strap - demo & tutorial models - atir. · pdf filestrap - demo & tutorial models 2.3...

© 2015 ATIR Engineering Software Ltd.

Version 2014

August 2014

Demo & Tutorial Models

STRAP - Demo & Tutorial ModelsI


Table of ContentsPart I Disclaimer 1

Part II General 2

................................................................................................................................... 31 Installing the Program

................................................................................................................................... 42 Defining the Demo models

................................................................................................................................... 53 Defining new models

................................................................................................................................... 64 Hints

Part III Demo examples 7

................................................................................................................................... 71 Plane frame - 1

................................................................................................................................... 132 Plane frame - 2

................................................................................................................................... 193 Plane grid - mesh

................................................................................................................................... 234 Plane grid - slab foundation

................................................................................................................................... 265 Plane grid - refined mesh

................................................................................................................................... 306 Space frame - 1

................................................................................................................................... 357 Space frame - 2

................................................................................................................................... 418 Space frame - walls

................................................................................................................................... 529 Space frame - dome shell

................................................................................................................................... 5810 Submodel

................................................................................................................................... 6211 Chess Loads

................................................................................................................................... 6412 Moving loads

................................................................................................................................... 6913 Results - elements

................................................................................................................................... 7114 Results - combinations

................................................................................................................................... 7415 Steel - hot rolled

................................................................................................................................... 7816 Steel - light gauge

................................................................................................................................... 8317 Steel - composite beam

................................................................................................................................... 8918 Concrete - beams & columns

................................................................................................................................... 9319 Concrete - slab detailing

................................................................................................................................... 10120 Dynamic analysis - Wall elements

................................................................................................................................... 10421 Bridge design - loads

................................................................................................................................... 10622 Bridge design - results

................................................................................................................................... 11123 POSTTEN - beams

................................................................................................................................... 11724 POSTTEN - slabs

Index 124

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STRAP - Demo & Tutorial Models

Disclaimer

The STRAP programs have been written by a team of highly qualified engineers and programmers andhave been extensively tested. Nevertheless, the authors of the software do not assume responsibility forthe validity of the results obtained from the programs or for the accuracy of this documentation.

The following examples demonstrate the program options used to definethe geometry and loads for structural models, to display their results and todesign the model elements. These examples are designed as teaching aids

only and should not be considered as a guide for accurate modeling anddesign of similar structures

The authors remind the user that the programs are to be used as a tool for structural analysis, and thatthe engineering judgment of the user is the final arbiter in the development of a suitable model and theinterpretation of the results.

The user must verify his own results

Windows is a registered trademark of Microsoft Corp.AutoCAD is a registered trademark of Autodesk Inc.Acrobat is a registered trademark of Adobe Systems Inc.

STRAP - Demo & Tutorial Models2


General

The DEMO includes:detailed instructions for defining the geometry and loads, viewing the results, designing steel &concrete elements and creating engineering drawings for the DEMO models.the files for several of the Demo models.these DEMO models may be revised but revisions to the geometry and loading will not be saved.

If you have installed the "STRAP 12 nodes version":This DEMO version is a limited version of the STRAP analysis and design program. New models with up to 12 nodes may be defined, solved and saved. For instructions, refer to Define a new model .One of the DEMO models is titled “Demo - Empty model” and it contains no existing geometry. Itmay be used to define any model up to the program capacity (unlimited - with submodels), but thegeometry cannot be saved.

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2.1 Installing the Program

Before starting the installation make sure that you have all the hardware required to run STRAP:A personal computer with Windows XP/Vista/Windows7At least 35 MB of free space on your hard disk

The files on the STRAP CD are in compressed format; they are copied to the hard disk by aninstallation program. The program cannot be installed by copying the files from the CD.

To install the program:Insert the CD in its drive.Follow the instructions supplied with the CD.Follow the instructions displayed on the screen:

Then select the program folder:

The program should be installed in a separate folder (the installation program creates a new folder if

necessary). To change the program folder, click Browse .

Click Install to begin the installation.



2.2 Defining the Demo models

To define one of the DEMO models.double click the STRAP icon in the Windows Program Manager screen; the program Main Menu andmodel list is displayed.

the DEMO models are found in the folder \STRAP1\DEMO. If this folder is not the one displayed,

click in the toolbar and select it.to select an existing model move the to the model name in the list and click the mouse to highlightthe line.follow the detailed instructions in each of the Demo examples.

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2.3 Defining new models

select (new model) in the toolbar.

Enter the model title:

arrange the preliminary geometry menu:

Then select one of the following methods for defining the new model:

Select a model from the STRAP library of standard structures. Define the geometry, loadsand load combinations. The model created by the wizard may be revised later using any ofthe STRAP geometry and load options.

Create the orthogonal grid lines as the basis for the new model. Nodes and elements are notdefined in this option.

The program displays a blank screen. Define the geometry and loads from scratch using anyof the STRAP geometry and loading definition options.

Note:if you have installed the "STRAP 12 nodes version" only models with up to 12 nodes may bedefined, saved and solved.



2.4 Hints

Help

STRAP provides the user with extensive on-line Help that may be displayed at any time. There are twoways to display Help while running the program:

press the key: Help for the current option will be displayed.click the Help option in the menu bar at the top of the screen and select Contents in the pull-downmenu: The Table of Contents of the Help for the entire program is then displayed on the left side ofthe Help window; select any topic in the list.

Toolbar

Note the row of small icons below the menu bar at the top of the screen. Clicking an icon providesaccess to many of the program options. Place the on an icon to display a ‘hint’ explaining its function.

