for the top left (node 1 end) third of the beam.

TC Bars: Main reinforcing steel for the top of the beam, and continuous across the supports..

TR Bars: Main reinforcing steel for the top right (node 2 end) third of the beam.

B Bars: Main reinforcing steel for the bottom center third of the beam.

BC Bars: Main reinforcing steel for the bottom of the beam, and continuous across the supports.

S Bars: Reinforcing steel for the sides of the beam for deep beams or torsional strength. The number of bars shownmust be provided on EACH side of the beam.

Concrete Beam Assumptions and Limitations

This section summarizes the assumptions made in the concrete beam design module. It also includes severaldiscussions that are very critical to the proper use of the design module. You are encouraged to read the attachedsections before using the software.



Beams are assumed to be modeled from column-to-column. You should not split your beam into multiplemember elements. A beam spanning supports may cause inaccurate results.Left/Right sides of beam correspond to the member local axes (Section 2.4), so the 'start node' is on theleft and the 'end node' is on the right.Rebar is calculated for each 1/3 span. Rebar is assumed to be terminated at the 1/3rd points of the beam.Development length issues are not considered in the software.Normal weight concrete is assumed.No axial forces or biaxial bending is considered. Use the column design module if these forces are present.When a member is subjected to high torsion, you will be prompted to provide information regarding whetheror not this member is part of an indeterminate torsional system. The ACI code allows higher strengthprovisions for indeterminate torsion. See ACI section 11.6.2.2 for more information.Special moment resisting frame is not used for seismic. This module assumes that the conditions of ACI 9.3.4do not apply. In other words, the member is not part of a structure that relies on special moment resistingframes or special reinforced concrete structure to resist earthquake effects. Only the shear f (phi) factormodifications of ACI 9.3.4 will be used if you so indicate in the Beam Parameters area of the inspector.The Design shear demand is calculated at distance d from the face of the support column, where 'd' is thedepth of the reinforcement steel measured from the compressive face to the steel centroid. This is consistentwith ACI 11.1.3 assuming the conditions specified in that section are met. It is left to the user to ensure therequirements of 11.1.3 are satisfied. If they are not satisfied, it is left to the user to perform the designoutside of the software.Shear steel (stirrups) are assumed to begin at 3" from the face of the support, as shown in the standardbeam detail.Top flexure steel checked at the support. For flexural calculations, the critical section for top steel is taken atthe face of the support since the member has nearly an infinite depth once it reaches the support.Splitting members is not recommended. You should be careful about trying to design members that havebeen split into multiple member elements. The reinforcement details assume that the endpoints of themembers are at supports. For the best design results, you should use the Structure | Combine Membersfeature to combine elements into a single member.Cutoff lengths and locations are not determined by the softwareNo "diagram" is produced to graphically display the bar locations or stirrup arrangements. There is a'schedule' in the report with a list of bar requirements.Bracing is not a parameter for concrete design. All beams are assumed to have adequate lateral support toprevent rotation.Deep beams, as defined in ACI 11.7.1, cannot be designed in VisualAnalysis. VisualAnalysis will warn you if abeam has a clear-span length less than 4h. However, if you use a combined member to span across multiplesupports the program's check will not be accurate. VisualAnalysis does not check for concentrated loadswithin 2h of the support face. It is left to the user to detect this situation and perform an appropriate designoutside of the software.

Concrete Beam Parameters Overview

In selecting member sizes, reinforcing details, and subsequently checking a concrete beam, several parameters must bedefined. The design parameters are controlled completely through the Modify tab of the Project Manager in the DesignView. Prior to executing design checks, you should select one of the members that belongs to the design group in theDesign View and go to the Modify Tab of the Project Manager and set up the design parameters.

Keep in mind that the parameter information you enter applies to all members of the design group, so it may be wise tochoose the most conservative condition that applies to any member in the group.

Concrete Beam Parameters

Member Type: Indicates the design shape (Beam or Column).



Overstrength?: Causes the member to be designed for overstrength forces per ASCE 7 and ACI 318

Disable Checks?: Causes selected design group to be omitted from design checks.

High Seismic Risk - (Use Reduced Phi Factors for Members Resisting Earthquake Effects) This tells thedesign module to apply the lower PHI factors as indicated by ACI Code section 9.3.4 for members which are designedto resist earthquake effects and are part of a structure that relies on special moment resisting frames or specialreinforced concrete structural walls to resist earthquake effects. Note that the program relies solely on this parameter indetermining whether or not to use the reduced f (phi) it does not attempt to calculate whether the shear capacity isgreater than the shear corresponding to the development of the nominal flexural strength of the member. Only the Phifactor for the shear is affected by this entry.

Design Parameters

Slab Thickness: (Not shown) For Tee or Spandrels, the slab thickness is defined by the modeled shape, and is notentered directly in the design parameters.

Minimum Depth: The first value for depth that the program tries as it iterates over sizes in search of a satisfactorysection. It will start from this size and go up. If the width needs to be fixed at a certain size, that size should bespecified as the Minimum and Maximum Depth and the Increment Depth parameter should be set to zero.

Maximum Depth: The maximum value for depth that the program tries as it iterates over sizes in search of asatisfactory section.

Increment Depth: The amount by which the program increases its "trial" depth as it iterates over sizes in search of asatisfactory section. If the depth needs to be a specified value, enter zero for this increment (the depth value will bethat specified by the Starting Depth parameter).

Minimum Width: The first value for width that the program tries as it iterates over sizes in search of a satisfactorysection. It will start from this size and go up. If the width needs to be fixed at a certain size, that size should bespecified for Minimum and Maximum Width and the Width Increment parameter should be set to zero. For Tees andSpandrels, this is the Stem Width.

Maximum Width: The maximum value for width that the program tries as it iterates over sizes in search of asatisfactory section.

Increment Width: The amount by which the program increases its "trial" width as it iterates over sizes in search of asatisfactory section. If the width needs to be a specified value, enter zero for this increment (the width value will bethat specified by the Starting Width parameter).

Beam Options Parameters

Main Fy:: Specified yield strength of the longitudinal (flexural) reinforcement in the beam.

F'c: The specified compressive strength of the concrete.

Beam Spacing: The perpendicular spacing between beams (centerline to centerline). This is used for Spandrel andTees to determine the effective flange width. This parameter is not necessary for beams with rectangular cross sectionsand will not be available.

Top Cover: Concrete clear cover at the top of the section. Calculated as the distance from the top of the stirrup to thetop of the section.

Bottom Cover: Concrete clear cover at the bottom of the section. Calculated as the distance from the bottom of thestirrup to the bottom of the section.

Start/End Column Widths: Widths of supporting columns at start and end of beam. These widths are used fordetermining where critical shear and moment sections are at the ends of the beam. The critical moment is located atthe face of the column and the critical shear is located at "d" from the face of the column. These ends correspond tothe member's local axes (Section 2.4), where local x goes from the start-node to the end-node.

Concrete Beam Stirrups Parameters



Stirrup Fy: Specified yield strength of the stirrups in the beam.

Size: Size of the stirrup bars.

Number of Legs: Number of vertical legs per stirrup. A value of 2 indicates normal U-shaped stirrups.

Symmetric? Option specifying that the beam stirrups are to be laid out symmetrically about the beam centerline.

Concrete Beam Design Process

1. Specify preliminary member size and Material (Model View) , and Design Parameters (DesignView)

Concrete members are created using Standard Parametric cross sections. You will also need to apply loads and set upstrength design load combinations. For more details on these 'basic' steps, please see: The Design Process)

2. Analyze your model, and select the Design View Tab to check the Unity Ratio.

If the cross section created in the Model View meets strength requirements, reinforcement will be sized to meetdemands.

3. Manually adjust reinforcement (optional)

The sized longitudinal reinforcement and stirrup spacing can then be adjusted to your preference while in the DesignView (Modify Tab, Details Heading, Adjust Rebar [...] button). Unity checks will then be updated in the Design View.

You can iterate steps 1-3 to obtain a final design, or you can use the Design feature in VisualAnalysis for optimizingdesign by continuing with the following steps:

4. Design The Group

Select a group from the Design View window. Then use the menu item Design | Design Members… .

5. Select a Beam Size

From the dialog you a may select an appropriate beam size. Unity Ratios are shown in the table to indicate just howclose you are to code allowed maximums. Once you chose a size, a suggested set of reinforcement will be shown ifpossible. The ~ symbol indicates unity ratios must be validated with another analysis (because member stiffness mayhave changed).

6. Adjust Suggested Reinforcing Details

Initially the suggested reinforcing patterns that should meet code requirements are presented. If you are not satisfiedwith the suggestions, change the values as you see fit (Similar to step 3).

7. Synchronize Design Changes

Analysis results exist for the modeled shape, and are affected by member stiffness. In order to provide final verificationof designed shapes, the menu item Design | Synchronize Design Changes must be selected. This will update themodeled shape to that selected in the design process.

8. Verify Unity Ratios in the Design View

The final step in the design process is to verify that Unity Ratios (Design View) are less than unity. If member sizeswere drastically changed during the design process, final unity ratios can differ from predicted unity ratios because theanalysis results may vary significantly.

Concrete Beam Reports



The design reports produced by the design module are available by simply double clicking on the member while in theDesign View. This will report section material, reinforcement and code checks. The right click context menu alsoallows quick generation of design reports.

5.11 Concrete Column DesignRequires: Design Level

Concrete Column Capabilities

The concrete column module allows VisualAnalysis to design and check concrete columns based on the ACI 318-14Code Provisions. The column may have one of four configurations:

Rectangular with bars on 2 opposite facesRectangular with bars on all four faces (evenly distributed)Square with a circular bar patternCircular with a circular bar pattern

The design module takes into account the effects of slenderness by using the ACI moment magnifier method. Themoment magnifier for member strong and weak axes default to 1.0. For columns in frames that may have sidesway,you must enter a cumulative moment magnifier directly, or you may use P-Delta analysis results per ACI 10.13.4.1. Checks are performed if slenderness needs to be considered.

The design module also calculates effective length factors (k factors) automatically. The calculations are based onsection 10.12.3 of ACI 318.

Regular ties may be used for all columns and spirals may be chosen for the circular bar patterns. The module alsosuggests a reinforcing pattern and tie/spiral spacing.

Results tabulated include interaction equation results as well as a plot of the interaction diagram for the column. In thecase of biaxial bending, the Parme interaction equation is used for checking adequacy.

The design checks are determined for those load cases that have been created with the strength check box checked.You should only select load cases that have appropriate ACI load factors defined to use with the ACI Column DesignModule. The interaction equation value for the worst load case is shown in the Design View. A graphic interactiondiagram is displayed in a report, showing the interaction point for each of the strength load cases.

Concrete Column Limitations

Column Forces

The columns are designed for compressive axial force plus either uniaxial or biaxial bending. Tension in columns isnot designed or checked, some is allowed if determined to be negligible. Furthermore, the effects of shear andtorsion are neglected in the column checks.

Reinforcement Distribution

All column capacity calculations are based on the assumed location of the reinforcement. Four face patterns areassumed to have an equal number of bars on each face, and are spaced evenly along each face. Interaction diagramsare created based on the selected details and the associated steel locations. Points on the interaction diagrams arecalculated by varying the neutral axis depth and solving for the axial and flexural capacities. Phi factors are applied tothe capacities based on the extreme tensile strain in the reinforcement. If the centroid of a reinforcing bar is locatedwithin the concrete compression block, the stress in the bar is reduced by the magnitude of the concrete compressionblock.

Reinforcement Distribution and Member Local Axes



Bars specified as distributed to 2-faces are located on the +y and -y faces (local member axes) ofthe column. This corresponds to conventional strong bending (bending about the z-z axes. Thepicture on the right illustrates a typical distribution. The beta angle will rotate the local axes,which will also rotate the orientation of the faces on which the rebar lies. Note that a parametricrectangle can be defined as 12"wide x 24"high, or 24"wide x 12"high. It is critical to pay attentionto local axes direction when specifying reinforcement on two faces. Turning on the PictureView filter and the Member Local Axes filter will help you orient the parametric shape with thelocation of the reinforcement. Creating a couple of simple test cases and reviewing the UnityRatios for a given loading can also help determine what reinforcement distribution exists.

Moment Magnifiers

When a member is allowed to have sidesway and is found to be slender, the design module requires you to enter themoment magnifier. Otherwise, the module determines the moment magnifier for you. When calculating the magnifier incases where sidesway is prohibited, the larger of the EI values from ACI equations 10-11 and 10-12 is used.

Parme Equation

In the case of biaxial bending for rectangular and square sections, an interaction equation is used to determine theadequacy. The equation used by this module is the Parme equation.

See "Reinforced Concrete Design", by Wang and Salmon for more information. The Parme equation has the followingform:(Muy/Moy) exp + (Muz/Moz) exp < 1.0where:Muy = Factored moment about section y axis.Moy = Factored moment capacity (uniaxial) about section y axis.Muz = Factored moment about section z axisMoz = Factored moment capacity (uniaxial) about section z axisexp = Exponent = -0.30103/log10(beta)beta = Parme equation "Beta" (0.5 < beta < 1.0)

Column Design Length

The column design length is assumed to be the clear spacing between beams at each end. Note that any internalmember forces beyond the column design length are ignored.

Member Section Axes

The column cross section is oriented relative to the lcoal y and z-axes. All concrete design checks are in terms of thesection axes (only different for spandrels).

Concrete Column Parameters Overview

In selecting member sizes, reinforcing details and subsequently checking a concrete beam, several parameters must bedefined. The design parameters are controlled completely through the Modify Tab of the Project Manager in thedesign view. After creating a design group, you should select one of the members that belongs to the design group inthe Design View and go to the Modify Tab of the Project Manager and set up the design parameters.

Keep in mind that the parameter information you enter applies to all members of the group, so it may be wise tochoose the most conservative condition that applies to any member in the group.

Concrete Parameters

Member Type: Indicates the design shape (Beam or Column).

Overstrength?: Causes the member to be designed for overstrength forces per ASCE 7 and ACI 318



Disable Checks?: Causes selected design group to be omitted from design checks.

High Seismic Risk - (Use Reduced Phi Factors for Members Resisting Earthquake Effects) This tells thedesign module to apply the lower Phii factors as indicated by ACI Code section 9.3.4 for members which are designedto resist earthquake effects and are part of a structure that relies on special moment resisting frames or specialreinforced concrete structural walls to resist earthquake effects. Note that the program relies solely on this parameter indetermining whether or not to use the reduced f (phi) it does not attempt to calculate whether the shear capacity isgreater than the shear corresponding to the development of the nominal flexural strength of the member. Only the Phifactor for the shear is affected by this entry.

Design Parameters

Minimum Depth: The first value for depth that the program tries as it iterates over sizes in search of a satisfactorysection. It will start from this size and go up. If the width needs to be fixed at a certain size, that size should bespecified as the Minimum and Maximum Depth and the Increment Depth parameter should be set to zero.

Maximum Depth: The maximum value for depth that the program tries as it iterates over sizes in search of asatisfactory section.

Increment Depth: The amount by which the program increases its "trial" depth as it iterates over sizes in search of asatisfactory section. If the depth needs to be a specified value, enter zero for this increment (the depth value will bethat specified by the Starting Depth parameter).

Minimum Width: The first value for width that the program tries as it iterates over sizes in search of a satisfactorysection. It will start from this size and go up. If the width needs to be fixed at a certain size, that size should bespecified for Minimum and Maximum Width and the Width Increment parameter should be set to zero. For Tees andSpandrels, this is the Stem Width.

Maximum Width: The maximum value for width that the program tries as it iterates over sizes in search of asatisfactory section.

Increment Width: The amount by which the program increases its "trial" width as it iterates over sizes in search of asatisfactory section. If the width needs to be a specified value, enter zero for this increment (the width value will bethat specified by the Starting Width parameter).

Rebar Pattern: Specifies if bars are to lie on 2-faces or 4-faces (Rectangular and Square sections) , Round Spiral(Square sections),and Round Spiral or Tied (Circular sections)

Main Steel Fy: Specified yield strength of the main longitudinal steel in the column.

F'c: The specified compressive strength of the concrete.

Cover: Clear cover between outer concrete surface and outer surface of ties or spiral.

Confinement Parameters

Tie Steel Fy: Specified yield strength of the ties or spiral.

Tie Steel Size: Size of reinforcing steel to use for ties and spirals.

Columns Parameters

Parme Equation Beta: The beta coefficient to be used when evaluating the Parme interaction equation for combinedcompression and biaxial bending. This value must be between 0.5 and 1.0.

Allow Moment Magnification: Option allowing slender columns to be designed per the limit of ACI equation 10-7. Ifyou choose to not consider moment magnification, column sizes will be chosen so that the slenderness does not exceedthe limit of ACI equation 10-7 or section 10.13.2.

My/Mz Magnifier: The combined delta-ns and delta-s moment magnifier. Used only when sidesway is allowed (forbraced frames, ACI equations 10-8 through 10-12 are used).

See common Design Parameters (Section 5.1.2) for a description of other settings.



Concrete Column Design Process

1. Specify preliminary member size and Material (Model View) , and Design Parameters (DesignView)

Concrete members are created using Standard Parametric cross sections. You will also need to apply loads and set upstrength design load combinations. For more details on these 'basic' steps, please see: The Design Process)

2. Analyze your model, and select the Design View Tab to check the Unity Ratio.

If the cross section created in the Model View meets strength requirements, reinforcement will be sized to meetdemands.

3. Manually adjust reinforcement (optional)

The sized longitudinal reinforcement and tie spacing can then be adjusted to your preference while in the Design View(Modify Tab, Details Heading, Adjust Rebar [...] button). Unity checks will then be updated in the Design View.

You can iterate steps 1-3 to obtain a final design, or you can use the Design feature in VisualAnalysis for optimizingdesign by continuing with the following steps:

4. Design The Group

Select a group from the Design View window. Then use the menu item Design | Design Members… .

5. Select a Column Size

From the dialog you a may select an appropriate column size. Unity Ratios are shown in the table to indicate just howclose you are to code allowed maximums. Once you chose a size, a suggested set of reinforcement will be shown ifpossible. The ~ symbol indicates unity ratios must be validated with another analysis (because member stiffness mayhave changed).

6. Adjust Suggested Reinforcing Details

Initially the suggested reinforcing patterns that should meet code requirements are presented. If you are not satisfiedwith the suggestions, change the values as you see fit (Similar to step 3).

7. Synchronize Design Changes

Analysis results exist for the modeled shape, and are affected by member stiffness. In order to provide final verificationof designed shapes, the menu item Design | Synchronize Design Changes must be selected. This will update themodeled shape to that selected in the design process.