Undo

If you made a mistake, simply click (Undo) in the toolbar; the program deletes the previousdefinition step.

Zoom

Click in the tool bar or select Zoom in the menu bar.

Try the Number of Windows option. This option creates a ‘split screen’ showing different views of themodel. Each view can be rotated to a different angle, have a different zoom and display differentinformation. Any of the windows may be the ‘active’ one; move the into a window and double clickthe mouse. When you define part of the geometry in the active window all of the other windows areupdated simultaneously.

Display

Click the Display option in the menu bar at the top of the screen to display various information aboutthe model - node, beam and property group numbers, support location and type, spring location, etc.

Verify node coordinates by selecting Define/revise dimension lines; the program displays thedistances between nodes that you select. The lines may be vertical, horizontal or parallel to any pair ofnodes.

Print graphics

Select the Output option on the menu bar and click on Print drawing. The current display is printed tothe scale and with the title that you define.

File management

The program provides complete file management capabilities (backup, restore, delete, etc.); select theFiles option in the menu bar in the program’s initial screen - .

Create your own model - Wizards

To create a new model of your own, click on the tab bar, and click in the toolbar. Refer toDefine a new model .

Try the Models wizard option - you only have to type in a few parameters to create standard structuralmodels. Note that the models available in the preprocessor are dependant on the Model type specified -click the Wizard button and the program displays the models that may be defined.

Remember that only models with 12 nodes or less can be saved in the Demo version.

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Demo examples

3.1 Plane frame - 1

Define the following plane frame using a Model wizard.

Demo 1 is a simple example that demonstrates the following:Definition of a simple plane frame, using STRAP’s model wizard library.STRAP contains a library of standard structures that enables the user to easily and quickly define themodel geometry and loads by entering a small number of parameters. The library can be extended toinclude additional model types.Utilization of STRAP’s “copy” feature for defining the diagonals in the upper stories.STRAP’s “copy” commands are powerful and sophisticated. The program refrains from duplicatingexisting beams. In our example, the program will duplicate only the diagonals and not the otherexisting members (beams and columns).

Define the model:

Main Menu

Click new model in the toolbar (or double-click Demo - Empty model in the model list if you haveinstalled the "STRAP 12 nodes version").

Preliminary Menu

Arrange the menu as follows:



Model wizard:

Click

Define the plane frame parameters:

type in the parameters as shown and click OK to continue

Define the section type for beams:

Click UB in the section type list and 406x140x39 in the section list.

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For columns, click and select UC and 356x368x129.

Define dead, live and wind loads and load factors for combinations.

The model wizard creates standard load cases from the basic load data. For the plane frame wizard,

nine cases are created - Press to display more details.

Note that loads defined by a wizard in the Demo version are not saved and cannot be displayed.Loads for this frame are also defined in Demo 4.

Define dead and live load:

Define Wind loads:

Define combination factors:



The program now creates the model according to the parameters and displays it on the screen withthe following Dialog Box at the bottom:

click Dimension to revise the dimension of the third bay to 7.5 m.

Move the to the horizontal dimension line so that the dimension of the third bay is highlighted withthe rectangular blip; click the mouse.

Press Esc (or right-click the mouse) to end the revision of dimensions.

Click the OK button to leave the Model Wizard. The program now enters the regular geometrymodule.

Geometry

click in the menu bar to display the node numbers

To define the bracing, click the icon in the bottom side menu

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Click the icon in the Beam options menu at the side of the screen

move the into the Dialog box at the bottom of the screen and set Prop.= 3; click .

move the adjacent to node 3 so that the node is highlighted with a ; click the mousemove the adjacent to node 9 so that the node is highlighted with a ; click the mouse

the program creates a beam linking nodes 3 and 9.

In a similar manner, create a beam linking nodes 4 and 8.

Copy the bracing to all floors:

Click the icon in the bottom side menu.

Click the icon in the Copy options menu at the side of the screen

move the adjacent to node 3 so that the node is highlighted with a ; click the mouse

Similarly select nodes 4, 8 and 9

after the node 9 has been selected, click the mouse again without moving the crosshair (or click in the Dialog box at the bottom of the screen).Select the reference node: move the adjacent to node 3 so that the node is highlighted with a ;click the mouse

Select the new location of the reference node:

select node 8.



click OK ; the program creates and draws the new bracing

Define the section properties of the bracing:

Click the icon.

Click the icon.

click the icon, select property type EQ.D.ANG and select 150x150x10

Click the Close button to complete the property definition.

You have now completed the definition of the geometry and the loads. To select another Demo model:click in the Tab bar (or File in the menu bar and STRAP model list in the menu).

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3.2 Plane frame - 2

Define the following plane frame:

Main Menu


Preliminary Menu

Geometry

Nodes:

Define the nodes with two "Line - equal" commands:

click the icon in the bottom side menu

click the icon

define the start node of the left column:



Define the end node of the left column:

Define the number of intervals:

Nodes 1 to 6 are created.

Repeat for the right column

Note: the nodes may also be defined with the option, where the base line consists ofone segment only.

Restraints:

select in the bottom Side menu.

select

select the two bottom nodes (1 and 7):

Repeat for Node 7, but double-click or click after highlighting the node.

Beams:

Define all beams with a single command.

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select

select

select Node 1 as the start of the grid baseline:

select Node 7 as the end of the base line and the top-right node (12) as the end of the height line.

The program draws a complete grid, including a beam between 1 and 7 ; to delete this beam -

select

select the beam to delete:

Properties:

select

Define the area and moment-of-inertia of the columns:



Define the column properties:

Similarly define property group 2 (beams) with values A=0.2 and I3=0.02.