8. Verify Unity Ratios in the Design View

The final step in the design process is to verify that Unity Ratios (Design View) are less than unity. If member sizeswere drastically changed during the design process, final unity ratios can differ from predicted unity ratios because theanalysis results may vary significantly.

Concrete Column Reports (Interaction Diagrams)

The design reports produced by the design module are available by simply double clicking on the member while in theDesign View. The right click context menu also allows quick generation of design reports.

This will report section material, reinforcement and code checks, as well as an interaction diagram. The interactiondiagram is generated with reports and plots factored axial load vs. factored moment. Each strength load case resultappears as a point on the diagram and the values plotted. The "Key" to these data points is in the Load Cases table,



which numbers each load case and load combination. A .01 notation indicates the 1st set of results (e.g. linear) a .02indicates P-Delta results. If a point falls within the diagram, it satisfies strength criteria.

5.12 Concrete Wall/Slab DesignRequires: Design LevelVisualAnalysis allows you to check flat reinforced concrete slabs (or walls in pure bending). There are no capabilitiesfor shear walls and the software does not check footings or foundations (no punching shear checks).

Capabilities

The Slab design uses 3-4 node plate/shell finite elements. These elements are grouped together in logical groups calleda Design Mesh. A typical rectangular tank for example with open top might have five such meshes, one for each walland one for the base slab. The Slab design is also compatible with auto-meshed areas. A Design Mesh may consist ofa single auto-meshed area. Manual plates and auto-meshed areas are not allowed to be grouped together in the sameDesign Mesh. Design meshes are created automatically if the Project Settings "auto-group" option is enabled. You mayalso manually construct design meshes for manual plate meshes.

Concrete Slab Checks

The Wall/Slab module will design wall and slab-type structures based on ACI 318 concrete code strength provisions.Strength checks made include shear and flexure.

Local Coordinate System

The Wall/Slab module attaches a local coordinate system to all panels designed. An individual slab has associated withit a local-x direction and local-y direction for rebar orientation, and a top and bottom face (used to reference thedifferent mats of reinforcement). The local coordinate system has x and y in the plane of the mesh, with the +z formednormal to the plane according to the right-hand-rule. You can display the local x-y directions in the Design Viewwindow.

For design meshes associated with a meshed Area object, the local coordinate system will line up with the "SpanDirection" specified for the area. For a mesh of manually created plate elements, the local-x and local-y directions areset by the software based on the local x-axis of the "first" plate in the mesh, which you have no control over, so it isuseful to align ALL your plate elements the same way.

Steel Reinforcement

The slab, wall, or panel as it is referred to here will consist of a single region for rebar layout. If you need more regionsthan this, you will need to manually create your mesh in different groups for design. Rebar is oriented with the localcoordinate system for the Design Mesh. Rebar is specified as a bar size and spacing for each bar layer in each direction.The software simply checks the rebar layout and details that you specify, the "default" or starting rebar configuration isjust the smallest bar at some fairly large spacing.

When two layers of steel are needed, four bar groups exist in the region:

1. top layer local-x bars2. top layer local-y bars3. bottom layer local-x bars4. bottom layer local-y bars.

When a single (centered in thickness) layer of steel is used, only two bar groups exist in each detail region; local-y andlocal-x bars. The local x-bars are assumed to be the top layer.

Limitations

This section summarizes the assumptions made in the concrete wall/slab design software module. It also includes



several discussions that are very critical to the proper use of the design module. You are encouraged to read theattached sections before using the software.

Flat Slabs Only

There are no provisions for waffle slabs, ribbed slabs, or column capitals. Only flat walls or slabs are checked.

No In-Plane Forces

We check pure-bending only. No shear wall or bearing wall design. The Wall/Slab module does not look at in-planeforces in a slab. If walls have axial loads these are not considered in the design. Shear walls are not supported by thismodule. The software will check for 'significant' in-plane forces and report the problem with a warning.

Critical Section for Moment and Shear

The Wall/Slab module does not consider critical section for edge moment at the face of the support or shear at 'd' froma support point. The software currently does not try to detect or allow you to specify specific support locations.

Mesh Shape and Orientation

The Wall/Slab module has been written to design arbitrarily shaped mesh of connected elements, which all must lie inthe same plane. Curved walls (even when approximated with flat plates), such as circular tank walls, cannot bedesigned.

Shear Strength

This program does not consider shear steel; therefore, all shear strength is attributable to the concrete shear strength.Normal weight concrete is assumed. The software does not consider punching shear near columns in the mesh.

Parameters

The following parameters are used to control the unity checks made for the wall/slab design mesh:

Wall/Slab Name: A name for you to use

Specification: ACI version

High Seismic: ACI seismic provisions are used.

ACI Wall Minimum: Minimum wall steel is checked. (ACI14.3)

Concrete f'c: Set by plate or area in the Model

Details Thickness: thickness of wall or slab to check, if you changethis you can 'synchronize' to update the model, which willcause analysis results to be thrown out.

Bar details: Rebar you specify for checks.

Reinforcement Steel Fy: Yield stress for rebar

Bar Layers: Two or one-center layer

Outside Layer: Specify either x- or y-direction bars

Top/Bottom Cover: Clear distance to outer bars from face.

There is no way to control the wall-width settings; we now "smartly" check shear (at the centroid of elements not atthe perimeter nodes.) This allows for arbitrary geometry slabs, prior versions of VA were only accurate for rectangular-



shaped slabs.

If you wish to, you could manually remove plate elements around the "perimeter" of mesh from the design-checks toprevent any local/artificial shear-spikes from interfering with good checks. This way the system is less of a "black box"and you can take-charge as necessary. To do this you would:

1. Turn off the "Auto-Group" feature in Project Settings2. Turn off the "Toggle Groups" feature in the Filter tab for the Design View3. Select some of the "perimeter" plates in a mesh and remove them from the design group.

The information in the parameters is accessible to you through the Modify tab in Project Manager. The parameterinformation you enter applies to the entire design mesh. You may select multiple design meshes and edit many of theparameters at one time. After making a change all of the unity checks will be recalculated unless there are no analysisresults, or you have "Suppressed Unity Checks" [Advanced level only].

The "Design Group" feature that was available in VA 8.0 and prior is now gone because it is was longer necessaryafter the simplifications in VA 9.0, see below for details...

Design "Procedure"

The "Design" of your slab consists of two things: the Slab Thickness that you set in the design view and the RebarLayout you choose. When the checks pass you have a successful design! The only thing that "synchronizes" back tothe model is the slab thickness, so if you change that you must synchronize the change and re-analyze to get updatedforces/stresses in the slab.

Reports

To understand the unity-check values displayed in the Design View, you can double-click on a Design Mesh in theDesign View to generate a report. The report includes (optionally) the input parameters, the design details (rebar) andthe code checks performed showing demand, capacity, intermediate values and unity check results. A code orspecification reference is provided for each check. If there are errors or warnings this information will appear near thetop of the report.



6 Report

6.1 ReportsDocumenting your work clearly, concisely and in an organized fashion is crucial to the success of any structural project.Structural analysis and design is often 50% bookkeeping, and understanding the reporting features in VisualAnalysiscan help transform your business. When we discuss reporting we are generally referring to information that you willprint, whether that information is text-based or graphical. Whatever you see graphically in VisualAnalysis can beprinted, either directly (File | Print) or through a Copy and Paste command into a text report or another Windowsapplication.

Tables (Section 6.2): Descriptions of the items you may include in a report.Working in the Report View (Section 9.7)Managing Report Styles (Section 6.3): re-usable reports, stored per-machineReport Notation (Section 6.4): column headings are short, here is a key to our notation.

Managing Reports

See Working in Report View (Section 9.7)

Controlling Verbosity

Reports may be filtered based on selected, named, or all model objects. These filters only appear when you includetables that hold that type of object. You can also filter reports for load cases (load tables) or result cases, using all orselected cases.

Included Tables

You may include one or more tables (Section 6.2) in your report by dragging them from the Add Tables tab ofProject Manager. You can rearrange them by dragging them in the Modify tab of Project Manager. To select a table(for editing) you can click within the table in the Report View.

Modeling for Reports

Using good names for members, plates, nodes, etc. can improve your reporting abilities. VisualAnalysis provides somesmart-naming, but by renaming groups of items you can make it easier to sort, find and filter your model bothgraphically and in reports. Use the Structure | Rename feature to group similar items by name, then use objectName Filters in reports to shrink them down to only relevant items.

Custom Report Logo

The report may be customized to include your own (company) logo in the header. All you need to do is create a logoimage: ReportLogo.png or ReportLogo.jpg, and place it in the IES\Customer folder, which you can access via the Tools| Custom Data toolbar command. The image should be kept to less than 5 times wider than it is tall. It will be scaledto fit in the header area, but wide images may cause other text to start wrapping or get truncated. If the image worksyou'll see it in the report/preview immediately after restarting VisualAnalysis. (This logo works for ShapeBuilder andVisualFoundation as well.)

6.2 TablesReport tables show a grid of data that might need to be sorted or filtered. Tables often have optional column optionsfor data that is not displayed by default. You may include multiple tables of the same type but display different columnsin each and use different filter settings to achieve dramatically different reports.



Not every table type is useful to every IES customer or in every project. Some tables work best for a few selectedobjects and will grow gigantic in a larger project. Other tables are great at condensing large amounts of data into aconcise summary.

Table Options

Click the mouse within a table to access the table's properties in the Project Manager. Click a column header to sort.Drag a column header to rearrange the columns. You can add or remove columns from the table.

Types of Tables

Tables are available in the Add Tables tab of Project Manager when you are in the Report View. Tables willautomatically appear and disappear as you add or remove elements, loads, cases, and also when VisualAnalysiscalculates results or design checks. Only tables that make sense for your project and license level will be visible.

Model Input

Tables exist to display your input data for all kinds of model objects including Nodes, Member Elements, Plate Elements,Cables, Spring Supports, and Areas. There are tables for special types of members like Tapered Members, OffsetMembers, One-Way Members, etc. You may report Material Properties and Section Properties for all the elements usedin your project.

Model and Project Information

There are tables to help you better understand your model and project, including a Model Summary, a Bill of Materials,a Model Check, and Project Settings.

Loading Input

There are tables to display each and every load applied to the model objects listed above, for each of the service loadcases defined. These include Nodal Loads, Member Point Loads, Member Uniform Loads, Plate Pressure Loads, etc.Area loads may be reported as well as the "Generated Loads" (that are applied through areas to member elements). Allof the various load cases have tables too: Service Load Cases, Factored Combinations, Equation Load Combinations,Dynamic Response Cases, and more.

Analysis Results

All of the "typical" result tables for simple results on every type of model object are available for displacements, forcesor moments, and stresses as applicable. These include Nodal Displacements and Reactions, Member Internal Forces,Spring Results, etc. Results may be available in both 'local' and 'global' directions or in a variety of extreme or min/maxconfigurations. Each table meets someone's particular need depending on whether you are reporting 1000 members, ora single member, for example.

There are numerous ways to report member results so you should experiment with the various types of tables to selectthe one that is appropriate for your situation(s). Member elements have different types of displacement (or deflection,or drift) reports to satisfy various needs

Design Aides

Some helpful tables report analysis results, but configured or processed from raw analysis to be used in design checks.Things like the Member Relative Deflections, Column Lateral Drift, Lateral Stability Index Results, Member K Factors,Design Connection Forces, Member Moment Magnification, or Self Weight & Center of Mass tables are not design-checks, per say, but will help you with your various design tasks.

Design Reports

Requires: Design LevelYou can report input data for your design groups along with unity checks (by check type), and design details (like rebarselections for concrete) by including "Design Group Results" item. The unity checks will show demand, capacity, someintermediate calculation results (like Cb or Lu) values, and the controlling code reference. A Member Unity Checks tableis a very concise design-status for all the members in your project.



6.3 Saved StylesSetting up a custom report can take some time and energy. Report styles let you preserve that effort.

Create a Style Report

Any time you like you can re-create a saved report by selecting it in the Reports tab and clicking the Create button.

Save a Project Report

Using the Reports tab in Project Manager you can name your report to save it in your project file, for easy accesslater.

Save a Report Style

The Reports tab also lets you save a report as a template for future projects. These reports are saved in your IESData folder (Section 1.9) in an XML file (text file) that can be copied to other machines. If you are brave you canedit the file in Notepad or merge styles from other people. Be sure to make a back up copy before doing anycustomization manually. If the file gets corrupted you can delete it to get a default (empty) file, or restore your backup.

Edit a Report Style

Report styles may be replaced but not edited directly. Create a report based on a style, change the report settings andthen save it as a new style.

Delete a Report Style

To delete a style, select it using Reports tab in Project Manager and choose Delete Style. No warning is presented,but if you decide you really do not want to delete the style, just hit Cancel in the dialog box. All changes you havemade to styles will be lost. Once a style is deleted, there is no way to restore it, except to recreate it from scratch or toimport it from a backup copy of the style file. See the chapter on Customizing for more information about style files.

Share Report Styles

You may share your report styles with another VisualAnalysis user by copying the style file. This file is found throughTools | Custom Data. See Data Files (Section 1.9) for more details. The file is in .XML (text) format, and you canedit it in any text editor to make minor changes, merge style files, or remove individual styles. Be sure to make abackup in case the file gets corrupted. If you invest a lot of work in to customized reports, you might want to save abackup copy of your style file in a safe place.

6.4 Report NotationThe following table describes IES notation used in reports. This notation is also used in input panels (Modify tab) theFind Tool, and in graphics.

Quick Tips:

Lower-case x, y, z represent local or section coordinate directions.Upper-case X, Y, and Z represent global coordinate directions.For members, x is the axial direction!Sign convention for members and spring supports, axial forces: + = tension, - = compression

ColumnHeading

Description

% Damping Damping factor used in modal superposition



%Iy, %Iz,%J

Percent of stiffness to use during analysis of cracked materials

Action Member behavior: normal (two-way), tension-only, or compression-only

Alpha Thermal coefficient of expansion, for a material.

Area Area of plate

Auto Mesh Signifies whether an area is meshed with plates

Ax Cross sectional area

Beta Beta Angle - rotates the member local coordinates, also an input parameter for time history analysis,or Parme Beta in concrete design

Cases Number of load cases included in the combination

Category Type of shape within a database

Cluster Factor Cluster factor used in modal superposition

CombinationMethod

Response case modal combination method

ConnectCrossings?

When mapped to the FEA model, should the member be split and connected to members crossing it.

D. Mass Lumped translational mass

Delta Input parameter for time-history analysis.

Delta t Time step interval for time history analysis.

Density Weight density of a material (also Gamma)

DesignSpectrum

Name of design spectrum

Dim. 1 - Dim.6

Cross section dimensions, meaning depends on type of shape

Direction Global direction of a nodal load or member load. Direction of spring support. Also direction of a Semi-Rigid connection (advanced only)

Displacement Displacement result in spring

DX, DY, DZ Displacement in the global X, Y, or Z direction

Dx, Dy, Dz Local member displacements in the x, y, or z direction

Dx1, Dy1,Dz1,Dx2, Dy2,Dz2

Displacement release in the local x, y, or z direction at the starting(1) or ending(2) node

Elasticity, orE

Modulus of elasticity or Young's Modulus, E

Elements Number of members or elements in the group or mesh

End Offset Distance from the starting end of the member

End zone 1,End zone 2

Type of end zone (normal, panel, or rigid) at the start(1) or end(2) of a member.

ColumnHeading

Description



EZ Width. 1,EZ Width. 2

Width of the end zone at the start(1) or end(2) of a member

EZ Stiffness 1EZ Stiffness 2

Percent of the member stiffness to use in the end zone region at the start(1) or end(2) of a member

Equation Equation name or description

Exclusive True or false, indicates whether the load case requires unique building code combinations, as fordirectional wind or seismic load sources.

Extreme Item Type of results

f(Hz) Frequency of vibration in cycles per second

fa Axial stress in a member (tension is positive, compression is negative).

fby(+z), fby(-z)

Bending stress in a member bending about the section y-axis, at the extreme z fiber

fbz(+y), fbz(-y)

Bending stress in a member bending about the section z-axis, at the extreme y fiber

fc max, fcmin

Extreme value of combined bending and axial stress at the section "corners", may be incorrect fornon-rectangular shapes!

fc(+z+y),fc(+z-y), fc(-z+y), fc(-z-y)

Superimposed bending and axial stresses at section "corners", may be incorrect for round, tee, L,and other shapes without corners at a 'bounding rectangle' drawn around the shape. See MemberResults (Section 2.4)

fvy, fvz Average shear stress on a member: Vy/A and Vz/A, respectively. These are not the "extreme" shearforces on the cross section as VisualAnalysis cannot calculate that information.

Final Shape Designed member size or section name

Fix DX, FixDY,Fix DZ

Supported against translation in X, Y, or Z

Fix RX, RY,RZ

Supported against rotation about X, Y or Z

Force Reaction force in spring supports.

Framing Member 'category' (beam, column, or brace) used to exclude braces from area loads

Fx Axial force in a member (tension is positive, compression is negative).

FX, FY, FZ Reaction force in the global X, Y, or Z direction

Gamma Density of a material (g)

Iy, Iz Moment of inertia about the local axis

J Torsion constant

L.FX, L.FY,L.FZ

Sum of applied loads in the global X, Y, or Z direction

L.MX, L.MY,L.MZ

Total moment about X, Y, or Z of applied loads, taken about the global origin

Length Length of member

ColumnHeading

Description



Load Case Name of a load case

Load Source Type of loads in this load case

Loads Number of loads in the service load case

Location Node name or plate centroid where plate results are located

Magnitude Force, moment, displacement or rotation of a nodal load. Value of member load.

Magnitude1,2

Starting or ending distributed member load

Mass Case Static load case included in a response analysis

Mass Dir. Direction of gravity for loads in response analysis

Material Material type name

Max Mass The maximum participating mass (X Mass, Y Mass or Z Mass) for the mode shape. The value isconverted to a force.

Max, MinPrincipal

Principle direction membrane stresses in plates

Member Member name

MemberLoads

Number of member loads in the service load case

ModalMethod

Method used to analyze for mode shapes

Mode Mode number

Modes Used Number of modes included in a response analysis

Moment The semi-rigid connection moment value. Advanced level only

Mx Torsional moment in a member

Mx, My Distributed moment on local x or y face of plate

MX, MY, MZ Nodal reaction moment in the global X, Y, or Z direction, Distributed plate bending momenttransformed to global directions

Mxy Distributed twisting moment on plate edge

MXY Distributed twisting moment transformed to global directions

My, Mz Bending moment in a member about local y or z

Name Name of the Design Group or Mesh

Nodal Loads Number of nodal loads in the service load case

Node Node name.

Normal Direction of vector perpendicular to a plane (e.g. area or plate)

Offset Distance from the starting end of the member, for loads or results.

Offset y,Offset z

Member centerline offset in the local y or z direction.

One Way Normal, tension-only or compression-only member or spring support

ColumnHeading

Description



Parameters Are design parameters set and valid?

Path Hierarchical category for shape or material from the database

Phi Angle to the global Z axis for a spherical coordinate

Plane Top, bottom, or mid-plane of plate element

Plate Plate name

Plate Loads Number of plate loads in the service load case

Points Number of data points in a design spectrum

Poisson Poisson's Ratio, n

Pressure 1 -Pressure 4

Plate pressure load at node 1 through 4

Projected Is the load on the projected length?

Power Semi-rigid connection power factor, advanced level only

R Distance from the origin in polar coordinates

R. Mass Lumped rotational mass

R.FX, R.FY,R.FZ

Sum of reactions in the global X, Y, or Z direction

R.MX, R.MY,R.MZ

Total moment about X, Y, or Z of reactions, taken about the global origin

Result CaseName

The name of the result case for a specific load case.

Result Type Indicates the type of the result case (1st order, 2nd order, or dynamic time results)

Results Load case has valid analysis results?

Rho Spherical coordinate

RX, RY, RZ Rotation in the global X, Y, or Z direction

Rx1, Ry1,Rz1

Rotation release, local x, y, or z at the starting node

Rx2, Ry2,Rz2

Rotation release, local x, y, or z at the ending node

Scale Factor A load factor applied to an entire load combination equation. (e.g. .75 in .75(1.4D + 1.7L + 1.2W))

Section Section name of a shape in a database

Self Weight Includes self-weight of model

Self X, Y, or Z Factor on self-weight in the X, Y, or Z direction

Service Checked for design serviceability

Shear Ay,Shear Ay

Shear Area, area that participates in shear resistance (i.e., the web on a wide flange) Ignored if zero.

ShearModulus

Material property, G, a function of Elasticity and Poisson's ratio.

ColumnHeading

Description



Sigma x,Sigma y

Membrane normal stress perpendicular to the local x or y face of a plate

Sigma X,Sigma Y,Sigma Z

Membrane normal stresses in plates transformed to global directions

Span/Dy,Span/Dz

Ratio of member element length to local deflection in the y or z direction

Spring Spring support name

Stiffness Stiffness of spring

Stiffness 1,Stiffness 2

Semi-rigid connection stiffness parameters, advanced level only

Strength Load case is checked for design strength. Concrete or masonry material compressive strength.

Sy(+z), Sy(-z)

Section modulus about local y, at the extreme z fiber

Sz(+y), Sz(-y)

Section modulus about local z, at the extreme y fiber

T Delta Change in temperature on a member or plate

T Gradient Gradient temperature through a member or plate

T(sec) Period of vibration in seconds

Taper Depth Depth of member at end of taper

Taper End Distance from the start of member to end taper

Taper Start Distance from the start of member to begin taper

Taper Type Type of member taper

Tau Principal Principal shear stress in a plate

Tau xy In-plane shear stress on a plate

Tau XY, YZ,or ZX

Membrane shear stresses in plates transformed to global directions

Therm.&alpha

Thermal coefficient of expansion, greek character, alpha.

Theta Theta Angle. Used in polar or spherical coordinates.

Thickness Thickness of plate element

Time The time for a time-history result case, this may be a time-step or an actual time in seconds,advanced level only

Type Type of spectrum. Design code or specification.

Unity Unity check ratio (<= 1 is good, >1 is bad), or actual value/allowable value, or demand/capacity.Used for forces, moments, stresses, deflections or other criteria.

Vx, Vy Distributed shear force on x or y face of plate

Vy, Vz Shear force in the local y or z direction in a member

ColumnHeading

Description



WarpingConstant

The warping constant, Cw, a property of the cross section of a member element, advanced level only

Weight Weight of member or plate

Weight-X, Y,or Z

Self-weight of the model in the X, Y, or Z direction

X C.M., Y, orZ

X, Y, or Z location of the center of mass

X Cosine, Y,or Z

Spring direction cosine in X, Y, or Z

X Dir, Y, or Z Direction factors for a Response Case

X Mass, Y, orZ

Contributing mass in the X, Y, or Z direction for a mode shape. It may just be a small portion of themodel that is vibrating. The mass is converted to a force.

X Part, Y, orZ

Modal Participation factors in X, Y, or Z, represents the percentage of structural mass that is 'active'in a mode shape. Building codes often require that you include enough mode shapes in a responseanalysis to achieve a certain level of participation.

X, Y, Z Global Cartesian X, Y or Z position in space

X1, Y1, Z1,X2, Y2, Z2...

Global coordinate for node1, node2, etc. for member or plate. Or vertices for areas.

ColumnHeading

Description

6.5 Member GraphsMember Graphs display detailed moment diagrams, shear or deflection diagrams for members. They show the resultsfor one member (or chain of members) and one load case at a time. Create Member Graphs from the context menu,after selecting one or more members in a Result View. Note that the Result View (Section 9.8) can also display on-frame diagrams for all the members at once, using Result Filter options. The member graph view is a more detailedand sophisticated presentation.

Create a Multi-Member Graph

You may create a single graph for a chain of member elements. Select two or more connected members that form aline, and have commonly aligned local axes. An example is a girder with beams framing into it. The girder is typicallysplit into separate elements where the beams frame in. After selecting the members in the Result View use the ContextMenu to choose Member Graph.

Customize a Member Graph

Use the Filter tab to change which plots are included, or which member is reported. You may also change otheroptions such as whether data points or annotations are displayed and line and font options.

Print a Member Graph

Use File | Print Preview. You may wish to set a landscape mode first using File | Page Setup.

Export a Member Graph

To export a Member Graph from VisualAnalysis for presentation in another program, choose Home | Copy to paste acopy of the active Member Graph to the clipboard. Use Home | Paste insert the picture into almost any otherapplication.



7 Succeed

7.1 History

7.1.1 Version HistoryAre you upgrading from a previous version? Read about What has changed and Why!

Version 17.0 (Section 7.2), March 2017, 64-bit, C#, .NET, WPF, .XML custom dataVersion 12.0 (Section 7.1.2), February 2015, miscellaneous, optional 64-bit versionVersion 11.0 (Section 7.1.3), January 2014, design specifications updatedVersion 10.0 (Section 7.1.4), December 2012, Ice-wind loading, stress-checks, VAConnect linkVersion 9.0, November 2011, Automated validation (improved accuracy & correctness)Version 8.0, October 2010, VisualDesign & VisualTools incorporatedVersion 7.0, October 2009, Areas, Rotation Cube, Reporting improvementsVersion 6.0, August 2007, OpenGL true 3D graphics, Performance-TuningVersion 5.50, July 2005, K-factors, XLS report, Wood SCL checks, CISC designVersion 5.10, November 2003, Semi-rigid ends, cable elementsVersion 5.00, December 2002, February 2003, Proprietary C++ Analysis EngineVersion 4.01, December 2000, design specifications updatedVersion 4.00, June 2000, Project Manager, Added .dbs/.dbm customizable databasesVersion 3.50, November 1998, Microsoft MFC, split plates, load combination templatesVersion 3.11, November 1997, VisualToolsVersion 3.10, September 1997, VisualDesignVersion 3.00, December 1996, 32-bit Windows 95 version, C++,Version 2.50, September 1995, VisualStress, VisualSteel, VisualConcreteVersion 2.10, June 1995, smart naming, custom shapes, 3D rotation, CQC dampingVersion 2.00, December 1994, first suggestions from practicing engineers!Version 1.00, May 1994, first commercial release, 16-bit, C++, Borland OWL, Ported SAP IV Engine

MSU WinFinite

WinFinite was a non-commercial product, developed by future IES partners, at Montana State University. This was thebasis for VisualAnalysis when IES, Inc. was formed and the technology was licensed from the university. Copies of thisproduct were given freely to engineers licensed and living in the state of Montana as well as to CH2M Hill, Inc. forsponsoring the research that went into its development. IES returned over $100,000 in royalties to the university tosupport structural engineering education. True to our roots, IES has provided free educational software to schools andstudents since 1994, see edu.iesweb.com for details.

Version 1.50, January 1994Version 1.00, January 1993

7.1.2 Prior Version 12.0

IntroductionThis upgrade is an incremental step forward to improve your productivity and eliminate minor trouble-spots prior to amajor rewrite of VisualAnalysis that is expected in the next upgrade cycle.



http://edu.iesweb.com/

Added Features

Concise Member Force and Displacement report tables (one line per member!)Member Graphs: cleaner look, easier to use, filter improvementsSteel Design per CSA S16 (2014)Wood Design allows parametric rectangle and round shapesReport Wizard is smarter about load cases and result casesClipboard Exchange: will now Modify or Delete nodal or member loadsSDNF 3.0 (Steel Detail Neutral File) import / exportCold-formed Steel updated to CFS 8.0Import Custom .scl files directly (right-click on shape database tree)Custom Load Combination: automatically "clones" a selected combinationNodal Settlement loads appear in the Find Tool windowManually editing a Design Group, removes it from the 'Auto-Group' featureImproved diagnostics in Check Model for ErrorsAdded support for VisualFoundation 6.0 features

Optional 64-Bit Version

Good for larger memory-intensive projects: Time History, AISC-Direct, or hundreds of Load Combinations might exceedthe 2GB (theoretical) memory limit of the 32-bit version. The 64-bit version does have some limitations, so you maynot want to use it for everyday projects.

No STAAD import/export featureNo SDNF import/export featureNo Cold-Formed Steel designNo performance improvement over 32-bit versionYou *may* install both versions on a 64-bit machineNot included in the IES Updater list, install updates manuallyDoes not automatically open .VAP projects from Windows Explorer: right click to use Open With

Fixes or Changes (since version 11.0)

Parametric I-Beam, plastic modulus was incorrectly calculated for steel design (by 10-15%)Missing toolbar problem eliminatedProject Manager remembers it's width on exit/restartFind Tool window remembers it's height on exit/restartFind Tool window uses more concise member result tables (one row per member)Overlapping member loads (linear and/or uniform) are detected in various placesResult tables default to 'extreme rows only' (use Tools | Preferences, Reports to change default)Parametric Angle shapes were reporting Geometric rather than Principal stiffnessEditing table column unit-precision was not working properlyDouble-click result report is no longer the "Complete Member" reportFootnote added to "Member Extreme Results" table to explain load case numbers in ()'sSTAAD (.std) Import, would not read Steel database shapes properlySTAAD and SDNF commands have their own menu-items.Split Member might sometimes "mess" with Design GroupsTime-History analysis now works properly with one-way membersFixed AISC shear check on double-angle shapesFixed Aluminum combined stress ratio bug fix



Wood design reports now show the full material nameAluminum design: more intermediate values are reportedClipboard Exchange: minor improvements to display in dialog box

Removed "Features"

Customize member graph option in Filter (confusing, settings would randomly change)Ability to persist custom member graph settings across VA sessions (didn't work well)Saved window layout (toolbars would go "missing" far too regularly)


IntroductionOur primary focus with this upgrade is to keep you current with updated design specifications and building codes. Oursecondary concern is to smooth out some rough edges and refine the product so that it works smoothly. While we haveadded a few new features designed to improve productivity, there is a major ongoing effort behind-the-scenes at IES tocreate the "next" big platform for VisualAnalysis.

Major Added Features

IBC 2012 Load CombinationsSteel Design per AISC 360-10 (14th Ed.)Wood Design per NDS 2012Concrete Design per ACI 318-11Cold-formed steel design per NAS 2012 (CFS 8.0)Rotate Views about a selected node or memberEasier Node-Dragging/Member Extension in "Draw Nothing" modeAuto-Mesh by Area for more fine-grained control of plate meshing

Other Added Features

Improved Help File layout, searchArea color added to preferencesUpdated Shape & Material DatabasesDesign Results report lists all members in a group (and those unchecked)Generate Copies is 10,000 times fasterProject Summary Report shows Building Code Load Combinations usedWorks with VisualFoundation 5.0Works with VAConnect 2.0Importing Load Cases through Clipboard Exchange is infinitely fasterMember Graphs with Moving Loads are vastly improvedDesign material is displayed alongside Design parametersConcrete Beam design adds a deep-beam checkSteel Single Angle design is more accurate

Miscellaneous Fixes

Toolbar-layout is no longer customizable (because restoring them failed too often)Rotating a model, Area span directions are now correctWire-frame overlay no longer obscures results in a Result View (Picture View mode)



Fixed memory-leak when switching among Result Cases (in Picture View mode)Semi-rigid end connections are now displayed graphically (with Filter option)Mirror-copy would fail to copy triangular plates properlyImproved display of reaction labels near plate elementsOpenGL graphics improvements n Model ViewCorrected issue with 'Shear Tab' design groups getting renamed after opening a project file


IntroductionWelcome to VisualAnalysis 10.0. The engineers at IES have worked hard to implement many customer-suggestions forimproving and extending the software. We attempt to do this without disrupting the normal work flow for long-timecustomers and without over complicating the product. Most new features are optional and fairly isolated items or arejust natural extensions to help you work more quickly and easily.

Major Added Features

Ice + Wind Loading on Members (Design level)

Benefit: Allows you to design “open” (e.g. lattice tower, bridges) structures more easily.How: Apply either of two new load types to member elements. VisualAnalysis automatically calculates iceweight given a thickness, and wind pressures on the surface area of member (or member + ice) as afunction of height (per ASCE 7). New load sources Di, Wi are available for these types of loads and areincluded in load combinations.

AASHTO Load Sources

Benefit: More straightforward application of AASHTO for load combinations and results.How: There is a preference setting to select types of load sources to generate in your projects. Applyloads in newly named load cases, and create or import custom load combinations according to AASHTOrequirements. (Load combinations for AASHTO are not really automated in this release.)

Stress Checks (Generic) (Advanced level)Benefit: Quick member stress-limit checks for any shapes or materials or for design codes andspecifications not provided in VisualAnalysis. Allows you more code-flexibility.How: There is a project setting to group members for stress checks in the design criteria. In the designview you may have or create design groups for member elements. You specify stress limits(tension/compression) and software checks all the results for you.

Copy Multiple Loads from Member to Member

Benefit: Easier ways to generate your loads on members.How: Select all the loads on a member, copy & paste to another member or group.

Integrated Steel Connection Design (Design level, through IES VAConnect)

Benefit: Huge time saving feature and sophisticated calculation for column base plates (with ACIAppendix D anchorage calculations) and shear-tab connections for beams. VisualAnalysis assembles andexports all the connection data to VAConnect utilities (installed and purchased separately).How: Possible connections are shown in the Design View, grouped automatically. You can manuallyadjust connection-grouping and then select a group to export your geometry and results to either theBase Plate or Shear Tab tool for design. A report is saved and available in VisualAnalysis for review andstatus indicators in the graphics help you keep track of which connections you have designed already.

Import Loads into Multiple Load Cases



Benefit: More flexibility for very complex loading situations.How: Use the Home | Clipboard to import loads into specific cases.

Engineering Features

Override K-factors for steel design when using AISC Direct Analysis methodTop of Steel feature integrates better with manual member centerline offsetsWood Cc (curved glulam) override setting allows smarter designDeflection limit preferences save you timeRigid Link results are available in Result View (optionally)Beam Deflections report table (post-processed analysis displacements for beams)Tapered Member stress checks (via generic stress check)Design Group table reports controlling load combination (report and Find Tool)Metric rebar option is now a project-setting (Modify tab for Project Settings), there is also a preferencesetting.Cable elements show initial Sag in Modify tab

Functionality and User-Interface Features

Improved graphicsHighlight Report viewing mode (selected items shown 'normally' others are 'ghosted')Editing in Project Manager is much improved (far fewer clicks required!)Undo/Redo for design groups is friendly for accidental changesNew color preference settings gives you more control over graphicsMember result colors are much cleaner in picture view modeArea Sides report (and Find Tool) tableMember Graph customization is easier to accessWarning to prevent very long reports (customizable limit)

Advanced Level Features

Autodesk Revit 2013 support (see the Supplementary downloads page at the web site)

Minor Fixes

Performance improvements and robustness for scissor nodesMember connection forces report truncation of data was fixedRotation menu & toolbar tips are correctWood CF fixesBill of materials reporting of glulam board-feet improvedExit application is allowed when Report View is activeWood design deflections are improved (scaled with E)Improved unit-conversion factors for obscure unitsMath expressions in edit controls work properly with a leading negative valueFixed repeated error messages when importing from STAAD filesUnity checks would report failure for 0.3% over 1.0, adjusted default limit.When unity checks are suppressed, there is a watermark in the Design ViewWhen unity checks are disabled for a group, the report and help-pane indicates thisClipboard exchange export list of load cases no longer shows empty cases.

Features Removed



The base-plate design report wizard was obsolete and has been replaced by IES VAConnect integration.

7.2 Version 17.0 Upgrade Guide

IntroductionWow. From the inside-out, we have mostly rewritten this tool using the latest technologies, hindsight, and lots and lotsof customer feedback. From the outside-in, we hope that longtime customers are as comfortable in this version as inprevious versions. We also hope you'll spend less time getting work done--fewer mouse clicks, blazing performance,easier to understand commands, and more accurate engineering. And "No", you didn't miss anything we jumped theversion number dramatically from 12.0 to 17.0, for several reasons, but there was no version 13, 14, 15, or 16.

Licensing

If you are running an active license for VisualAnalysis 12.0 (not expired) then this version should "just work". With anetwork license you may need to enter the path to your license-share folder. If your VisualAnalysis license has expiredprior to the release-date of version 17.0, you will need to purchase an upgrade in the self-service portal, or bycontacting IES Sales.

Legacy Projects

We have successfully imported hundreds of old .vap projects into the new system, but we have also seen dozens ofissues or problems, some of which are not easily resolved. There have been many changes, for very good reasons.Member shapes may 'rotate' to their principal orientation from a legacy project. Most issues are handled automatically.

Some projects may not open. If you find one, please send it to IES Technical Support, then continue to use version 12.0for that project, until we resolve the issue.

If you get an error message telling you to install VisualAnalysis 12.0, please download it here: setup-va12.exe. Install it. Open your legacy project file. You may then safely uninstall version 12.0, the legacydatabases will remain in place.

Major Changes

We understand that changes can be disconcerting. We have worked hard to balance innovation with respecting ourmany long-time customers. Our hope is that you will embrace the changes, and adapt to them quickly. We think mostwill make the program much better moving forward. The rest we'll fix, after you tell us what went wrong.