Property 1 was automatically assigned to all of the members when they were defined. To assign thebeams to property 2:

click Assign

Select the “parallel” beam:

Property 2 is assigned to all of the horizontal beams.

click Close

Loads:

click in the tab bar.

select and define the vertical loads in Load Case 1:

define the load case title:

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select

select

select all of the horizontal beams as explained in Properties - assign.

select

select and define the horizontal loads in Load Case 2

define the load case title: "horizontal loads"

select

select



Select node 2 as explained in “Restraints”.

The load is displayed graphically on the node.

Repeat the process for the loads on nodes 3,4,5 and 6.

select

select

Results:

Select in the side menu

select combinations

Define the combinations as follows:

Graphic results:

click the icon

select the result type (moment, shear, etc) and the load case or combination; click OK . Thegraphic results are superimposed on the geometry.

Tabular results:

click the icon

click the icon

select the result type (moment, shear, etc) and the load case or combination; click OK .

You have now completed this Demo. To select another Demo model:click in the Tab bar (or File in the menu bar and STRAP model list in the menu).

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3.3 Plane grid - mesh

Define the grid of finite elements shown in Figure (a).

Demo 2 demonstrates STRAP’s powerful features of automatically generating a mesh of elements. Theuser can define an area of any shape (which may also include holes) and specify the preferred size ofthe elements. The program identifies existing supports (e.g. columns) and includes them in the meshnodes.

When defining a mesh area adjacent to an already defined mesh, the program will take care of asmooth connection between the elements of the two areas.

Main Menu


Preliminary Menu

set the default Units to meter and kN, the Display width range from -5 to 60 and the Display height range from -5 to 40 (if necessary).

set the Model type to Grid

click the button

Geometry

Nodes:

Define the grid of support nodes:


click the icon



The base line starts at coordinates (0,0); type 0 (the cursor automatically enters the X1= box) andpress [Enter]. The cursor moves to the X2= box; type 0 and press [Enter]. Press [Enter] or click the

button.

(Alternatively - move the on the screen so that the coordinates in the Dialog box are X1=0. andX2=0.; click the mouse.)

The base line ends at coordinates (50,0); type 50 and press [Enter]. The cursor moves to the X2=

box; type 0 and press [Enter]. Press [Enter] three times or click the button.

(Alternatively - move the on the screen so that the coordinate in the Dialog box at the bottom of thescreen are X1=50 and X2=0.; click the mouse)

Specify 5 segments and click OK .

Define the nodes on the grid height line as Equally spaced and click OK .

The height line ends at coordinates (50,32.5); type 50 and press [Enter]. The cursor moves to the

X2= box; type 32.5 and press [Enter]. Press [Enter] three times or click the button.

(Alternatively - move the on the screen so that the coordinates in the Dialog box at the bottom of thescreen are X1=50 and X2=32.5 (or dX1=0 and dX2=32.5); click the mouse.)

Specify 5 segments and click the OK button; the program creates a grid of nodes and displaysthem on the screen.

Note that nodes that are not attached to beams or elements are ignored by the program.

Supports:

Click the icon.

Click the icon in the Restraints option menu at the side of the screen.

the program creates the pinned supports ; click in the tool bar at the top of the screen to drawthem on the nodes.

Elements:

Define the mesh of elements:

click the icon

click the icon

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Define the contour line enclosing the floor area:move the adjacent to node A1 (Figure b) so that the node is highlighted with a ; click the mouse.Similarly select nodes A2 to A8 and A1 (again) to close the contour.

move the adjacent to node B1 so that the node is highlighted with a ; click the mouse. Similarlyselect nodes B2, B3, B4 and B1 (again) to close the contour of the opening.

Select End contour definition

Arrange the mesh parameters menu as follows:

The program superimposes the preliminary mesh (6.0 x 4.0) on the area defined by the contour.

Click the OK button.

The elements as displayed in Figure (b) are generated. Note that the existing elements in the contour



area are erased.

Click the OK button when the program asks Is the mesh OK?

Define the element thickness:

click the icon.

double-click the 1 - Undefined line (all elements were assigned to Property Group no.1 by default)

Set the Thickness = 25 (cm.)

click the OK button

Click the End button to complete the property definition.

You have now completed the definition of the geometry. To select another Demo model -click in the Tab bar (or File in the menu bar and STRAP model list in the pull-down menu).

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3.4 Plane grid - slab foundation

This raft foundation shows the use of elastic supports and the solution of a symmetric structure whereonly one-quarter of the structure is entered.

Main Menu


Preliminary Menu

Set the Model Type to Grid

Click the icon

Model wizard:

Click the Grid with elements button

Specify the parameters:

Define the slab properties:



click OK

Restraints:

select

select

click Select by window and create a window that encloses nodes 31 to 35

select

specify X2 rotation , click Select by window and create a window that encloses nodes 6, 12, 18,24, 30.

select

specify X1 rotation and X2 rotation, click Individual nodes and select node 36.

Beams:

select

select

Define beams 26-30 as a line:select Split at interm. nodeSelect node 1 as the start node of the line and node 6 as the end node of the line.

In a similar manner, select nodes 1 and 31 to define beams 31 to 35.

select

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click on Property 2, select , select and define the values:

click Close to continue.

Springs:

select

select

define the spring constant:

click Select all elements




3.5 Plane grid - refined mesh

Define the following gradually refined mesh:

In the STRAP main menu:


select Grid

select

select Grid with elements

create the 8x8 grid shown below with 1 x 1 elements with any thickness:

click OK twice to continue

select

select

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Define the contour by selecting nodes A, B, C,D and A again to close the contour.


The program superimposes the preliminary mesh (0.5 x 0.5) on the area defined by the contour:

the program generates the new elements:



click OK when the program asks: Is the mesh OK?

select

Define the contour by selecting nodes E, F, G, H and E again to close the contour.

Select End contour definition


The program superimposes the preliminary mesh (0.25 x 0.25) on the area defined by the contour:

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the program generates the new elements as shown in the Figure at the start of the example.




3.6 Space frame - 1

In Demo 3 we define a space structure:

In this Demo you will learn how to use STRAP’s more advanced features to quickly and easily definethis complex space frame.

Note: You are advised to run this DEMO after trying Plane frame - 1 .

The demo demonstrates the following features of STRAP:Definition of a single frame by using a Model Wizard.Duplication of the single frame to form the space model.Definition of the transverse truss as a ‘submodel’, also using a model wizard.The submodel feature enables to define part of the structure as a separate model and then add it tothe main model at specified locations. Similar to the Copy option, the program does not generatedouble members. Note that we will simply add the submodel to the main; we will not save it as aseparate entity (instance).Working in two windows (split screen). The whole model is displayed in one window. In the other one,the transverse truss is displayed and selected for duplication.The Mirror option for copying the transverse truss.

To define the model:

Main Menu


Preliminary Menu

Set the Model Type to Space frame

Click the icon

Models wizard:

Click the Frame truss button

Specify the parameters:

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click Skip all twice as we will not define section properties and loads in the Wizard.

The program displays the model, click OK to continue

Geometry

Copy the frame truss:

click in the toolbar to display the node numbers (it will be very convenient to switch the nodenumbers on/off many times during the course of building this model; these instructions will notmention it every time)

Click the icon in the bottom side menu.

Click the icon in the top side menu

Click the Select all nodes button

Select a reference node: move the adjacent to node 1 so that the node is highlighted with a ; clickthe mouse.

Define the new location of the reference node:

Click the by coordinates button

Press [F6] and type the coordinates X1=0, X2=0, X3=8 in the box at the bottom of the screen.

Click to continue



The program creates the new trusses. Click the button in the toolbar twice and the button once

to rotate the model to the isometric view (or use the Dynamic Rotate option).

Define the transverse truss (as a submodel):

Click the icon.

Click the icon

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Define one bay only (4 panels):

click Skip all (we will not define the properties)

the program displays the model, click OK to continue.

Copy the truss to create 3 bays:

Click the icon in the side menu

Click in the copy options menu


Select a reference node: move the adjacent to node 1 (lower left corner of the submodel) so thatthe node is highlighted a ; click the mouse.

Define the new location of the reference node: click the at an existing node button

move the adjacent to node 5 (lower-right corner of the submodel) so that the node is highlightedwith a ; click the mouse.

Set Number of copies = 2 and click the OK button; the program creates and draws the truss.

Click the full drawing icon in the toolbar at the top of the screen.

Add the submodel to the main model:

Click the icon in the side menu.



We select ‘Add + rotate’ because the horizontal axis of the truss is X2 in the submodel but it is parallelto X3 in the Main model.

Select reference nodes: move the adjacent to node 22 (at lower right end) so that the node ishighlighted with a ; click the mouse

Select nodes 1 and 6

Define the new location of the reference nodes in the Main model:

Select nodes 318 (the ridge of the bottom chord of the first frame), 18 (the ridge of the bottom chordof the last frame) and 32 (the ridge of the top chord of the last frame) or type the node numbers inthe Dialog box at the bottom of the screen.

Select node 316 as the second instance of the first reference node.

The program creates the four transverse trusses on the left, including the ridge.

Copy the transverse trusses to the right side:

Complete the definition of the secondary trusses by creating a mirror image of the entire model ! Notethat although we select the entire model, the program copies only the transverse trusses because itautomatically eliminates double members that are generated.

Click the icon.


Select a reference node: select node 301 (the bottom left node of the left leg)


Click the at an existing node button and select node 346 (the bottom right node of the right leg).

Click the OK button to copy the trusses

To select another Demo model -click in the Tab bar (or File in the menu bar and STRAP model list in the pull-down menu).

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3.7 Space frame - 2

Define the following steel and concrete spaces frame. This model uses the following options:cylindrical coordinate systemrotated local axesend releases

Main Menu


Preliminary Menu

Nodes:




select

Define a cylindrical coordinate system:

select

Move the crosshair to R = 3.5, Ang = 0, H = 0.0 and click the mouse (or press [F6] and typein the values).Move the crosshair to R = 3.5, Ang= 300, H = 0.0 and click the mouse.Specify 5 segments.

The six nodes on the base are created.

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Define the nodes on the grid side as Equally spaced

Move the crosshair to R = 3.5, Ang. = 300, H = 4.0 and click the mouse.

Specify 2 segments.

Nodes 7 to 18 are created (rotate the model to view all of the nodes).

select

Move the crosshair to R = 0.0, Ang. = 0, H = 6.0 and click the mouse (or press [F6] and type in thevalues).

Node 19 is created.

click to end the node definition

click to display the node numbers

Restraints:

select

select

specify Select by window

Create a window enclosing nodes 1 to 6 (even though nodes 2 and 3 are hidden they will be includedin the window). A pinned restraint is assigned to the selected nodes.

Beams:

select

Define the columns:

select

Define beams 1-2 as a line:select Split at interm. nodeSelect node 1 as the start node of the line and node 13 as the end node of the line; beams 1 and 2are created.

In a similar manner, define beams 3-4 (between nodes 2-14), 5-6 (between nodes 3-15), 7-8(between nodes 4-16), 9-10 (between nodes 5-17), 11-12 (between nodes 6-18).