Main Menu

Gone is the old menu with separate toolbars. The new main menu (Section 1.3) (ribbon) is easier to use, but a littledifferent. We think you'll grow to love it within a few days.

Mapping from Your Model to FEA

We now completely automate the creation of the actual FEA model from yours. When it is time to analyze we checkyour model, and then construct a correct FEA model from it. If there are errors or warnings you will find those in theResult View, or a Model Check.

This means that we will automatically split and connect member elements (Section 2.4) so you do not generallyhave to worry or think about member elements vs. girders or multi-story columns. Model the members in a way thatworks best for you. You can split or merge members, and cross them. The trick to the new system is a memberproperty called Connect Crossings which is defined per-member, but the default is Yes. You should generally allowmembers to connect. The most common exception is for X-braces, where you typically should not connect them. If youare getting strange instability warnings, make sure this option is turned on for your members!



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https://www.iesweb.com/ftp/install/archive/va12/setup-va12.exe

https://www.iesweb.com/ftp/install/archive/va12/setup-va12.exe

New Databases

If you created custom shapes or materials in ShapeBuilder 6.0 or directly in VisualAnalysis 12.0 (and prior versions),they will not be available in version 17.0. Those older products used a different database system. You will needto manually recreate those custom databases in the new system. Please see the Shape Database (Section 1.10)and Material Database (Section 1.11) topics for details.

If you created Custom Building Code Load Combinations, you will need to re-create those in the new system. Yourold "CodeCombo10.txt" file in your Custom Data (Section 1.9) folder can be used to help you re-enter the data intothe new system. This only needs to happen once. You can copy the new database to other machines!

The shape database now contains Virtual Joists and Virtual Joist Girders which are developed by the Steel JoistInstitute. Their website has information on the basic concept and purpose. You may create models with these shapes,and get steel design-checks as if they were steel beams.

Structure Types

Everything in VisualAnalysis 17 is now based on a space frame structure definition. We removed the academic plane-frame and plane-truss. Why?

Greater reliability (far fewer combinations of things to test)Plane structures had unrealistic limitations (like, no shape rotation, no out-of-plane bracing)It is still easy to create plane trusses or plane frames! (Shift+Click a node, fix all the Z-supports(Section 2.3)!)

Section Coordinates Clarification

VA 12.0 had some issues dating back to the 1970's and 1990's with regard to the way member cross-sections weredefined. In VA 11.0 we clarified the major-principal axis orientation, which many engineers discovered when usingsingle-angle shapes.

When upgrading legacy projects to VA 17, shapes that are wider than tall, or where Iy > Iz, will get rotated.You can fix this using the beta angle. We don't try to do this automatically because the beta angle also affectsend-releases and loads that you may need to address.

Still at issue were inconsistencies in the geometric coordinate systems (e.g. x-y in the AISC manual), the principalcoordinate system (often labeled as 1-2), and a member element's (Section 2.4) local coordinate system (in VAthis is z-y, because x is always along the length). These three are all related, but not always lined up the way you mightexpect. It has serious implications for orienting shapes, interpreting member results, and understanding what is meantby "Top" or "Bottom" in concrete beam design (Section 5.10)!

In VA 17.0 all member shapes are oriented according to their principal axes for analysis. Custom blobs are defined byI1, and I2, not Iz and Iy. The rule for section orientation is now this: The shape's major principal 1 axis is alwaysaligned with the member element's local z axis.

Because of this change, we will not import Concrete Design groups "correctly" in all cases, so we do not try. You willneed to think about member orientations, and may need to set the Beta angle to orient the member correctly for Topand Bottom terminology.

Background Analysis & Design

Where is the Analyze button? We put your computer to work for you, without slowing you down or degrading theperformance of other applications. Trust us! As you build your model we start checking, analyzing, and running unitychecks. If you make changes, we start over. The result is this: when you want results, they are generally alreadyavailable, or you wait a lot less. When results are not available view the expandable Status panel in the ResultView will show information or errors.

Removed "Features"





Once in while, features get lost or removed. We take things out to simplify the software or eliminate problems. If one ofthe following was really important for you, please tell us through a technical support email what you want to do andwhy. No guarantees, but we do operate a customer-democracy, not a developer dictatorship!

Explicit structure type for: Plane Frame, Truss, Grid (still easy to do, see above)Combined Members: Simplified, see Connect Crossings (Section 2.4)Analyze Button (see Background Analysis above)Saved/Named Views (rarely used, marginally useful, this may return in some form in the future)Most preferences for Filter settings (ask for specific ones, as needed)Named Color preferences (named colors are generated and assigned automatically)Bill of Material Costs: removed dollar values, formwork, board-feet, connections (a simple material take-offremains)Rigid Diaphragms (use plates (Section 2.5) to model diaphragms, more accurately)Spreadsheet Report (use: Save As .xls, then use Excel!)Email Support (did not work for many email clients)

Major New Features

System

64-bit Architecture for large projects, advanced analysisNotification system for IES critical messages to customersDirectX Graphics (replaced older OpenGL system)Shape (Section 1.10) & Material Databases (Section 1.11) have changed format

General / User Interface

Ribbon Menu/Toolbar with smart sizing, great tooltips, easier to useGraphic View tabs moved to top, more windows are tabbed viewsStatus panel for errors or other information about your projectHot-Keys (shortcuts) for most commandsAdded radian units for rotational stiffness termsCreate tab has more optionsQuick color-themes for graphicsSimplified preferences, with better limits and helpAutomated 'settings', like preferences, remember the last setting you used)

Graphics / Filters

Hover-highlighting in graphicsNamed Colors are assigned automatically (no setup required)Sticky-Notes may be placed on Graphic ViewsSmarter Selection with Object Keys (e.g., M for Member)Revit-like "Tab Selection" among objects hovered overRotation about selected line objectsSnap-points along edges or members for drawing

Modeling

Smarter, faster plate meshingPlate elements now offer moment-releases



SJI Virtual Joist and Joist Girder tables for member propertiesSmarter naming systemCombined members are managed automatically ('connect crossings')Area Sides are optional, add them to specific edgesImport DXF Circles, Ellipses, Solids and Closed PolygonsClipboard Exchange is now "units" aware and more completeCheck Model for Errors runs automatically in the backgroundModel checking is more sophisticatedFaster, more flexible ways to create nodes

Loading

Sortable lists in Load Case ManagerWind load project-wide settings are easier to accessPreference for load direction arrow directionsScale all loads in a service case

Analysis

100% background analysis (ready when you are)View partially-converged results during 2nd-order analysisAbility to perform a Buckling or Pushover analysis (via partial results)"Mode Shape Cases" for multiple-frequencies in Dynamic Response analysisSkip certain frequencies for Dynamic Mode ShapesDynamic Response analysis produces a Base Shear result

Results

Displacement amplification option addedResult validation is automatic on every analysisFaster post-processingPlate-mesh Moment & Shear diagrams (drag a line graphically)

Design (w/Design Level)

Improved accuracy for stresses and deflectionsSteel single-angle, double angle and tees are more accurately checkedImproved support for custom and parametric cross-sectionsMany Concrete Slab design improvements (flexible rebar, optimize rebar, minimum checks...)More accurate/robust calculation of wood Load Duration factorsPerformance improvements (members checked in parallel with multiple processors)More control during Design Optimization (search)More control over Quick DesignChoose a "Check Level" to balance performance with preliminary design/reportingAluminum heat affected zones

Reporting

Use a Custom Logo in Header (same as ShapeBuilder or VisualFoundation)Concise result tables are available



Report Templates (formerly called Styles) are better managedClick to Sort table columnsDrag to Resize table columnsEasier Add/Remove for tables and columnsBetter report viewer (preview, zoom, thumbnails, etc.)Export to clipboard, comma or tab-delimitedSave to more file formats (.pdf, .xls, .docx, etc.)Reporting performance is dramatically improved

Advanced Level**

P-Delta is available for Time History analysisMoving loads on "member chains" with reduced restrictionsMoving loads: lane loads create results on all model objects (not just members)

Bug Fixes (since version 12.0)

Many, many fixes. Hundreds actually.

See Also: Version 12.0 Changes (Section 7.1.2)

7.3 Support Resources

Did you Search this Help File?

Be sure you make use of the help and support built into the software (Section 1.3), as described in theEssentials (Section 1.2) section of the User's Guide. This document may be searched, and you should try differentpotential terms, sometimes less is more when searching--use just the unique word or words! There is also a logicalTable of Contents available.

Do Not Contact Support For:

Licensing or Sales: use www.iesweb.com/service or [email protected] about how to model a particular structure. Such questions are your responsibility as an engineer.IES cannot validate your model or your results. If the "seem" incorrect, please figure out WHY they areincorrect. If you can document a defect, we will be happy to investigate deeper and fix things as necessary,but we cannot afford to check every customer's model.Questions about engineering theory. IES is not in the business of educating engineers. There aretextbooks referenced in this help file and we can provide more guidance as to where to look if you cannot findone.

Technical Support

Support Email: [email protected] (Replies are usually within 2 business hours, if you don't hearanything within a day, assume it got spam filtered or lost and follow-up! For best results be sure to ask aquestion, indicate exactly which IES product & version you are using, include as much detail as is practical orrelevant, including attaching a project file. "I have a problem, can you help?" is a frequently submittedquestion, to which the answer is always: "Maybe, what is the problem!".Support Telephone? No, sorry! We have found this to be too inefficient for everybody. With email you canattach a screen shot, a project file, and we can better direct your question to the IES expert for that productor area. Phone 'tag' takes longer than you think.



https://www.iesweb.com/service

mailto:[email protected]


Business Questions: For any licensing or sales-related questions or issues: [email protected].

Free Training Videos: See the Table of Contents in this help system!

7.4 Improving PerformanceVisualAnalysis algorithms are fast by design. Your computer can execute billions of instructions per second. MostVisualAnalysis models you create will analyze in less than 2 minutes and produce reasonable reports. However, just likewith any tool, you can get in over your head and become a slave to the machine, waiting literally HOURS for things toprocess. Please do not let this happen to you.

Most VisualAnalysis customer models contain far less than 10,000 nodes and 150 load combinations. If you model mightapproach either of these values, then you should really think about performance long before you start modeling.

Background Processing

When you make changes to your project, VisualAnalysis will show you a progress indicator in the status bar, showing itis doing some work in the background. You do not need to "wait" for this! VisualAnalysis takes advantage of thefact that your computer is sitting idle 95% of the time. We use multiple-threading to get some work done. This will notslow you or your other programs because the threads are separate and given low priority. You may use Windows Taskmanager to monitor how your processor (and all of its cores) are used, and when, and by whom.

Divide & Conquer

Build a model that answers only the questions you need to answer. You might need different models for differentquestions.

Think about what you want to learn from your model, then model only the essential components. If you can split yourstructure along a line of symmetry, or at an expansion joint, or otherwise, it might save many hours. Working with afew smaller models can be significantly faster than working with one gigantic model.

Processing time increases on the order of N^3, where N is the number of nodes in your model.

KISS Modeling

You have likely heard the phrase: "Keep it simple, stupid." When modeling your structure think first, sketch later. Startwith the fewest number of elements to accurately model the geometry and boundary conditions, especially with plateelements. Then refine from there, as needed.

Graphics Hardware & Options

Picture View mode can be more expensive than drawing without it, especially in a Result View, where displaced shapesare drawn with stress colors.

Your video card hardware can have a significant impact on graphic performance. VisualAnalysis utilizes Microsoft'sDirectX graphics system. If you experience poor performance, graphical "artifacts" such as stray lines, unusual blocks ofcolor, fuzzy text, or similar usability issues, you should investigate or update the video card and drivers. There are awide range of hardware manufacturers, but the cards are usually based on chip-sets from one of three majorcompanies: NVIDIA, ATI-AMD, or Intel. We have found that most video cards for PCs work just fine. Laptops or tabletsmay have much lower-quality and/or performance.

We have seen very poor performance from NVIDIA Quadro series cards, which are common on 'workstation' typemachines.

Your mouse and mouse driver could also impact performance and behavior to some extent (middle-mouse buttonconfiguration and mouse-sensitivity settings, etc.). There is a known issue in Microsoft code that affects certain mousedrivers and maximized windows--if you see strange crashes that do not happen if your window is not maximized, youmight try a different mouse.




Advanced Analysis

The fastest analysis is a first order analysis with a linear model. P-Delta is more expensive. Direct Analysis adds loadcombinations and more iterations. Moving Loads and Time History analysis can be very time consuming.

Prune Load Cases & Combinations

Analysis, design, and reporting are all directly impacted by the volume of results. The Live Load Reduction feature willadd additional load combinations. The Direct Analysis Method adds "Notional Loads" and therefore more loadcombinations.

Before you add 10,000 loads in 35 load cases with 200 load combinations, check to see that your model is stable underself-weight and then proceed. If you are using automatic Building Code combinations, you might end up with many"redundant" load combinations, ones that you know will not control. The computer program cannot make this judgmentand blindly assumes any one of them could control. It pays big dividends to get rid of extraneous combinations, not justin analysis and design time, but also in report size! You can perform this pruning in the Load Case Manager, on theCombinations tab.

Performance vs. Accuracy Settings

With numerical solutions, answer are always approximate and oftentimes calculated at a number of discrete points. Youcan reduce the number of places where this happens, balancing between performance and accuracy. VisualAnalysisprovides an easy place to manage these settings: Project Settings, Performance.

Hardware: CPU & Video Card

Most desktop computers have faster CPUs, video cards, and other systems. Laptops can be very low-end. Upgradingyour machine can potentially have a big impact on your performance.

See also: Analysis Performance (Section 4.4)

7.5 My Model is UnstableSome of the connection problems discussed above result in mechanisms (structures that have moving parts), but thereare other ways to create mechanisms in a VisualAnalysis model. Some of these are obvious once you "see" the problem.Others are more subtle mathematical instabilities that would not happen in a "real" structure, but cause problems in thematrix analysis.

Plane Frames or Trusses?

VisualAnalysis uses a space frame structure type, with six degrees of freedom. To stabilize a planar model, simplyShift+Click on a node and fix all of them in DZ (or your out-of-plane direction).

3D Instability

When trying to analyze models in 3D it is common to get instability because of either (a) forgetting about the out-of-plane direction, (b) forgetting about rotations, or (c) having simply too many end-releases and/or not enough support.You can debug your model in this fashion:

1. Start with just one or two load cases for speed2. Check that each member's Connect Crossing setting is set to Yes (default), except for X-braces.3. Remove ALL the member end releases (shift+click a member), except perhaps simple beams. 4. Is your model stable for analysis under both dead and lateral load? reasonable displacements?5. If so, add end-releases carefully, only add releases where you need them. (If you don't have weak axis

bending, you don't need weak axis releases!)6. Repeat step 5, as necessary to eliminate moments you do not want or expect.



PROBLEM: Rotating Columns

When modeling a braced frame in 3D you will often have columns that are pinned at the base, supporting simplebeams, and possibly bracing members. This is how the structure is built, but your model is a mechanism. Typically youwill model this with end releases on all the beam members because you do not want them to carry moments throughthe simple clip angle or shear tab connections.

SOLUTION:

This can result in confusing messages from the analysis engine! The explanation is that the entire column is free torotate about its own axis. The pin support at the base provides no rotational restraint, and if all the beams have weak-axis moment releases, then they provide no resistance to this rotation either. The error is in modeling the connection tothe foundation, which will not rotate. Fix the column base with a nodal support in the RY direction.

PROBLEM: Four-Node Truss Panels

Perhaps one of the most embarrassing problems you will face in structural modeling is when you create a situation thatyou know is unstable from your first structural analysis course in college. Everybody knows that a truss is made out oftriangles and that a four-node truss panel is unstable. And yet, it is easy to create a 3D space truss like this:

SOLUTION:

The solution is to look at the structure from the end. Now you can see the four-node truss panel. The solution dependson the structure you intend to build. Most real structures are not pure trusses, but will carry moments. You may alsowish to provide some knee braces or similar supports.

PROBLEM: One-Way Members are Removed

Another mechanism problem that you can run into in VisualAnalysis is not really a problem with your modeling, but inthe non-linear analysis of tension-only or compression-only members or spring supports.

When you analyze a model with one-way elements, the analysis is iterated. Elements are checked after each analysis todetermine whether they need to be removed or put back. This continues until the solution converges—that is, noelements need to be removed from or replaced in the model. Unfortunately, you do not always get convergence andyou have to resort to manual solutions or modeling changes.

Sometimes however, you can end up with a different type of problem. Because elements are removed from the modelautomatically, and somewhat randomly, your model can become unstable. The following simple structure demonstratesthe problem. The diagonal brace is defined as tension only, but the load will put it in compression so it will be removedduring analysis.

SOLUTION:

The trick is to remember that you have these one-way elements. Mark all of your one-way elements to behave normally(perhaps in a copy of your project file) and see if the analysis will run in a linear fashion. If so, you are closer to solvingit. The solution though, may be involved and is placed under the heading "The Art of Modeling"; in other words, IESTechnical Support is not going to help you solve this one!

7.6 Validate Your Results

Before You Analyze

Before you perform an analysis, you should carefully check all input data. You should always use the Tools | ModelCheck command. You still may want to manually note that features like end releases and support conditions arecorrect. You may also want to take a look at the Picture View to visually observe member sizes, member materials,orientations, and locations to ensure they are correct.

In a Model View you may also want to check the local axes, beta angles, and other properties using the Modify tab (asan inspector) or the Filter tab options. Use the Find tool to sort objects based on any property shown in a column—



mistakes tend to float to the bottom or top of the list!

Reports are available to record the data you have entered and provide another way to find mistakes. Refer to theReporting section for more information about reports.

Total Load Checks

One of the first checks that should be made after an analysis is to verify your total structural loading. Use the Resulttab of Project Manager to see the Statics Check for each load case. The applied loads are totaled in each direction.

This information is also available in a statics check report. Included in this report will be the total load applied to thestructure in each global coordinate direction for each load case. Check these numbers against an estimate of the actualloads applied. Verify that the reported totals are in the ballpark with your estimates. If there is a discrepancy use theModel View to verify load directions and magnitudes.

Static Checks

The Statics Checks are available under the Result tab of Project Manager or in a Report View will help you find manytypes of problems.

Check for nearly unstable structures. If you have poor geometry or very flexible members in critical areas, the structurecan be on the verge of collapse due to instability. Many times unbalanced reactions can be a tip-off for these problems.This imbalance is automatically checked at the end of the analysis phase. You might receive a warning message if theStatics Check imbalance is significant.

Displacement Checks

Look at the deformed shape of your model. Does it make sense based on the loading and structure? Remember thatthe displaced shape is usually exaggerated so you can see it. For true displacement display use a zero for the DisplacedShape Factor in the Filter tab for a Result View.