Define the horizontal rings:

select

Define beams 13-17 as an arc:select Split at interm. node and Arc of beamsSelect node 7 as the start node of the arc, node 12 as the end node and any of nodes 8-12 as thethird node; beams 13-17 are created.

select

Define beam 18 between nodes 12 and 7.

In a similar manner, define the upper ring with beams 19-24.



Define the roof beams:

select

Define beam 25 between nodes 13 and 19.

In a similar manner, define beams 26-30.

Define the section orientation:

Rotate the local x2 axes of the columns so that they point towards the center of the circle:

select

Move the crosshair until the rectangular blip highlights node 19; click the mouse.

and select any of beams 1 to 12 as the 'parallel' beam.

Similarly rotate the local X2 axes of the top ring beams 19-24 so that they point towards the peak:

Define properties:

select

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select

Click IPE in the section type list and 240 in the section list.

Similarly, define Property group 2 as IPE 180 and Property group 3 as a 30x60 rectangular concretesection.

Select property group 2 IPE 180 from the list .

click Assign

Select ring beams 13-18.

Similarly assign property group 2 to the vertical columns.

Define Releases:

select



Select the lower ring beams 13 to 18.


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3.8 Space frame - walls

Define the geometry of the following 10-storey building that includes four walls extending the full heightof the structure:

Note:this example explains how to define the geometry; for dynamic analysis and interpretation of theresults, refer to Dynamic analysis - walls .the model is used for dynamic analysis only:the slabs thickness = 200 mm; rigid links provide in-plane rigidity.columns are not defined because their contribution to the lateral stiffness is negligible.

Main Menu


Preliminary Menu


click the button

Geometry

Nodes:

Define the wall reference nodes 1, 2, 3, 4 at ground level (X3=0.0):

click the icon

click the icon

Node 1: Move the crosshair to X1 = 0.0, X2 = 8.0, X3 = 0.0 and click the mouse or press [F6] andtype in the values:

Node 2: Move the crosshair to X1 = 24.0, X2 = 20.0, X3 = 0.0 and click the mouse.

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Node 3: Move the crosshair to X1 = 24.0, X2 = 0.0, X3 = 0.0 and click the mouse.Node 4: Move the crosshair to X1 = 9.15, X2 = 13.85, X3 = 0.0 and click the mouse.

Click

Supports:

Click the icon.

Click the icon.


Copy:

Copy the nodes to all 10 floors:

Click the icon

Click the icon


select any of the 4 nodes as the reference node


Define the floor levels at 3.0 m intervals (X3): Press the left mouse button and do not release; movethe into the X3 edit box (note that the coordinates will not change) and type 3.0:

set Number of copies: 10 and click OK .

click the Isometric View icon in the toolbar to display the entire model.

Walls:

Click the icon

Click the icon in the menu at the side of the screen

Select the section:

Define the properties and dimensions of Wall 1; the wall consists of one segment only and we will

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define the segment end at DX=0, DY=400:

Define Wall section no.2 :


Highlight section no . 2 and click Edit/add section

The wall is composed of two segments; the first ends at DX=4000; DY=0. Set the Thickness = 300,type in DX = 4000 and press [Enter]; the first segment is drawn in the center box:

the second segment is offset DX=0, DY=3000 from the end of the first segment. The cursor isalready in the DY= box; type 3000 and press [Enter]; the second segment is added to the display:

Note the “reference point” at the first corner denoted bythe . This is the point where the wall section will beattached to nodes in the structural model. Referring tothe floor plan at the beginning of this example, it isapparent that Walls 2a/2b will be attached at the cornerjoining the two segments in the section.

To move the reference point, click Reference corner ;move the to the new location so that it is highlightedwith the ; click the mouse. The will now appear at thecorrect location.

Click Close

Define Wall section no. 3:



Wall 3 is created by defining nine segments in the following order:

Note:segments 3 and 5 are coupling beamssegment 9 bisects segments 4 and 8 and dividesthem each into two new segments.


Highlight section no . 3 and click Edit/add section

Segment 1:

The segment is drawn in the center box:

Segment 2:

Specify DX = 1000mm and press[Enter]. The segment is drawn:

Segment 3 (coupling beam):

Segment 4:Specify Wall and DX = 2000

Segment 5:Specify Coupling beam and DX = 1000

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Segment 6:Specify Wall and DX = 1000

Segment 7:Specify Wall and DY = 2000

Segment 8:

This segment ends at the start of segment 1

move the to the start of Segment 1 so that it is highlighted with the ; click the mouse.

Segment 9:

This segment starts at the mid-point of segment 4 and ends at the mid-point of segment 8

move the adjacent to segment 4 so that it is highlighted withthe ; click the mouse.



Specify the location along segment 4:

Now define the end-point of the segment:

Move the adjacent to segment 8 so that it is highlighted with the ; click the mouse. Specify thelocation of the end point of segment 9 at the mid-point of section 8, as explained above for the startpoint.

Section 3 is now complete; Click Close.