Look at the magnitude of the largest displacement shown using the Result tab in Project Manager. Is it large? Ifdisplacements are too large the basic assumption of small displacement is violated and results must be questioned.

Reasonable Stress Checks

When you are comfortable with the loads, statics, and displacements you should also check stresses. Use the Filter tabfor a Result View to show stress values and the legend. Look at the extreme value presented in the legend. Are thestresses reasonable? The software will blindly place 1,000,000 ksi on a wood member without warning! Would you? Itonly takes a second to zoom in on the extreme color and see where it exists. Make a decision as to whether or not it isreasonable.

Validation is Up to You

Finally, use your experience and engineering judgment. If something just does not look right, investigate it carefully.Convince yourself that the results are correct before continuing.

Getting correct results is up to you as an engineer. We make every effort to test the software but it is impossible toprove it correct under all circumstances. If you have a problem please investigate it carefully. Compare the results withanother program, hand calculations, or estimates. Before you contact us please prove to yourself that there really is aproblem in the software—we do not provide consulting support, or "model checks" for you.

If you find an error giving you incorrect results we want to know about it! Carefully document the problem and thencontact us using the support channels outlined in the Troubleshooting chapter or on our web site. IES is committed tomaintaining a high quality tool in VisualAnalysis. We stand behind the software and will work quickly to solve anyproblems you might expose.

7.7 Legal Stuff



Intended for Engineers

VisualAnalysis is a proprietary computer program of Integrated Engineering Software (IES, Inc.) of Bozeman, MT. Thisproduct is intended for use by licensed, practicing engineers who are educated in structural engineering, students inthis field, and related professionals (e.g. Architects, Building Inspectors, Mechanical Engineers, etc.).

The results obtained from the use of this program should not be substituted for sound engineering judgment.

Although every effort has been made to ensure the accuracy of this program and its documentation, IntegratedEngineering Software does not accept responsibility for any mistake, error, or misrepresentation in, or as a result of, theusage of this program and its documentation. (Though we will make every effort to insure that problems that we cancorrect are dealt with promptly.)

License & Copy Restrictions

By installing VisualAnalysis on your computer, you become a registered user of the software. The VisualAnalysisprogram is the copyrighted property of Integrated Engineering Software and is provided for the exclusive use of eachlicensee. You may copy the program for backup purposes and you may install it on any computer allowed in the licenseagreement. Distributing the program to coworkers, friends, or duplicating if for other distribution violates the copyrightlaws of the United States. Future enhancements and technical support depends on your cooperation in this regard.Additional licenses and/or copies of VisualAnalysis may be purchased directly from Integrated Engineering Software.

Contact Information

Integrated Engineering Software519 E. Babcock St.Bozeman, MT 59715www.iesweb.com

Sales: 406-586-8988, [email protected]: [email protected], (No telephone technical support is provided.)

Copyright and Trademarks

Copyright © 1994-2017 Integrated Engineering Software Inc. All Rights Reserved. VisualAnalysis™, andShapeBuilder™, VisualFoundation™, QuickFooting™, VAConnect™, and VA-Revit Link™ are trademarks of IntegratedEngineering Software, Inc.

7.8 Educational Version

Documentation

This help is for the full commercial product and is not marked-up by the educational restrictions, which are listedbelow.

Outreach



https://www.iesweb.com/



https://www.iesweb.com/

Since 1994, IES has offered a free educational version of VisualAnalysis. This is available for students and facultymembers at institutions in the USA and Canada that offer engineering degrees. Students and faculty should visit edu.iesweb.com for updates, and educational support information.

FAQ

How to model a Plane Frame, or plane truss (Section 2.2)?

Limitations

The educational product is intended for Educational Use Only; it should not be used for profit or consulting work.The educational product is the advanced level of VisualAnalysis, with the following restrictions:

Project Size Limits

Up to 5500 nodesUp to 1000 membersUp to 5000 plate elementsUp to 25 factored load combinations

Restrictions

No DXF file importNo Auto-meshed areas (use manual plate meshes)No Automatic building-code load combinations (use custom combinations)No Design checks, except for steel (limited)No Design 'search' or optimization to resize members

Upgrade Guide

If you previously used version 12 or prior, please read the upgrade guide (Section 7.2) for important changes.



http://edu.iesweb.com/

8 Integration

8.1 IES ShapeBuilder

Section Properties Calculator

Create custom shapes to obtain section properties for analysis or design checks, analyze for stress distribution,transformed composite properties, reinforced concrete stress and strain, and more.

Custom Shapes

Certain custom shapes created in ShapeBuilder can be exported to the Shape Database (Section 1.10) used byVisualAnalysis. You can then build models with member elements using the custom shape. Common steel, wood, andaluminum shape-profiles are generally supported for design-checks in VisualAnalysis. See ShapeBuilder's Help fordetails.

Purchase ShapeBuilder

To buy licenses for ShapeBuilder, please visit the web site or call us.

8.2 IES VisualFoundationRequires: IES VisualFoundationThere are two independent ways that VisualAnalysis and VisualFoundation can work together to help you solveproblems. The tools are not completely integrated or interactive. VisualFoundation is sold separately by IES. To learnmore about IES VisualFoundation, click on this link to go to the VisualFoundation page on the IES website.

1. You can Export from VisualAnalysis using the Foundation Design feature.2. VisualFoundation can automatically create a VisualAnalysis project file (.vap) during analysis.

Foundation Design (Export from VisualAnalysis in to VisualFoundation)

Foundation Design allows you to export geometry and reactions from VisualAnalysis to set up a mat footing inVisualFoundation. You may quickly generate a footing geometry for one or more columns from the VisualAnalysisproject. The column locations are automatically imported and the reaction-forces from VisualAnalysis service load casesare brought into VisualFoundation as loads. Foundations created in VisualAnalysis (using the Create Foundation (forVisualFoundation) feature are kept “simple", omitting detailed FEA modeling of the mat foundation (just supportednodes). VisualFoundation provides foundation-specific checks and targeted design support from VisualFoundation.

How does “Foundation Design" (for VisualFoundation) work?

1. Select one or more supported nodes in your VisualAnalysis project (after an analysis is performed).2. Choose Structure | Create Foundation3. Run an analysis, analyzing all the Service Load Case to obtain reaction forces at nodes.

4. With the foundation selected, use Design | Foundation Design to launch VisualFoundation, which will create anew footing project.5. This VisualFoundation project can then be modified, and design checks can then be performed. You must SAVE thisproject to create a .vfp file that can be opened for future use.6. When you exit VisualFoundation, the “Foundation" in VisualAnalysis is updated with a new boundary and thickness.7. You can report a “Foundation Table" which lists all the footings by name, their thicknesses, area, and which columnsare supported. You might use this to help you coordinate with any saved VisualFoundation project files.

Go to Load Case Manager to enable analysis for all your service load cases (they may not be enabled by default). Onthe Service Case tab, select each service case that contains loads, and check the box titled "Include in analysis".





What are the Limitations of “Foundation Design" from VisualAnalysis?

Your support nodes must lie in a global plane (parallel to X, Y, or Z)Only member elements are exported as columns to VisualFoundation (walls or columns modeled out of plateelements do not export).The orientation of your model in VisualAnalysis is flexible, with Y-up the default. When the vertical axis isnot Z, then we map model coordinates according to the following right hand rule transforms, and load casesare renamed or "re-sourced" to line up.

Vertical Axis = X: Y-->X, Z-->Y, X-->ZVertical Axis = Y: X-->X, X-->Y, Y-->Z

You cannot create a multi-part footing or multi-thickness footing directly from within VisualAnalysisYou cannot "edit" or update the Foundation from VisualAnalysis. If you try to Design the foundation again itwill simply create a new project in VisualFoundation, each time you choose the command.You cannot open any VisualFoundation project you created (either from VA or not) and somehow “update"VisualAnalysis with changes you make. The design integration is strictly an export from VisualAnalysis toVisualFoundation.If you create a multi-part footing in VisualFoundation, only the “outside boundary" is shown in VisualAnalysis.The details of the foundation are not shown or reported in VisualAnalysis, just a “pretty picture" and athickness.You cannot choose when VisualAnalysis is updated from VisualFoundation, it happens when you exitVisualFoundation (and only if it was launched from within VA).

Using the .VAP Files Created by VisualFoundationYou can use the VisualAnalysis project file created by VisualFoundation to start a more sophisticated finite elementanalysis of your foundation using VisualAnalysis. You might use this project file look at horizontal forces on piles or toperform a dynamic analysis—neither of which is supported in VisualFoundation. VisualAnalysis also provides moreadvanced capabilities for designing grade beams, and foundation elements. The VisualFoundation project will also helpyou understand what VisualFoundation does for you behind the scenes in building the model to analyze. IES uses thisproject file to help validate VisualFoundation.

Detailed Operation

VisualFoundation can create a .vap when you run an analysis in VisualFoundation. The file is created with the samename and in the same folder as your VisualFoundation project file. Any existing .vap project file is replaced with a newone after each analysis—it represents the last state of your project at the time of analysis. If you modify yourVisualFoundation project after an analysis, those changes will not be reflected in the .vap file. Changes made to the.vap file cannot be exported back into VisualFoundation.

To learn more about IES VisualFoundation, visit the VisualFoundation page on the IES website.

8.3 IES VA-Revit LinkRequires: Advanced LevelThe IES VA-Revit Link free utility provides BIM (Building Information Modeling) features, through the ability to mergeor create .vap (VisualAnalysis) files from Autodesk Revit Structure. The link is bi-directional: the merge or createprocess can happen in either VisualAnalysis (.vap) or Revit (.rvt) files. VARevitLink runs as an add-in within RevitStructure, you do not need to have VisualAnalysis installed on the machine where you use this tool. Download this pagefrom the IES web site.

8.4 IES VAConnect




http://usa.autodesk.com/revit/structural-design-software/

https://www.iesweb.com/downloads/index.htm

Requires: IES VAConnectRequires: Advanced LevelVAConnect consists of two stand-alone utilities for connection design, currently just steel connections per AISC. Theseprograms can be launched from within VisualAnalysis. Integration with VAConnect can save a tremendous amount oftime because it exports forces from many load cases and multiple joints, saving you all the bookkeeping. In VAConnect,there is a steel base plate component with anchorage calculations, and a beam-to-column shear-tab component.

How to Use IES VAConnect

1. Turn on the Auto-Connections option in the Project settings. You may customize these.2. Define Result Type in project settings: VAConnect can use service case results or "pre-factored" results.3. Go to Load Case Manager and turn on the analysis for all necessary load cases (they may not be enabled for

service cases). 4. Use the Filter the Design View you show connection icons, click on the connection to view properties and

access VAConnect.

Connection Shapes & Geometry Limitations

General Requirements

Steel materials and shapes onlyGrouped connections must be 'identical' in type, shape, orientations, etc.Only LRFD load combinations are supported

Base Plate Requirements

Base plate is assumed to be perpendicular to the member's local axisA single member framing into a supported node or with spring-supports (no braces may frame into thisnode!)Permitted shapes: I-Beams, HSS (rectangular tubes), Pipe, Rectangle, or RoundWill not design plates for biaxial bending.

Shear Tab Requirements

Beam is nearly perpendicular to column or girder with end-released connection (~15° tolerance)A single member framing into a support column or girderPermitted beam shapes: I-Beams, ChannelsPermitted supporting member shapes: I-Beams, Channels, HSS, Pipe, Rectangle or Round

Notes:

The preferred approach is to export service-case results. While you may export “factored” results intoVAConnect, which would go in as “prefactored” loads. This is not the best way to design a connection. Usethe Export Results type in Project Settings.The coordinate systems are different between VisualAnalysis and VAConnect.Member local forces in VisualAnalysis are exported to VAConnect, transformed into the appropriate directions.Once the project is created in VAConnect it is not “updated” from VisualAnalysis, and no information transfersback to VisualAnalysis.If your forces change in VisualAnalysis you must start the process over or manually update the VAConnectproject.VAConnect reports are only available in VisualAnalysis 'per session'. If you exit and restart VisualAnalysis anyVAConnect reports are no longer present.No connection data input into VAConnect is currently stored or transferred back to VisualAnalysis.You may save VAConnect project files manually to store your input-data and settings for each connectiondesign.



https://www.iesweb.com/products/visualanalysis/vaconnect.htm

Troubleshooting

If you have problems launching VAConnect from within VisualAnalysis, check the following:

1. Uninstall any older versions of VAConnect (2.0 or 1.0) and VisualAnalysis (prior to 12.0), from Control Panel2. Check the "File Associations" on one of the example Base Plate and/or Shear Tab projects that ship with

VAConnect3. Re-install the latest versions of VisualAnalysis and then VAConnect

8.5 IES QuickFootingRequires: IES QuickFootingQuickFooting designs and checks a spread-footing under a column. The tool provides sophisticated checks of thefooting and pedestal including all the rebar details. Integration can save a tremendous amount of data-entry time byexporting reactions from many load cases and multiple columns automatically.

How to Use IES QuickFooting

1. Define Export Result Type in the Project Settings: QuickFooting can use service case results or "pre-factored" strength-level load combination results.

2. If exporting Service Cases, go to Load Case Manager and enable analysis for all the service cases. 3. After analysis completes, select one or more supported nodes in the Result View and choose Tools | Export

to QuickFooting.4. Design your footings and save your project through QuickFooting.

Notes

No information transfers back to VisualAnalysis. If your forces change in VisualAnalysis you must start theprocess over or manually update the QuickFooting project. Your QuickFooting project is completely independent of yourVisualAnalysis project.

When exporting strength-level results, for prefactored loading in QuickFooting, you get lower-quality design checks.Also, you may get extra load combinations from VisualAnalysis that do not need checking in QuickFooting.

Sign conventions and coordinate systems may be different in QuickFooting than in VisualAnalysis.

Purchase QuickFooting

To learn more about IES QuickFooting or to purchase licenses, please visit the web site or call the sales office.

Troubleshooting

Common solutions for export issues:

1. Uninstall older versions of QuickFooting from your machine, using the Windows Control Panel.2. Check the "File Associations" on a QuickFooting (.ftg) project file to make sure that Window Explorer will open

it with the latest version of QuickFooting.

8.6 CFS

Unity Checks in VisualAnalysis

Cold-Formed steel design checks are performed within VisualAnalysis by a component licensed from RSG Software. Youdo not need to purchase CFS to access this feature, you simply need the Design level. See Cold-Formed Design(Section 5.7) for more information about this feature.



https://www.iesweb.com/products/quickfooting

Creating Custom Shapes

The stand-alone CFS product may be purchased from RSG Software ( www.rsgsoftware.com) and usedindependently from VisualAnalysis. Using CFS you can create custom cold-formed shape libraries that can beincorporated into IES databases

Use File | Import | Cold Formed Library to add a custom .scl or .cfsl data files, or you may simply place your datafile into the Shapes (Section 1.9) folder for IES Customer data.

8.7 Windows Clipboard

Capabilities

The clipboard exchange is designed as a way to create, modify, or merge models and loads in ways that may not bepossible inside VisualAnalysis. It also allows data from other kinds of software. You can use the mathematicalcapabilities of a spreadsheet to manipulate your nodal coordinates for defining very complex, curving geometry.

Supported Model Objects: nodes, members, plates, and spring supports.Supported Loads Types: nodal loads, uniform and linearly varying member loads, uniform and linearlyvarying plate loads. Model objects may be Added or Modified (by Name)Loads may be added, modified or removed (set magnitude to zero)Factored Load Combinations may be addedCan export all items or only selected items. Also can export only certain types of items.Can be used to merge project geometry and connectivity information from one VisualAnalysis project intoanother.

Units

The current unit style is used for import or export, but you can override this by including a Units table at the top of yourfile with a unit style name. You may also include units along with any data value in any table. When exporting you canoptionally include the unit name on every data value.

Limitations

No support for areas, area loads, rigid links, or cable elements.Many modeling features, such as member taper, end zone, or centerline offsets are not supported.No support for thermal loads, nodal settlements, or other 'specialty' loads.Member wind & ice loads are exported simply as 'uniform' loads, so importing them back in will change theirdefinitions.Imported loads must be attached to imported nodes, members, or plates, or items that already exist in yourmodel.

Export

You choose what to export, based on type of object and selection status. You can export with units next to valueswhich will export with the current unit-style. If you choose to not export units, then we always export using ourinternal units of "Kips, Inches, Radians, Seconds".

Import

You are given the option to review the data found on the clipboard and confirm it is what you expected. No modelobjects have been added to your VisualAnalysis project at this point and you can end the operation by pressing Cancel.Objects existing in your model (by name) are modified, otherwise new objects are generated. You may delete loadson import by setting their magnitude to zero.




Import Data Format?

Discover the Import Format: create a simple model that contains the kinds of objects you want to import, andexport it. Then use that text as your template.

8.8 DXF FilesVisualAnalysis has the ability to import and export .dxf files which is a common CAD drawing format. This drawingformat typically contains basic geometry and connectivity information only, not an entire structural model.VisualAnalysis can do only so much with this format! DXF transfers will not support many of the features or propertiesof your models, but can help you save time in setting up complex models or in getting drawings started after creating amodel in VisualAnalysis.

Disclaimer

Because the DXF™ format is controlled by Autodesk® Inc., and not IES, Inc., it is not possible to read all DXF files, orto output files to specific format requirements, and these formats may change after our tools have been tested! Thetransfer features in VisualAnalysis have been tested with versions of DXF format up to AutoCAD® ASCII R14. CADsystems often use Z as the vertical direction, where VisualAnalysis prefers Y (though it functions with any axis vertical--set it in Project Settings), so you may wish to swap coordinates when importing or exporting.

DXF files are just "dumb" collections of drawing entities--they do not contain a finite element model!VisualAnalysis cannot always guess the intention of these entities and may require your assistance. Before importingyour DXF file, check to make sure that the lines connect nicely (don't overlap), that coordinates are reasonable andnear the global origin. For best results, split arcs and circles in to lines or poly-lines where they will cross members ornodes in your final model. You may need to import more than once, experimenting with settings or adjusting the CADdrawing slightly before it imports properly. Even then you may need to work with the project after importing to make agood model out of the data.

Import a DXF File

Use File | Import | DXF File to read a drawing into the current project. You can also use File | Open and selectDXF files to start a new project from a DXF file. This is a good way to create a model with complex geometry or to savework when a drawing is available before you begin. There are a number of options when importing from DXF files.

Layers: DXF files may contain lots of non-structural noise, be sure to include only the layers you want to import.

Select items to Import: This allows you to selectively import entities from the file while ignoring others. You can alsodefine basic default properties to items (like member shapes and materials) before importing.

Swap Y and Z coordinates: VisualAnalysis uses Y as the vertical axis by default, while most CAD programs use Z.You can perform this translation automatically. The default is to swap the coordinates.

Units: Select the units that were used in the DXF file.

Scale Factor: You can scale the dimensions of the DXF model up or down by a constant factor. Every nodal coordinateposition in the DXF file will be multiplied by the scale factor before it is displayed in VisualAnalysis.

Entities Imported:

POINTS become nodesLINES, POLYLINES, CIRCLES, or ARCS become membersSOLID or 3DFACE become a plate element

Export a DXF File



To save a model as a CAD drawing use File | Export to DXF. There are a number of options in the Export to DXFdialog box.

Swap Y and Z coordinates: VisualAnalysis uses Y as the vertical axis by default, while most CAD programs use Z.You can perform this translation automatically. The default is to swap the coordinates.

Units in DXF: Select the units to display information in the DXF file. For the maximum precision, you may want to usea "small" unit like inches or millimeters.

Scale factor: You can scale the dimensions of the model up or down by a constant factor. Every nodal coordinateposition in VisualAnalysis will be multiplied by the scale factor before it is written to the DXF file.

Selected items only: Selecting this option (on by default) lets you limit the items exported only to those items thatare currently selected.

8.9 STAAD Files

This feature is deprecated and may be removed. It is time to transition to the Windows Clipboard Exchange(Section 8.7), or other ways of generating models.

What is This Feature?

You may import or open STAAD (.std) script files as an entirely new project, also known as command language files. Toopen a STAAD file you may use File | Import | STAAD File. You may also export to a pseudo STAAD file, which willrequire editing before importing into VisualAnalysis or any other program.

Why STAAD?

The purpose of this feature is to make possible some data transfer of basic model and load information amongdifferent structural analysis products. It may not be easy.

STAAD has been around a very long time and many programs offer STAAD import/export abilities. This command is notdesigned to read most .std files without some simplification! It does not begin to support every feature of thiscommand language. You will need to modify your .std file in order for VisualAnalysis to read it successfully.

Limitations

Many STAAD commands are not supported either for import or export. Some commands are 'accessories' to the coremodel and load data and will just be ignored. Other commands will impede your ability to import the data at all. TheSTAAD file is text-based, you can edit it in Notepad to remove commands before importing!

We do not even expect to be able to read back a STAAD file that we write out! You may need to edit or modify anySTAAD file before it will import into VisualAnalysis.

Supported Commands

The following commands are acceptable, but may be significantly restricted in terms of options or features! Youmay still need to edit or remove some of them.

STAAD (SPACE)UNITJOINT COORDINATESMEMBER INCIDENCESELEMENT INCIDENCESMEMBER TRUSSMEMBER RELEASEMEMBER PROPERTY (Prismatic and database shapes should work, names must match exactly the VA shape pathand name)



ELEMENT PROPERTY (THICKNESS)DEFINE MATERIALISOTROPICSUPPORTSLOADINGSELFWEIGHTJOINT LOADMEMBER LOAD (UNI, CON, TRAP)ELEMENT LOAD PRESSURE (Local only)LOAD COMBINATIONFINISH

Unsupported Commands

These common unsupported commands may prevent your STAAD file from importing:

CONSTANT [use DEFINE MATERIAL and ISOTROPIC instead]PERFORM ANALYSISREPEATCODEGENERATEPAGEOUTPUT

8.10 Command Line

Batch Processing

VisualAnalysis supports a command-line analysis through an input file in the format used by the Clipboard Exchangefeature. The program will then perform an automatic static analysis and create an output report file. This type ofanalysis is useful for integrating VisualAnalysis with other software tools or systems or for managing a complex,changing model or other iteration processes.

Command Line

Example Command Line:

VisualAnalysis.exe "C:\data\myproject.txt" "C:\myresults.txt"

Command Line Specification:

[Path]VisualAnalysis.exe "input file" "output file" ["Report Style Name"]

Input File: Specifies the complete path to a text file in the format of Clipboard Exchange (Section 8.7). If the pathcontains space characters, it will need to be quoted.

Output File: Specifies the complete path to an output file, which may be .txt, .pdf, or .xlsx format. If the pathcontains space characters, it will need to be quoted.

[Optional] Report Style: Specifies a report style (Section 6.3) name, if omitted a default report will be generated.You must manually create or modify report styles using the interactive features of VisualAnalysis. Note that report stylesare saved per-machine (Section 1.9).

Operation

1. After parsing the input file, a static, linear analysis will be attempted automatically.2. If there is an error in parsing, it will be written into the output file.



3. If there is an error in analysis, it will be written into the output file.4. The program will exit with a return code.

Return Values:

0 = Success, presumably.

-1 = Failure, the error message will be included in the output report.

-2 = Failed to parse the command line.



9 How To

9.1 Design

9.1.1 The Design ProcessRequires: Design LevelThis topic is a 30,000 foot look at "how" you do design in VisualAnalysis. It assumes you familiar with the essentialdesign concepts (Section 5.1.2). The outline is the same whether you are designing with members or a plate mesh(concrete slab), the terminology changes from 'Group' to 'Mesh' for slab design.

Prerequisites: Setup Load Combinations (Section 9.1.2) and get "reasonable" Analysis Results (Section 4.2)!

Design Operations

Finding Design Features (Section 9.1.5): menus, windows, and more related to designModeling for Design (Section 9.1.3): Things to consider before constructing your modelLoading for Design (Section 9.1.2): How to set up loads for efficient design checksAnalyzing for Design (Section 9.1.4): Things to consider before you start designing

Design Procedure

1. Switch to Design View2. Adjust Design Parameters3. View Unity Checks4. Design the Groups5. Synchronize Design Changes6. Iterate As Necessary7. Create Design Reports

1. Switch to Design View

The first step in the actual design process is getting a Design View. This window looks much like a Model View, but hasa Filter, context menu, and design legend that will help you work with design groups.

2. Adjust Design Parameters

VisualAnalysis will normally automatically create design groups (Section 5.1.1) according to how the members areoriented in the model view, based on the setting in the Project Settings (Section 2.2) section in Project Manager. You may wish to take charge of this with manual groups. Once groups are defined to your liking you need to enterappropriate design parameters (Section 5.1.5) for each group (bracing, deflections, size constraints, etc.). Use theModify tab after selecting one or more members or groups.

If you set up design parameters when there are no analysis results, the unity checks will not recalculate with everychange. This can be far more efficient!

3. View Unity Checks

Unity check results are calculated and displayed automatically in the Design View if analysis results are available whenyou switch to this view type. Unity checks may have a prefix (~ = approximate), or a suffix (! = warning; !! = error)see the Help Pane or design report to understand warnings or errors.

Why is the Member Red or Failing?



In a Design View, double-click on a member or plate to see a design report. Alternately include a Design Member Results item into any other report.

4. Design the Group

To search for optimal member shapes or slab details, you may select any one or more elements in a group and chooseDesign the Group command. The software will search for a least-weight design and present you with some options. Available options may be limited by size constraints in the parameters. You may experiment with different shapeprofiles, or parametric sizes to really optimize the member for the demands.

Your design member shapes are approximate! That is, your analysis-model has not changed and the member forcesused were based on analysis using different member stiffnesses! Note that optimization is per-member, not per-model.As you change members, the demands on members may shift around your model due to relative stiffnesses. This maycause other previously designed members to fail again! VisualAnalysis does not currently offer a structure-wideoptimization.

5. Synchronize Design Changes Changes are not official until you use the Design | Synchronize Design Changes command. This is a 'feature' soyou can work through all of your design groups without losing the analysis results due to design changes.

To verify that your design selections really do satisfy all the requirements you will need to synchronize the changes orrerun the analysis.

6. Iterate As Necessary

Whenever you change the relative stiffness of elements in your model, you may also change the moment distribution.Thus, unity checks are made using forces calculated on a different model and are flagged as approximate. A tilde (~) infront of unity checks to indicates the checks are approximate, based on results from a previous version of the model.

After you synchronize and reanalyze the model, the design groups are rechecked. If all the members in the group arethe same shape, and all the members have unity checks less than one, then the group is considered as having a gooddesign.

7. Create Design Reports

The Find Tool window and Report View offer a number of ways to view the design check results. If you want toreally understand the unity-check value displayed, simply double-click on a member in the Design View.

9.1.2 Loading For DesignRequires: Design Level

Setting Up Load Combinations

The design software checks only the load combinations you define in Load Case Manager (Section 3.6), no othertypes of load cases are used by the design software. You may define any number of load combinations to check, usingautomatic building code combinations or your own custom load combinations. Each load combination is assigned to oneof the following design categories:

No Design: The load combination is ignored in all design checks.Allowable (ASD): Used for force or stress checks at service level.Strength (LRFD): Used for force or stress checks at ultimate strength level.Deflection: Used to check deflections. Note that deflection combinations fall into one of four IBC-definedcategories based on the types of loads they contain:

'L Only': A combination for just live loads



'L + D': A combination of dead and live loads, but nothing else.'W or S': Any combination including wind, snow or both types of loads (and any other types).'Other': Anything load combination that does not match one of the above.

Allowable & Deflection: Used for force checks and deflection checks.

Matching Load Combinations to Design Groups

The type of load combinations you use depends on the type of materials or design groups you are using. The followingtable shows how the type of group maps to load combination checks. When design groups are initially created the typeof load combination is chosen based on 'current' definitions in Load Case Manager. If you later change the materialspecification for design from ASD to LRFD you may also need to go back to Load Case Manager and add or changeappropriate load combinations.

Design Group Type Strength or Allowable Load Combination TypeAISC, CISC Steel Either, select the specification in the design parameters

NAS Cold-formed Steel Either, select the specification in the design parameters

ACI Concrete Strength (LRFD) only.

NDS Wood Either, select the specification in the design parameters

ADM Aluminum Either, select the specification in the design parameters

Connections (VAConnect) Strength (LRFD) only

Live Load Reduction

It is possible to check design groups for specific live load reduction levels. The process is two-fold. First use the loadcase manager to define the live load reduction levels that you wish to use. Note that additional load combinations aregenerated for each level, which has a significant performance impact. The second step is to specify that a design groupshould be checked for one of these live load reduction levels. That design group will then ignore the full live loadcombinations and load combinations for other reduction levels.

Checking Results Superposition

VisualAnalysis has the ability to run design checks on superposition result combinations. These are advanced featuresfor combining moving load or dynamic results with more traditional static analysis results. The superposition consists oftwo sets of results culled from many results instances or times: upper and lower extremes. We currently design-checkeach of these independently, and while this may provide more information to the design algorithms and catch situationsthat might control the design, it may very well miss certain combinations of forces that would control.

Results Checked?+Fx, +Mz, +My Yes

-Fx, +Mz, +My No

+Fx, -Mz, -My No

-Fx, -Mz, -My Yes

For example, we will check the maximum axial force (e.g. tension) in a member with the maximum moment. We willcheck the minimum axial force (e.g. compression) in a member with the minimum moment. But 'cross-over' checks arenot currently made, and depending on the shape, material used, bracing, magnitudes of forces, etc., othercombinations may actually control the design! So VisualAnalysis could be quite unconservative in this regard!

9.1.3 Modeling For Design




Members Elements vs. Combined Members

As you create models in VisualAnalysis, you should be aware of the design ramifications. In most cases, you will modela beam as a single member element. With girders, columns, and other types of frame elements, may choose to usemultiple member elements, for some reason. The normal approach would be to draw in the full-length of the memberand use the Connect Crossings feature to insure that the FEA model is split, but the member used for design checks isthe full length. This introduces a complexity in design, especially for bracing.

The design software looks primarily at your member, not the FEA (split) member elements. If you split members up atcrossing points, you may need to adjust the design options for span length, bracing, deflection limits, and otherparameters.

Pick Good Preliminary Sizes

Design is usually an iterative process. As you make design changes you change the stiffness and therefore the momentdistribution in your model, causing the design checks to become invalid. By selecting reasonable preliminary sizesbefore you run the design software you can save time.

Size Constraints

The design software allows you to limit the depth of beams, or the size of columns using Size Constraints. This canhave two benefits: The software will not 'design' members that fall outside of these boundaries (or will warn you if youmodel members outside these boundaries). This can also dramatically reduce the "design' performance when searchingfor a size that works, because many shapes in the database can be skipped! Note that setting beam width constraint isonly available in the 'Advanced' level of VisualAnalysis.

Design Tapered Members?

Although tapered members are supported in VisualAnalysis for analysis, there is no 'design' support for them. If youattempt to design a tapered member, you will get unpredictable results. At best, the member will be sized as aprismatic member; at worst, you will get garbage design results. For steel and wood members, you will now see anerror message in the Design View "tips" to indicate this condition.

Plate Design Limitations

The only support for plate element design is in the concrete wall/slab component.

If you are looking for design help with circular structures, or in materials other than concrete, you will not find it inVisualAnalysis—yet. For these types of problems, you will be able to get analysis results (stresses, deflections) andthen you may perform your design manually or with non-IES tools (such as a spreadsheet) using this information.

9.1.4 Analyze For DesignRequires: Design LevelThere are a number of considerations you should weigh carefully when deciding what to analyze and what options touse before you begin or complete your design.

Accuracy vs. Performance

Approximations

VisualAnalysis is an approximate, numerical tool for analysis. It uses the finite element method to calculatedisplacements and forces. The accuracy of the analysis is only as accurate as your model, and even then there aresome approximations and simplifications made. There is no concept of 'load path' in a finite element analysis.

For example, member internal forces are calculated at discrete points along the member. If the moment varies in anonlinear fashion and the number of calculation points is small, peak moments may be missed.



Control

VisualAnalysis lets you control the number of places along members where results are calculated. If you increase thesenumbers your results will be more precise whereas if you decrease them you will get better performance from thesoftware. VisualAnalysis by default will do a fairly good job of adjusting these values based on the size of your project.If you want to control it yourself, use Tools | Performance vs. Accuracy.

Performance Tip

If you have many load cases or many members, design checks can be relatively slow. You may wish to operate in apreliminary design mode for a while, using just a few key load combinations, or adjusting the performance settings(Section 2.2) to Fast until you have essentially completed your design. At that point you can change the load casesettings or adjust the performance settings in order to get the most accurate results and design.

Inspect Your Results Carefully

Before design checks are made, you should carefully check the analysis results you have received from VisualAnalysis.If you have large displacements or rotations, running the design software may yield equally erroneous results. Thesoftware is all based on "small deflection theory"; so large results are usually garbage results!

In some cases you will see reasonable displacements, but member stresses may be larger than yield stresses for thematerials. In other cases, buckling loads may have been exceeded, and for a first-order linear analysis they are notdetected or flagged during analysis. This condition will likely be "caught" by the design checks, but you might moreefficiently correct this problem in the model.

All member forces checked and reported in VisualAnalysis are with respect to the member element's local axes

It is recommended that you use the Tools | Result Check command before starting the design process.

Analyzing Non-Design Load Cases

Load combinations that are not marked for design checks are simply ignored by the design software. Look at LoadCase Manager on the Combinations tab for design settings. Service load cases are never checked for design.

In certain situations individual load cases will not analyze because they are unstable on their own. This will happen forexample if you have an 'overturning' load case which is unstable when analyzed separately from the self-weight of thestructure. By not analyzing load cases that are not required for design, you can improve the performance of thesoftware and reduce unnecessary report output.

Frame Instability Analysis

Some of the design modules, like LRFD steel, expect that you have performed a frame-instability or second order (P-Delta) analysis. The AISC Direct Analysis Method is also an option.

If you run only a first order analysis and the design software is expecting a second order analysis, you will need todefine an approximate moment-magnification "B" factor in the steel LRFD design modules.

Design for Dynamic Analysis

VisualAnalysis will check results from a Result Superposition case. Dynamic Response analysis, Dynamic Time Historyanalysis, moving load cases, and static load cases can be combined in a Result Superposition combination to produce"Envelope" results to be used for design. Because these are enveloped results, the Cb design parameter can not becalculated and is conservatively taken as 1. Also see notes here: Loading For Design (Section 9.1.2).

Another normal approach for doing seismic design is to come up with static seismic forces to apply in a Service LoadCase using some method acceptable to your building code. For example, use the Dynamic Response Spectra analysis,and then take the reported base shears from that analysis and distribute them back into the structure for a staticanalysis.



9.1.5 Working in Design ViewRequires: Design Level

Accessing Design Features

Most of the design commands are found in the Design tab of the main ribbon, which is visible only when the DesignView is active. For convenience, frequently accessed commands are also located in the Design View's context menu,accessed by clicking the right mouse button.

To see a list of your Design Groups and basic unity checks, you can use the Find Tool.

To find out why your members are failing design checks, double-click on the member and view the detaileddesign group results report.

Design View Window

VisualAnalysis provides the framework to glue the various design components together. The focal point for designactivity is the Design View. This window displays design information in much the same way as a Model View shows yourmodel and loads, or a Result View shows analysis results.

The Design View will show you the names of your design groups, unity check values, final design shapes, and additionalinformation regarding the status of the design process. The Project Manager Filter allows toggling the display of variousitems, including the Design Legend, unity checks, and span/deflection ratios. If you do not see the unity check valuesor colors displayed, you may change the Filter settings.

The Design View provides a context menu (right-click menu) for accessing design functions. There are also "Fly by" tipsavailable. If you hold your mouse over an element, you should see a note with more information about the unity checkfor that element, including critical warnings or errors.

Click on a member to select that member and the design group it belongs to. If you double-click on a member orplate in the Design View, you will get a Design Report for that item, assuming that one is available The Del key willdelete selected design groups.

Design Legend

The Design Legend explains the colors and line styles used to display the model in a Design View.

Not grouped. This element has not been associated with any design group, it is shown in blue.

Not checked. The element belongs to a group, but that group has no code checks or design results, it maybe that no analysis results are available. This element is shown in red and has a N.A. label.

Failed. The element is in red to indicate that unity checks failed. More information may be available in theFly by tip, or in a Design Report.

Grouped and checked. This element will be shown in color, where the color represents the unity checkvalue. If the member is shown as a dashed line, this is an indication that there was a warning or error duringthe unity check. More information may be available in the Fly by tip, or in a Design Report.

Design Commands

The Design tab in the main ribbon lists commands available for design groups and the design process.

Design View Context Menu

The context menu, or right-click menu, for a Design View provides a concise custom-tailored menu for the currentavailable options. You might consider this your first choice when searching for a relevant design command. The menu isdynamic, depending on what is selected, what is displayed, and what is in the model. All of the commands in this menuare also available in the main menu as well.



Copy Group Properties (Format Painter)

VisualAnalysis allows you to "copy & paste" design group properties.