Now we will attach the three wall sections to the model:

click the node number icon in the toolbar to add thenode numbers to the display:

click

select the wall section:

attach section 1 to line 1-41:move the adjacent to node 1 so that it is highlightedwith the ; click the mouse; move the adjacent to node41 so that it is highlighted with the ; click the mouse;

The program adds the wall section to the line 1-41.

attach section 2 to line 2-42:Specify Sect =2 and select nodes 2 and 42. Note thatthe orientation of the wall is not correct. We will rotate itafter the other three walls have been attached.

attach section 2 to line 3-43:Specify Sect =2 and select nodes 3 and 43

attach section 3 to line 4-44:Specify Sect =3 and select nodes 4 and 44

47



click the node number icon , the Display X1-X2

plane icon and the Restraints icon . Themodel is displayed on the X1-X2 without numberingor restraints:

All of the walls are oriented correctly except Wall2a(check the coordinates of the wall corners by

clicking on the Data icon)

Rotate Wall 2a:

click icon

the wall may be flipped or rotated:

Click Select by window

Create a window around Wall 2a; the program flips it into its correct position.

Floor slabs:

The floor slabs are modeled by dummy elements since the model will be solved only for dynamic loads. The elements are necessary in order to define the masses, but the size of the elements is notimportant.

We will define the slab at X3=3.00 and copy it to the other 10 levels.

click the Isometric View icon

Click on Remove in the menu bar at the top of the screen

Select Limit display to a plane

Select any three nodes at X3 = +3.00

Define the nodes at the X1=0 corners of the slab

click the icon

click the icon

Type in the coordinates X1 = 0.0, X2 = 0.0, X3 = 3.0 in the dialog box at the bottom of the screen

Type in the coordinates X1 = 0.0, X2 = 20.0, X3 = 3.0 in the dialog box



Click

Define the element mesh:

click the icon

click the icon

Select the four corner nodes and end the selection by clicking the first corner again.

Select the four corner nodes of Wall Section no. 3 and end the selection by clicking the first corneragain.

specify the grid parameters:

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and click OK when the program asks Is the mesh OK ?

click

select Property group 1:

click Assign

select the entire mesh:



select any two nodes in the mesh

click End when the model list is displayed again.

Click on Remove in the menu bar at the top of the screen

Select Limit display to a plane

click the Isometric View icon

Copy the slab to the other nine levels:

Click the icon in the main menu.

Click the icon in the copy options menu

Click the By levels button

Select level X3 as the height axis; select X3 = +3.00 and click OK .

Select a reference mode: move the adjacent to the node in the left corner so that the node ishighlighted with a ; click the mouse.



Click and hold the left mouse button and drag the cursor into the dialog box at the bottom of thescreen - the coordinate values in the box will not change as the cursor moves. Type the coordinatesX3=6.0.specify No. of copies = 9

Click OK to continue

Rigid links:

Define Rigid links in the slab plane:

Rotate the model so that it is displayed on the X1-X3 plane; select in the tool bar, click

X1-X3 plane and click End .


Click the icon in the Restraints options menu

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Select the nodes in the entire model, except the support nodes at X3=0.0 (use Select by window ).

You have now completed this Demo. To select another Demo model:click in the Tab bar (or File in the menu bar and STRAP model list in the menu).refer to Dynamic analysis - walls for the dynamic analysis of this model.101



3.9 Space frame - dome shell

Define the dome shell shown in the Figure below using either of two options:EquationsCopy and Rotate

Main Menu


Preliminary Menu


Click the icon

Option 1 : Equations


click the icon

Refer to the program Help for a detailed explanation of the sphere parameters U,V and R.

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Define the variable ranges:

U from 0 to 1 represents a half circle; therefore define U from 0 to 2:

V = 0 or 1 defines the full eight of a half-dome:

Define the location of the center of the sphere:

the program generates the nodes; to create the elements -

Two sets of nodes are generated along line 1-10 and 36 nodes are generated at the top of the dome.

To delete the superfluous nodes, select and Unify all nodes

Option 2 : Copy

This method makes extensive use of the Copy option using a cylindrical coordinate system..

To create the dome, define the wedge 1-10-12 (shaded in the Figure) and then copy it 35 times usingthe Copy – rotate option.



Define the arc 1-10:

X2 is the height axis of this arc (the axis perpendicular to the plane of thecylinder).

select

select

Define a cylindrical coordinate system:

click OK to rotate the model so that the X2 height axis is perpendicular to the screen.

select

press [F6] and type in the cylindrical coordinates:

define the line start(node 1) at:

R = 5.0 Ang =0.0 H = 0.0

define the line end (node10) at:

R = 5.0 Ang=90.0

H = 0.0

set the number of segment = 9 (10° each)

55



select

define node 11 at: R = 0.0 Ang =0.0 H = 0.0, i.e. at the system origin. This node is required forthe following Copy + rotate command.

click

Generate the arc 1-12 by copying and rotating arc 1-10.

select

select

define a cylindrical system as explained above, but with Global X3 as the system height axis

click OK to rotate the model so that the X3 height axis is perpendicular to the screen.

select

define node 12 at: R = 5.0 Ang =10.0 H = 0.0

click

to facilitate node selection, click Rotate in the menu bar and rotate the model to: X = -10 , Y = -10 , Z= 0.-

click in the toolbar to display the node numbers.

select

select

define a polygon enclosing arc 1-10.



select Create identical copies : Select 3 nodes

select the nodes and specify their new location using at an existing node :node 10 to node 12node 1 to node 1node 11 to node 11

specify the copy parameters:

The program now generates arc 1-12.

Define the elements in wedge 1-10-12:

select

select and define all of the quad elements.

select and define an element at nodes 1 - 2 - 13.

Generate the remaining wedges to complete the dome:

select

select

define a polygon enclosing the entire wedge.

select Create identical copies : Select 3 nodes

select the nodes and specify their new location using at an existing node :node 10 to node 12node 2 to node 13

57



node 1 to node 1

specify the copy parameters:

The program now generates the entire dome.

select to display the entire model.