1. Select a member, use Home | Copy2. Then select any other member elements before using Home | Format Painter.

You will be prompted to confirm you wish to copy the properties from one group to the other.

Design Result Reports

Design reports provide details of the design checks, including intermediate values, a summary of your designrequirements, actual load or deflection values checked, code or specification references for each controlling check, andan explanation of design errors or warnings. You can get a design report by double-clicking on an element in theDesign View, or through Add Tables in the Project Manager, while viewing a Report View.

Design offers a variety of ways to report the results of design checks. The Design View shows a graphical summary ofthe unity checks as colors and values on elements. You can get the complete design report for an element by double-clicking on the element in the Design View.

9.2 Selection and Editing

Selecting Items Graphically

Normal Selection

You can select items normally just by clicking on them with your mouse in a Model, Result or Design view. A singleclick selects the item and unselects everything else. The object to be selected will be indicated by a highlight color asthe mouse hovers over the object. A single click on the background will also unselect everything.

To select multiple items, hold the Ctrl key while clicking. (The Ctrl key lets you toggle the selection state of itemswithout unselecting anything.)

Select All of a Type

Use the Shift key to select all the visible objects of the type you click. Use Ctrl+Shift to select all the objects of thattype that also have the same name prefix. For example, Ctrl+Shift on a member named 'BmX001' would select all themembers whose names start with 'BmX'.

Selection Box

To select a group of items in an area, you can drag a Selection Box by holding the mouse (primary button) anddragging the mouse. Depending on the direction the Selection Box is drawn, two different selection behaviors result.

Left to Right: Objects entirely inside the selection box are selected.Right to Left: Objects entirely and partially inside the selection box are selected.

Keyboard Assist

When you have closely spaced objects, selection may be difficult. In these cases, holding down a keyboard “preferredkey” while clicking the mouse will chose the nearest of the specified type. The available keys are:

A – areas, area sides, or area side resultC – cables or cable resultsL – loads (member, node, area, area side, plate)



N – nodes or node resultsM – members or member resultsP – plates or plate resultsV – area vertices

Tab Selection

Another way to ease selection in tight areas is to use the Tab key while hovering over a point which may have severalobjects in the ray intersection list. As you press the tab key, objects will be selected in the order based on the distanceto each object with front object first. This can be very useful when viewing in the Picture View where sizes are trueobject size.

Element Search By Name

If you cannot see an object to select it, you can use the Home | Find (Ctrl+F) feature to locate a model element byname.

Find Tool Selection

Clicking on an element listed in the Find Tool (Section 1.3) window (for a Model View) will also select the element soyou can edit. Double-clicking in the Find Tool will zoom the graphics view to the region of that element, but keep inmind it may be filtered off.

Inspect or Edit Objects

Use the Modify tab in Project Manager to view the properties of one or more selected objects. If you have multipletypes of objects selected, you can use the type selector near the top to choose which type of object to inspect.

When editing multiple objects you may see some properties with the word "varies" to indicate that different objectshave different values. You can replace this with a valid setting to change all the objects.

Delete Objects

To delete objects, you first need to select them. This can be done graphically or with the Find tool. Use the Home |Delete command or its keyboard shortcut (the Del key by default).

The following hierarchy indicates typical cascading effects of deletion. Items nested further in are dependent upon theitems above at the higher level. For example, if you delete a node any elements connected to it are also deleted. If youdelete an element, any loads on that element (in all load cases) are also deleted.

NodesNodal LoadsMembers

Member LoadsPlates

Plate LoadsSprings

VerticesAreas

Area Loads

There are also implications for building code load combinations if you delete loads or service cases. In the design level,design groups will get removed or modified if you remove members or plates.

Undo & Redo

VisualAnalysis keeps an limited record of changes to your model and loads. You do not need to be afraid of making a



mistake. Use the Home | Undo command to trace back through these operations to undo the additions, deletions, ormodifications. An Home | Redo command is also available in case you undo too much.

Some operations are not undoable, notably editing design group parameters or deleting design groups. Please use morecaution with these items, until we get these into the undo system.

Be aware that certain operations will reset the undo, making it unavailable. Explicitly saving your project file andother complex or import operations will empty the undo and redo lists. Preference changes can have subtle effects onundo as well.

Use Unit Expressions

Most VisualAnalysis edit controls accept both a value and an optional associated physical unit. If you leave off the unit,the unit that was displayed previously is assumed. The unit displayed is controlled by the Home | Units command andthe type of value displayed. You may enter data using any of the built-in units. Here are the basic unitssupported in VisualAnalysis.

Quantity Type UnitsLength feet (ft), inches (in), millimeters (mm), centimeters (cm), meters (m), mixed feet, inches. (',")

Force pounds (lb), kips (K), Newtons (N), kilonewtons (kN), kilogram force (kgf), and tons (t)

Temperature degrees Fahrenheit (F), degrees Celsius (C)

Time seconds (s), 1/seconds (Hz)

Other physical quantities are based on these units and will use some practical combination. For example a moment maybe expressed in K-ft or K-in, but not in K-mm.

The display units are controlled by a unit-style, that you may select in the Home menu. You may customize thestyles, if none of the built-in ones work perfectly for your situation. You may change styles at any time.

Feet, Inches, and Fractions of an Inch

For length units you may also enter mixed feet, inches, and fractions if you use the tick or quotation markcharacters. VisualAnalysis will recognize the following expressions:

13 ' 5 3/16 ", as 13.4223 ft, or 161.1875 in2' 3 as 27 in3 1/2" as 3.5 in

Use Math Expressions

Just about every place where you enter a number in VisualAnalysis you may also enter a mathematical expression.These boxes will accept expressions including arithmetic operators. Type in expressions as you would any value. Useparentheses () to control order of evaluation. If the value is a physical quantity, place the unit last.

Math AvailableOperators +, -, *, /, ^, (, )

Constant PI

Exponential Functions LOG, EXP

Trigonometric Functions SIN, COS, TAN, ASIN, ACOS, ATAN

VisualAnalysis evaluates your expression and stores only the result. In Project Manager, expressions are evaluatedimmediately after you click away from the control. In a Dialog box, the expression may stay in the box until you dismissthe dialog.



9.3 Working in Model View

Drawing Mode

Set the drawing mode between {Draw Nothing, Draw Members, Draw Areas, Draw Plates, or Draw Cables} todetermine what kinds of elements you create by dragging the mouse. These options are available in the Structure tabof the main menu ribbon. You can use the Esc key to enter the Draw Nothing mode.

Drawing Tips: To prevent drawing elements in a Model View use Structure | Drawing Nothing (or the Esc key). Ifyou wish to draw elements between existing nodes but not between grid points, then turn-off any grids using Grids tabof the Project Manager.

Using Grids

Grids are helpful "layout" tools that let you predefine acceptable locations for nodes in the model. New in this version isthe ability to use multiple grids and grids with irregular spacing. The Grids tab of Project Manager allows you toaccess the Grid Manager for creating grids or deleting them.

With grids turned on, your mouse dragging operations will "snap" to grid-points as well as to already existing nodes (inthat order). You can adjust the grids at any time without affecting any existing model objects. Grids are only used tohelp define the locations of newly created nodes (or the elements defined between nodes and vertices). Show and hidegrids using the check boxes in Project Manager. You may turn on multiple grids at one time to draw in 3D.

Sketch a Member

In order to sketch a member in the workspace of Model View, make sure that you are in the "Draw Members" mode byselecting this item from the Structure tab in the ribbon menu.

Then drag your mouse and hold the button down while moving. You may drag to and from grid points or existingnodes. The mouse cursor will change to show that you are creating a member and will "rubber band" a line to showwhere it will go. Simply lift the mouse button to create the member.

If the grid is not turned on you will not be able to create any new nodes by sketching members. You may also sketchbeyond the border of the window, watching the coordinates in the lower right corner of the Status Bar to determinewhen to release the button, or you may wish to "zoom out" before drawing.

Members that you sketch default to the properties of the previously drawn or edited member, so it is helpful to defineproperties as you create your model.

Sketch a Plate

Make sure that you are in the "Draw Plates" mode by selecting this item from the Model menu.

To sketch a plate element in the Model View, Click once on a grid point or existing node to define the first corner. Thenas you move the mouse you will see a "rubber band" line and a special cursor. Click (push and release) on eachsubsequent corner of the plate to define the four corners. To draw a triangular plate element, click on the starting nodeto finish the shape. The operation might fail if the plate edges cross, or if the plate would otherwise be ill formed.

Sketching Area objects is similar to plates, except the polygon may have more than four sides.

Auto-Split Members

VisualAnalysis keeps your FEA model well-defined by connecting all elements at nodes as you sketch models. If yousketch a new element such that it crosses or intersects an existing element, VisualAnalysis will automatically split andconnect the new element (in a cascading fashion) to produce a well-defined finite element mesh. You can prevent anyauto-splitting behavior by selecting one of the crossing members and changing the Connect Crossings option. Then youwill need to manually split elements or otherwise insure your model is well defined.

There is a preference setting under Tools | Preferences, in the Desktop section that allows VisualAnalysis to promptyou for the desired action {split, no split, cancel} if you prefer a more explicit method of control.



Modeling X-Braces

The normal way of modeling X-bracing members is to draw two independent member elements that cross but do notconnect. This is appropriate because the members typically carry only axial forces and do not need to interact for avalid analysis. You can handle any design unbraced length issues in the design group by specifying a mid-point brace,as appropriate for your situation. To use members that cross but do not split, select one of the members and uncheckits Connect Crossings option.

Caution: If you decide to connect your X-braces (so you have four member elements instead of two), you not use thetension-only member option and be careful with member end releases. Both can easily result in unstable modelconfigurations.

Extend a Member

Generate new members along the axis of an existing member to either a specified length or to an intersection withanother member (if there is such a member). You may extend the member either forward (local +x direction) orbackward (-x). If you extend a member to a specific length and your new member crosses one or more existingmembers, you have the option of combining your new members with the member to be extended or leaving them asseparate pieces.

Note: If your extended members cross plate elements, these will be automatically split (meshed) regardless of yourauto-split settings.

Snap to Members

Drawing with a Grid

Members are drawn first to existing nodes, then to grid-points, and then finally to any snap-points visible on themember. You can set the number of snap points on members using the Model Filter.

Drawing without any Grids

If no grids are displayed, you can still sketch members between existing nodes or snap points.

Copy Member Properties (Format Painter)

VisualAnalysis allows you to "copy & paste" member properties.

1. Select a member, use Home | Copy2. Then select any other member elements before using Home | Format Painter.

You will be prompted with a small dialog box asking you which properties of the original member you would like copiedto the others, such as: Shape, Material, Beta Angle, or other properties. The tool also works in Design View to copydesign group properties.

Capture Graphics Image

You can create a bitmap image of the Model View, by using the Copy command. This puts an image on the Windowsclipboard that you can paste into VisualAnalysis reports or other Windows programs. This is true for all of the graphicviews: Model, Results, and Design.

The image will be the exact same size and image you see in the window. For the best quality image, make the windowas large as possible. Most word processors will scale images nicely to a smaller size for printing, but trying to make theimage bigger there will not improve the quality.

Printing Graphics

You may also use File | Print Preview to send the graphic view to the printer or PDF file. The image is scaled to fitthe paper, so landscape mode or changing the shape of the VisualAnalysis window by dragging the border may help



you fill the page. Page margins are also used as defined in File | Page Setup.

9.4 Creating Models

Use a Sketch Grid

VisualAnalysis allows you to draw your members and plates in the Model View. The most effective way to sketch modelsis to first define one or more Grids to work from. A grid lets you predefine the exact spacing and locations for nodes(joints or connections) in your model. To work with grids, Click on the Grid tab in Project Manager or use Home |Grid Manager menu command.

VisualAnalysis offers a number of different grid types that help you lay out floor plans at given elevations. Normally youwill create a number of grids and then enable (show) one or two of those at a time so that you can sketch elementsbetween grid points.

Sketch a 2D Model

The easiest way to create models is to sketch them in the Model View. Before you begin you should set up the SketchGrid and choose between drawing members or plates. Sometimes you might sketch without worrying about exactlocations of nodes so that later you can move nodes to correct the geometry. With the Grid turned off, you are onlyallowed to sketch members or plates between existing nodes in the model. Remember to fix out-of-plane supportswhen modeling in 2D.

Sketch a 3D Model

Sketch a 3D model in two phases. First sketch a wall elevation or a floor plan on a plane of the model. To do this,define a Cut Plane in the 3D space and turn on the Sketch Grid. Rotate the view to see this plane clearly and sketch asyou would for a 2D model. Repeat this process for multiple planes in the model, changing the plane center to adifferent value.

Once you have at least two planes of elements created, you can switch to full 3D sketching. Here you can remove theCut Plane setting to see the entire model and then rotate the view and sketch between any existing nodes. You couldalso create a Cut Plane in a perpendicular direction to draw members.

Import a DXF File

While sketching is very easy for most models, you might be more comfortable drawing in a CAD package. You mayimport geometry and connectivity information directly through a DXF file. This is especially useful for complexconfigurations involving angles, curved structures, or many offsets. The command is File | Import from DXF. Notethat you may also import a DXF file directly using File | Open, however this method does not offer any options on theimport and you will get default behavior! DXF File Details (Section 8.8).

Create Nodes

1. Use the Ctrl+D hot key for instant access to the New Node dialog box, for one at a time.2. Use the Project Manager Create tab, drag the Node item onto the Model View.3. Set up an Edit Grid using the Grids tab in Project Manager to define the locations for potential new nodes,

then you can just sketch members or plates between gridlines (the real reason you need nodes anyway!) Youcan readjust the grid or make new grids at any time to help you define where new nodes will go.

4. The New Member dialog (also in the Create tab of Project Manager) allows you to create multiple newmembers by specifying coordinates of the end points (new nodes are created if necessary). If you really enjoytyping nodal coordinates, this is sure a fun way to do it!

5. After you already have one node, use Structure | Generate Copies or Ctrl+B to generate copies of it ineither rectangular or polar fashion.

6. Manually type coordinates: Use the Create tab, Multiple Nodes item to enter coordinates for a long list ofnodes. You can also import the coordinates as text from the Copy/Paste Clipboard in Windows.



7. Want to Import a list of coordinates, and more? Use the Clipboard Exchange (Section 8.7) feature! Theeasiest way to use this tool is to export some nodes from an existing project, then Paste the results into Excel.Use this table as a "template" for future import operations.

8. Import a DXF file. (You must import the members or plates, you get the nodes for free!)9. Want to create a node at some distance off the end of an existing member? Use the Extend Member feature,

specify the distance, then you can delete the new member if it is not really needed.10. Need a node at the middle of a member or plate? Just use the Split Member or Split Plate command found in

the Context Menu (right-click). They offer multiple methods to locate the nodes.11. You can enable Snap points on members using the Model Filter. With, for example, 4 snap points on member

elements, you can draw new members to the middle or quarter point along any existing members.

Create Spring Supports

1. Select one or more nodes graphically, then Right-Click and choose Generate Spring Supports... from thecontext menu.

2. Select one or more nodes graphically, then Drag the Spring Supports item from the Create tab in ProjectManager onto the window.

3. Use the Structure | Soil Spring Generator, to generate springs for a group of selected plate elements.Details (Section 2.9).

Generate Typical Models

The standard version of VisualAnalysis allows you to quickly generate parametric models of common structures orstructural components. Use the Create Tab of the Project Manager to access this feature. The Generate Standard libraryincludes options such as typical trusses, building frames, walls, slabs, floor systems, tanks, and more. You may also addyour own parametric definitions for generating the types of models you create often. (See the chapter on Customizing.)

Generate Copies

You can copy any selected model objects using Structure | Generate Copies. The following list describes some ofthe many things you can do with the Copy and Paste approach to modeling:

Generate rectangular, circular, or linear patterns of model objects. For example, copy a floor plan of beams tothe next level.Generate a "mirror" image of a plane portion of the structure. (By rotating about the vertical axis.)Make a separate copy of your model, change it slightly and run a side-by-side comparison with the originalmodel.Copy member loads from one member to another within a single load case and scale them.Copy loads from one load case to another and scale them if necessary.

Create Multiple Models

It is often helpful to compare two models side-by-side. You may create two or more separate models in a single projectfile. This works well for static analysis to see how different configurations or conditions will affect the behavior of simplestructures.

Obviously, for large projects you will incur significant performance problems if you try to do this.

Import from Autodesk Revit Structure® via VA-Revit LinkRequires: Advanced Level

IES offers a free add-in utility for BIM integration with Autodesk Revit Structure called IES VA-Revit Link. This isa separate installation from VisualAnalysis. You may download and install VARevitLink from the downloads page.

9.5 Editing Models



http://usa.autodesk.com/revit/structural-design-software/

https://www.iesweb.com/downloads

Name Objects

Model objects are given default names when they are created. For example, members that are orientated horizontally inthe x-direction are labeled with the prefix BmX-and members that are orientated vertically are labeled with the prefixCOL-.

You should provide your own descriptive names to help you find, filter, and sort members of your model. Both theFilter tab in Project Manager and the Find Tool allow you to filter any visible or listed items by their name prefix.

To name a single object (node, member, plate, or spring), select it in the Model View and use the Modify tab of ProjectManager to type in a new name. To rename a group of objects use Structure | Rename. Although this may take alittle extra time initially, it can really save time later by making elements easier to view, edit, and report.

Rename Objects

The Structure | Rename command allows you to rename all objects or selected objects of a single type in one step.The command takes a name prefix, a starting number, and an increment number. You can also specify a directionalordering for the renaming process.

This command can fail if there are already objects with the new name. VisualAnalysis requires that objects of the sametype must have unique names.

Move the Model

This command actually changes the coordinates of your model, not just your view of the model! (Panning the view(Section 1.6) allows you to look at a different portion of the model in the window.)

To move the entire model or a selected portion of the model, use Structure | Move. This command will move nodes(and anything attached to them) specific distances in the global X, Y, or Z coordinate system.

Move Nodes

To move nodes and anything attached to them, select the nodes to move. Use the Modify tab in Project Manager andenter a move distance for the X, Y, or Z direction. At present, there is no support for moving nodes in polar or sphericalcoordinate directions. The Clipboard Exchange tool provides another powerful option for moving nodes in aspreadsheet.

Align Nodes

You may align a group of nodes to a common X, Y, or Z coordinate. Select the nodes and then enter a new coordinatevalue through the Modify tab in Project Manager. If you need to align nodes along an arbitrary line, you can do that bydrawing a member and splitting it into multiple pieces. Then delete the member elements if you do not need them.