3.10 Submodel

Define the following multi-story building using the submodel option.

the vertical elements - columns and walls - comprisethe "Main model" part of the structure.the beams and slabs are defined as a submodel; six"instances" of this submodel are attached to the Mainmodel.

Main Menu

Highlight Demo – Submodel in the model list.

Click in the tab bar.

The model contains the following elements:

click the icon in the toolbar to rotate the model to the X2-X3 plane (floor slab perpendicular to thescreen).

select

click New submodel

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click Select by window and create a box around the floor line (do not include the bottom nodes of thecolumns and walls).

Define the "Connections points" where the submodel is connected to the Main model. The programalready identified the nodes where the slab is connected to the columns and walls and created fixedconnection points, but we will change them to pinned.

select

select

Copy the vertical elements five times to create the upper floors

display the main model

and click the icon to display an isometric view

select

select

click Select all nodes ; the program will copy only the vertical elements because only those aredisplayed in "Main model".

select one of the base nodes as the reference point and the top of its column as the new referencepoint location:



set Number of copies = 5 and click OK

click in the toolbar to display the full model.

Create five more "instances" of the submodel:

select

add the submodels to the structure:

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Note that the floor slab is connected to the wall only at the "connection points" and not at all of the noesalong the segments. This can be rectified by defining rigid links connecting these nodes to theconnection points:

select

select




3.11 Chess Loads

In this Demo we will create the following load cases for the frame defined in Plane frame - 1 :

This Demo demonstrates STRAP’s unique “Chess load” option that automatically generates the criticalloading cases from basic Dead load and Live load cases (a & b in the drawings).

The program by itself identifies the continuous beams and applies the dead load and live load to theappropriate spans and with the correct load factors. The program is smart enough to identifyintermediate nodes if defined and ignore them when applying the load.

define the dead loads shown in Figure (a) in load case 1define all live loads shown in Figure (b) in load case 2use the program Chess loads option to automatically create load cases (c), (d) and (e).

Main Menu

highlight Demo - Chess loads in the model list

Click the tab.

Loads

Load case 1 - dead loads:

Click the icon.

enter the load case tile; type Dead loads and click the OK button

click in the bottom side menu.

Click in the top side menu.

Click the icon.

7

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Specify Select only beams parallel to a beam and click the Select all beams button

Select the “parallel” beam (the load will be applied only to beams parallel to this one); move the adjacent to any horizontal beam so that the beam is highlighted with a ; click the mouse.

Type in the uniform load =-21 (check that Direction: FX2) and click OK to continue.

The program creates the loads and draws them on the screen. Click the icon.

Load case 2 - live loads:

Click the icon.

enter the load case tile; type Live loads and click the OK button

proceed as described for Load case 1, except enter a uniform load = -13

to define the point loads, click

Click the icon.

Click the Individual beams button

Select one of the exterior roof beams; move the adjacent to any horizontal beam so that the beam ishighlighted with a ; click the mouse. Repeat for the other exterior roof beam.

Click the End selection button

Type in the point load =-24 (check that Direction: FX2 and that Fraction = 0.5) and click tocontinue

The program creates the loads and draws them on the screen. Click .

Chess loads:


The program correctly assumes that load case 1 contains all of the dead loads and that load case 2

contains all of the live loads. Correct the maximum/minimum load factors if necessary; click OK tocontinue.

The program displays the series of generated load cases; click to continue after eachcase.

Check the loads in the generated load cases:

Click the icon in the main menu and select the load case to be displayed, or

select Output in the top menu bar, then Display load commands and select the load case to bedisplayed.

You have now completed the definition of the loads. To select another Demo model -click in the Tab bar (or File in the menu bar and STRAP model list in the pull-down menu).



3.12 Moving loads

Use the Moving Load option to generate a series of load cases where the live load in each case is offsetby a constant increment relative to the previous case.

Note that the Moving Load option applies only to loads defined as Global Loads.

The Figure below shows an arbitrary element grid for which three load cases must be defined. In allthree cases the loads are identical, but the live load in each case is offset 2.0 m from the live loads inthe previous case.

Two types of Global Loads are defined:a pressure on a rectangular area defined by the user.a pressure on a rectangular area retrieved from the "Pattern' file.

Two methods for generating the loads will be illustrated:Option 1:Define the dead and live loads in load case 1. Generate the two additional load cases using themoving loads option. Note that the dead loads will be copied automatically to load cases 2 and 3.

Option 2:Define the dead loads in load case 1 and the live loads in load case 2.Generate the two additional load cases using the moving loads option. Note that the dead load willbe not be included in any of these three load cases.After solving the model, combine the dead load with each of the three live load cases using theGroup" option in the "Combination" module.

Main Menu


Preliminary Menu

Set the Model Type to Grid

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Click the icon

Models wizard:

Click the Grid with elements button

Define a 3m x 7m (minimum) plane grid of elements

Option 1

Loads:

click the tab

select

enter the load case title

select

select

define the load parameters:

select:

define the lower-left corner of the rectangle:

similarly, define corners at (2.0, 1.0), (2.0,2.5) and (1.0,2.5).move the cursor to the first corner (0.,0.) and click the mouse to close the rectangle; the program



displays the load:

Define the "Pattern" load:

select

define the load parameters:

select the pattern:

locate the pattern on the drawing:

repeat for the second wheel load.

select

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select

select the load case just defined

define the moving load parameters:

click End in the load case list.

To check that the cases were generated:

select ; the load case list displayed is:

Note that all three load cases contain the dead loads.

Option 2

Define the dead loads in load case 1.

Define the global loads in load case 2.

Generate the moving loads as load cases 3 and 4, as outlined above.