Copy & Paste

You can select model objects (and loads) and use Home | Copy, and then Home | Paste to generate multiple copiesin either a rectangular or polar fashion. A Generate Copies wizard is presented when you choose the Paste commandto guide you through the process. Sometimes there is a simpler more direct paste approach in the Context Menu (right-click), especially when pasting loads from one element to another.

Rotate the Model

This command actually changes the coordinates of your model, not just rotating your view (Section 1.6) of themodel!

You may rotate all or selected portions of the model about any arbitrary point and any arbitrary axis of rotation. Selectthe portion of the model to rotate and use Structure | Rotate. You should note that member orientations are partiallydefined by the location of the member relative to the global Y-axis. As you rotate the model, you may also be rotatingmembers within the model as well as loads, end releases, and results that depend on the orientation of local



coordinates.

Split or Merge Members

You can model members (Section 2.4) as one continuous piece, such as a girder with infill beams connecting to it. Or you can split the girder into multiple pieces. Either way, we make sure your FEA model is connected and correct. Theimplications for you are reduced report sizes, easier result interpretation. There are also significant implicationsfor design checks (Section 5.2)--such as unbraced length.

Split Plates

Use this feature to break plate elements (Section 2.5) into smaller pieces. Plates are approximate elements. You willoften need to refine your model by using smaller plates. This is done by the plates of interest and using Structure |Split Plate. Newly created plates are given names based on the original plate.

Internal nodes are created automatically and you have the option to split members that lie along plate boundaries.Normally, you should split members to retain the continuous connection between the two types of elements.

Reverse Local Axes

Structure | Reverse Local Axes has the effect of changing the direction of the local coordinate system for theelement. This command can be applied to member and plate elements. Local coordinate directions will affect localloads, member end releases, possibly member orientation, and local results.

Move a Member in the Model

Two nodes define a member location. To move a member, while retaining its same connections to the model, simplymove the nodes. Select the node and use the Modify tab of Project Manager to change its coordinates. This will alsoaffect all other elements connected to the node.

To change where in the model a member is connected, you should change the member's start node or end node to bea different node. Select the member and use the Modify tab of Project Manager to change its nodes.

Change a Member's Length

The distance between its two nodes defines a member's length. To lengthen or shorten a member, simply move one ofthe end nodes. Select the node and use the Modify tab of Project Manager to change its coordinates. This will alsoaffect all other elements connected to the node.

Change a Plate's Size

Plate size is defined by the locations of the nodes, to change the size of a plate element, move one or more of thesenodes.

9.6 Working With Loads

Select the Active Load Case

Use the Command Bar to select which load case is displayed and active in a Model View, or which Result Case for aDesign View. A Model View shows one Service Load Case at a time. Result Views, Member Graphs and Plate Graphs willshow any result case, which may be results from a Service Load Case, an Equation Load Combination, Factored LoadCombination, Mode Shape, or Response Load Case. A single load case or combination may create multiple result cases(1st-Order, 2nd-Order, Envelope, Time Step, etc.)

Design Views do not show any one load case but rather results for all Strength and Serviceability load cases as definedon the Load Combinations tab of Load Case Manager.

Apply Loads



The easiest way to apply loads is to select the appropriate load case first, then select the items to be loaded (e.g., somemembers), then Right-Click in the Model View to find the Apply Member Loads command. Static, physical loads(Section 3.6) (forces, moments, etc) may be applied to Areas, Members, Plates and Nodes and Rigid Diaphragms.Other types of "loads" available include settlements (applied as nodal loads), seismic loads (applied as a designspectrum in a Dynamic Response load case or as a forcing function in a Dynamic Time History load case), or "inertialmass" (associated with a node directly).

Find Loads

Loads may be filtered in a Model View and selected individually or in groups just like other model objects. Sometimes itis difficult to locate loads visually. Use the Find Tool to view loads.

When using the Find tool with loads, you will need to use the load case selector that is in the Find tool rather than theone in the Status Bar.

The Find tool lists may be sorted on any column (Click the column title) and the columns may be resized (Drag thedivider between column titles). See the Essentials chapter for more information about the Find tool.

Select Loads

Select loads just like other model objects. Use the Filter tab in Project Manager to make them visible in the ModelView. Use the mouse to Click on the load to select it. Loads may be in different directions, so you may need to hunt forwhere to click in order to select it. If you turn off the nodes, members, and plates, it makes it easier sometimes.

See the Essentials chapter for more information about selecting.

Edit Loads

Loads are edited just like other model objects. Select a load, or multiple loads of the same type and use the Modify tabin Project Manager. To quickly edit a load individually simply double click it.

Delete Loads

Select loads in a Model View or Find tool and then delete them with Home | Delete or by pressing the Del key onyour keyboard.

Copy Loads to Another Load Case

Select the loads and choose Structure | Generate Copies to open the Generate Copies Wizard. Choose Copy toOther Load Cases and enter a scale factor if necessary, then press Next. Select the destination load case(s) in the listand press Finish.

You can also use this faster procedure to copy loads to another load case. Select the loads, then use Home | Copy.Now switch the active load case in the Status Bar and choose Home | Paste Load from Other Case.

During the copy operation you will have an opportunity to scale the load magnitudes in a linear (Ax + B) fashion.

Copy Loads to Other Objects

Select the loads and choose Home | Copy. Now select the destination objects in the Model View. Be careful to notchange the active load case. Finally, choose Home | Paste Special to open the Generate Copies Wizard. ChooseCopy to Other Nodes or Elements and enter a scale factor if necessary. Press Next and check the list of objects tomake sure the correct nodes or elements are selected and then press Finish.

In some cases, VisualAnalysis will recognize what you are doing after you have done the copy and selected otherobjects. In this case, a special menu item will appear similar to this: Home | Paste Load on Selected Members.When this command appears, you will not see the Generate Copies Wizard, the loads will simply be copied.

After the copy operation you can scale the load magnitudes in a linear (Ax + B) fashion, by selecting them and choosingthe Loading | Adjust Selected Loads command.



Factor the Loads

Building codes often require that you factor your loads. Normally these factors are applied through building codecombinations that are automatically generated by VisualAnalysis .

You may manually factor loads as you create them in a Service Load Case, but this is not very flexible. VisualAnalysisalso provides custom Equation and Factored Load Combinations to combine and factor loads. The Load menu providescommands to generate factored combinations.

Finally, after loads are created you can apply manual factors to them by selecting them and using the Loading |Adjust Selected Loads command.

Make Patterned Loads

VisualAnalysis provides limited support for creating patterned load combinations with live loads. Each service load casebased on live loads may include an optional pattern number 1, 2, 3, etc. When load combinations are generated withthe building-code load combination system, only cases with matching pattern numbers are combined together.

For any other kind of patterned loading situations you can create service cases manually to contain loads that areexcluded from the automatically generated building code combinations and then manually create custom loadcombinations to combine the loads in any way you choose.

See Factored Loads?

There is no graphical way to show the factored loads in an Equation or Factored Load Combination. Loads are onlyshown in a Model View for Service Load Cases. The primary reason for this is that the graphics would get very clutteredand most likely unreadable where many loads exist in the same locations in different load cases.

Find the Total Load in a Load Case

To find the sum total of loads in a load case you will need to analyze to get results. Look on the Result tab of ProjectManager, available when a Result View is active, to see the Static Check. The Static Check balances the total load ineach direction with the total reaction force in each direction.

9.7 Working in Report View

Create a Report

Use the Home | Create Report command, to get a new, empty reportClick the Report View tab, this will show you the last report you were viewing.Use the Report Selected... command from a graphic window's context menu.Double-click an item in a Result View or Design View to get a quick reportUse a style from the Reports tab in Project Manager, when a Report View is active.

If your reports get long enough, VisualAnalysis may stop trying to recreate the report automatically on everychange you make to tables, filters and settings. This allows you to rapidly get the report defined. When ready,click the Create Report button displayed near the top of the Report View.

Modify Report Filters

Use the Modify tab to change how the report is filtered.

Load Case Selection

You can define which load cases to include, all or those selected from a list, which will affect load tables.



Result Case Selection

You can define which result cases to include for analysis-result tables, again by all or those selected. The result-caseselection table can be sorted on different columns and allows for standard multiple-selection with the Ctrl key to togglea row, or click the first item and then Shift+Click the last item in a range.

Selected Item Reports

Similarly, model objects can be included or excluded by either selection or name filtering. If you choose the 'selection'method, you can toggle back and forth between the Report View and another graphic window to change the selectionstatus and the report will dynamically update.

Table Operations

To work with a specific table, click your mouse within the table. The Modify tab will display the table's options andavailable columns. Note that clicking on a table header will perform sorting. You can rename a table in the modify tab,which is useful if you include a table twice and display different columns in each instance of the table.

Changing Column Widths

To change the width of a column, simply use your mouse to Drag the dotted line separating columns.

Add or Remove Tables

To add tables to a report use the Add Tables tab. To remove or rearrange tables, use the Modify tab to drag themaround or click the X icon. (If you have a table selected, you can click in the white-space of the report to modify thereport properties rather than those for a single table.)

Sorting Tables

You can sort any table in a report by clicking on a column-header.

Extreme Rows Only

One important option on tables that show results, is the ability to compress the table to only rows that contain aminimum or maximum value. If you cannot find the information you need, you can uncheck this option to see all of thedata in the table.

Save a Report with your Project

Quick reports may be generated in a variety of ways. If you close your report, or create a new report this type of reportis "lost" (you may always re-create it the way you did originally). However if you edit a quick report or give it a name, itwill be automatically saved with your project file! When you re-open your project file you will be able to access it byname from the Command Bar, when the Report View is active. It is a good idea to give these reports a nice name thatwill make sense to you.

Please note: The report's data is not saved, just a template (organization, filters, and format) of the report! When yourecreate a project report the data is pulled "live" from your model, loads and analysis results. If you wish to save thedata from a particular model or analysis run permanently you should print it, or save the report as a separate file!

Save a Report as a New Style

Save a report that you have customized for use on other and future projects. This preserves the report contents andsettings in a data file on your machine, independent of any particular project file. See File Preferences (Section 1.7)for names and locations.

Save a Report to a File



You may wish to save a report permanently to archive the information it contains. Perhaps you want to use aspreadsheet to further process the numbers in a report. You may also need to edit it in a word processor or email thereport to someone. In all these situations, you will use File | Save Report As to create a file. Reports may be saved inRich Text File (.rtf), Plain text (.txt), Comma Delimited (.csv), or Tab Delimited format (.txt). The delimited formatswork best for going to spreadsheets.

In the advanced level of VisualAnalysis you can also save the report directly to Microsoft Excel (.xls) format, or workwith the Spreadsheet tab directly for basic spreadsheet manipulations of the data.

Export a Table to a Spreadsheet

Right-click within a report table and you can copy it to the clipboard to paste into another program.

Hint: If you routinely use this feature you might wish to customize reports so they import more easily into thespreadsheet. You may turn clear the box for "Use Table Lines" and the box for "No Table Duplicates". These options arefound under Tools | Preferences under the Report tab.

Delete a Saved Project Report

Reports that you customize will accumulate within your project so that you can get back to them easily, and they will beavailable to others who receive your project file. These report can be manually deleted: first create the report byselecting it from the Quick Report list in the command bar, then use the Modify tab in Project Manager, selecting theDelete Saved? option. The report will be thrown out as soon as another report is generated, or the project is closed.

Print a Report

Use File | Print to print the active Report View or File | Print Preview first to verify how it will appear.

If you need to make some changes before printing, use File | Page Setup, or Tools | Preferences on the Reporttab or Font tab.

Member Results at Offsets

There are two types of member result tables: the normal is very concise, showing just the range of forces, stresses, ordisplacements as one row for each element. The other type contains the word "Detailed" in the title, and allows you tosee member results at a specified number of offsets along the member's length.

Change Table Properties

To modify an individual table or summary, Click within the report section you wish to modify.

Modify Table Columns

Click within any report table, and it appears in the Selected Table tab of Project Manager. The included and availablecolumns appear in a checked-list. You can check or uncheck columns, and rearrange the included columns bydragging them up or down within the list.

Insert a Picture

You may paste any image from the Windows clipboard. This is a good way to get your current Result View included in areport. Use Home | Copy when the Result View is active, and then switch to the Report View, position the cursor, andchoose Home | Paste. Once the image is in the report, you may be able to resize it by selecting it and Dragging oneof the corners with your mouse. (Any graphic view may be copied to the clipboard through Home | Copy.

9.8 Working in Result ViewThe Result View is your primary access point for graphical and numerical analysis results. You will use this view to seeanalysis results graphically. It provides filters, legends, and images to help you find the information you need quickly. It



also works well as a starting point for generating printed reports of selected objects. A Result View shows the results ofone result case at a time. In the advanced level of VisualAnalysis, you will also have the ability to view envelope (orextreme) results.

Result Views can be used as interactive or printed reports themselves. Use File | Print Preview to see how a ResultView will look when printed.

Waiting For Results?

Analysis happens automatically on a background-thread when the CPU has 'spare time', whenever you make changes inyour model. Switch to a Result View to see the results, or view the status if the results are not read. Double-click onthe progress text at the bottom of the window (status bar) to get more detailed information about backgroundprocessing and progress. Most models will analyze in a few minutes or less, if you are waiting long times for analysis,consider the analysis performance (Section 4.4) options available.

Use the View Filter

Use the Result Filter tab of Project Manager to determine which results are displayed. You can toggle the displacedshape, on-frame diagrams, or show color contours. You can include extreme force (or displacement or stress) labels, aswell as object names and some properties. The filter will help you see only the information you need, while hiding thatwhich is not important. If you turn on the undisplaced shape, you will get a Model Filter to control how that is shown.

Showing Member or Plate Results

On the Result Filter tab of Project Manager, use the Results option under Members or Plates to change the typesof results to display. These include displacements, forces, and stresses.

Display On-Frame Graphs

Choosing Diagram from the Graphics drop down list under the Filter tab of Project Manager will display on-framemember graphs. By default the displaced shape is disabled when this option is chosen to clarify the diagrams. If youprefer to view the displaced shape and the member diagram you can always turn the displaced shape back on.

Use Result Legends

Legends are small windows that float in the Result View, when enabled. This is useful for interpreting the colors usedin plots and for finding the extreme values for all objects or selected objects when diagrams are shown. Members andplates each have a separate legend and they can be turned on or off independently. These legends may be dragged toany position within the window, and they are included if you print the window.

The legend may display one or more "Range Controls". These controls will allow you to filter the Result View to showonly results in a specified range of values. To restrict the range, Drag the top or bottom arrow with the mouse.

Create a Member or Node Graph

You can create a detailed moment, shear and deflection diagrams using the Member Graph command. You may selectone member or a chain of multiple member elements (that form a straight line) to graph. For moving load results, youcan also create influence line graphs for nodes or members.

Create Plate Graphs

Detailed diagrams for moment, shear and deflections are available for a plate mesh as well. To access these drag themouse on a line across the plate mesh where you would like to see the graphs.

Find Results

The Result tab of Project Manager is used to quickly get a feel for the Extreme Absolute, Maximum positive, orMinimum negative value of each result for the current result case. You will find a Statics Check for each direction,information about your model's self-weight and center of gravity, and summary information for dynamic results. The



Result tab is dynamic, based on the selection state in the active Result View, so you can use it to quickly getinformation about a specific element or node.

The Help Pane at the bottom of Project Manager shows result tips if you hold your mouse over an object (no need toselect it!).

The Find tool shows various result tables just like you would see in a report, these tables can be sorted on any columnby clicking the column header.

Animate Results

While viewing a Result View, you can right-click and choose the Animate Results command from the context menu.You can use this to see how the structure deflects, or how member forces change. If you animate a time history resultcase, we animate all the time steps available. To cancel the animation, right-click the mouse in the view. If youdisplay the window title, you can see the time step changing during the animation.

Printing

See Model View (Section 9.3) for tips on printing graphics.



10 Video Training

10.1 Basic Tutorial Videos

10.1.1 2D Truss Tutorial

How to Model a 2D TrussA quick tutorial on how to create a 2D truss model in VisualAnalysis. Learn how to sketch a model, set memberproperties, and define supports.

How to Load a 2D TrussIn this tutorial we look at loading features and how to use them to organize, apply, and combine loads for analysis. Thevideo touches on unit styles, the Filter tab, and member local coordinates. It also introduces Building-Codecombinations.

How to View Results and ReportsIn the final section of this tutorial we show how to control analysis, view results and work with reports.

10.1.2 2D Frame Comparison Tutorial

How to Model 2D Frames and Compare Different ModelsThis tutorial demonstrates how to create 2D models and work with them. We compare 4 different frames with differentlateral stability characteristics to show you can! We show how to apply loads, make a load combination and viewanalysis results.

10.1.3 2D Academic Truss Tutorial

How to Model an Academic TrussVisualAnalysis is set up for real-world modeling, where gravity exists and members do bend. There may be times whenyou want to create a "pure" truss. This short video shows additional steps you could to take to accomplish thissimplified model type. This is a supplement to the 2D Truss modeling tutorial.

10.1.4 3D Frame Tutorial

How to Model in 3D, The BasicsLearn basic techniques for creating 3D models, using editing grids. Also create a plate mesh for a wall with an opening.

10.2 Learn VisualAnalysis

10.3 Modeling Videos



10.4 Loading Videos

10.5 Result VIdeos

10.6 Reporting Videos

10.7 Design Videos

10.7.1 Concrete Slab Design VideoDesign of plate element groups or meshes is presented. Mesh design parameters are shown and reinforcing steelselection is included.

10.8 Integration Videos

10.8.1 VAConnect Videos''

10.9 Feature FridayIES produced a series of videos in 2017 under the banner "Feature Friday" to demonstrate various features inVisualAnalysis. You will find these, and future video training at our YouTube channel.

The play list link is: https://youtu.be/P1zjhM4Y3rY

Topics Include

Spreadsheet Import/Export (Section 8.7)Quick Tips for Modeling (Section 9.3)Custom Materials (Section 1.11)Design Member Optimizations (Section 5.2)Live Load Reductions (Section 9.1.2)Pattern Loads (Section 3.6)Virtual Joist Girders (Section 2.4)ASCE Load Helper (Section 3.9)Check-Levels for Design Groups (Section 5.1.1)Area Sub-Meshes (Section 2.7)Area MeshingConcrete Plate Design (Section 5.12)2nd Order Analysis (Section 4.5) with Tension-Only Members (Section 2.4)Parallel ProcessingMultiple Threads (Section 7.4) (Background Analysis)Auto Combined Members (Section 2.4)



https://youtu.be/P1zjhM4Y3rY

visualanalysis 17 user's guide · nodal load or apply member load command. 6. use the load...

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