Solve the model.

select

select

select Add/revise a group

click on the first -UNDEFINED- line and enter the group name



select Generate a combination for each load in the group

click End


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3.13 Results - elements

For the plane grid defined in Plane grid - mesh , display graphic results for finite elements.

The graphic results for elements can be displayed in any one of three ways:Results at element centresdisplay the model geometry with the numerical value of the result written at the centre of each element.Contour mapdisplay the model geometry with a contour map of the results superimposed. Each line of the contourmap gives the location of a specified value of the result.Results along a linedisplay the results plotted along a section through the model.

For example:

Main Menu

highlight Demo - Results - elements in the model list

click in the tab bar at the top of the screen

Results

Results at element centres:

click the icon in the top side menu.

Specify:

click the OK button; the program displays the results as shown in Figure (a).

Click in the toolbar to zoom in on any part of the model (Figure (a) shows the lower-left corner).

Contour map:

19



Click the icon.

Specify:

and Fill contour regions with colour

click the OK button; the program displays the results as shown in Figure (b).

Results along a line:

Define the horizontal section line shown in Figure (c).

Click the icon.

Specify:

click the Define a section line button.

click the Parallel to X1 button

Move the to any point on the first interior horizontal line, i.e. so that X2=7 is displayed in the bottomdialog box. Click the mouse.

Define additional section lines or click the End button

click the OK button; the program draws moment diagrams along the sections as shown in Figure(c).


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3.14 Results - combinations

Display beam results for the plane frame defined in Plane frame - 1 and Chess loads .

The example will demonstrate the use of the Combinations options to create a series of combinations1.2D+1.2W+1.2L (BS8110), each combining the wind load case with one of the staggered load cases.

Please note the following:In STRAP you do not have to define the combinations along with the basic loading cases. You candefine them after the solution and revise them without solving the model again.STRAP also has an option to define a “group” of load cases. If a group is added to a combinationdefinition, the program will either:

automatically generate a different combination for each load in the group.add the sum of the load cases in the group to the combination.

Using this feature when applicable can reduce the work required to create large numbers of loadingcombinations.

Main Menu

Define the group:

highlight Demo - Results - combinations in the model list

click in the tab bar

Results

Combinations:

click in the bottom side menu

click in the top side menu

click the Add/revise a group button

Click the first -UNDEFINED- group in the list, type in a group name and click the OK button

click the Generate a combination for each load in the group button

click the End button

7 30



Define the combinations:

click in the pull-down menu

in the following menu: move the to column "9:wind" for combination no.1 (first row), click themouse and type 1.2. Press [Enter]; the crosshair moves into the adjacent column "group 1"; type1.2.

click anywhere else in the menu; the program creates the title "9*1.2+g1 *1.2" in the title column.

click the OK button. The program generates ‘n’ load combinations, where ‘n’ = the number ofstaggered load cases defined.

Tabular results:

click the icon

click the icon

Specify: Sort results by elements/nodes Beam results: End and max. in span

click the OK button; the program displays a table showing the moment, shear and axial force atboth beam ends as well as the maximum span result.

Click Exit in the menu bar of the table window to return to the main menu

Graphic results:

click the icon

Specify:

and Combination; select any combination from the pull-down list box

click the OK button; the program superimposes the result diagram on the model geometry.

Graphic results - Single beam:

Display all envelope results for the beams on the first floor:

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click the icon

move the adjacent to beam 5 (start of line) so that it is highlighted with a ; click the mouse.Similarly select beam 8 (end of line); the program draws envelope diagrams for all result types for theselected line of beam.




3.15 Steel - hot rolled

The model geometry as defined in STRAP does not provide sufficient information for the postprocessorto carry out an accurate design.

For example, Figure (b) shows a typical steel frame elevation. Figure (a) shows the same frame asanalyzed in STRAP. It is obvious that the postprocessor is unable to determine which STRAP membersform continuous beams (chains of members must be designed as a single unit by the Postprocessor),the location of intermediate supports for lateral-torsional buckling and axial buckling as well as designconstraints.

Define the following design data:

Sections Limit selection to:beams : UB shapescolumns : UC shapesbracing : double angles

Identical beams:Column 11-12-13 specified as an identical groupColumn 15-16-17-18

specified as an identical group

Column 19-20-22 specified as an identical groupBracing 23 and 24specified as an identical group

Intermediate supports:Members 4,7,8: "Continuous" support for +z major axis bending, major and minor axis buckling.

The support is provided by the floor slab.

Combined beams:Members 11,12: Beam 3 provides buckling support only for the major axis of this column, i.e. members

11 and 12 act as a single unit for minor axis buckling. Define major axis buckling and -zbending supports at the common node.

Main Menu

highlight Demo - Steel - hot rolled in the model list


Steel Design

select the British section table and click OK (the first time that the postprocessor is run on the

75



model).

Note the default parameters listed at the bottom of the screen. They automatically apply to allmembers in the model.

To change the default parameters, click the icon.

To define different parameters for a specific member, click the icon.

Section types:

The program can select the lightest section from a list (type or group) or check a specified section.


Specify Limit selection to section type and select UB; click the OK button

Click Select all beams

Select Draw in the menu bar and Section type/group/check in the pulldown menu; UB is displayedadjacent to every beam.


Specify Limit selection to section type and select UC; click the OK button

Set Select only beams parallel to a beam, click Select all beams and select any columnmember.

Click the icon and select EQ.D.ANG in the listbox; Click OK .

Click the Individual beams button

Select the two diagonal bracing members.

Identical:


Click the Define lines of identical beams button.

Specify One node in the window/polygon and

click the Select by window button.

Create a window about the lower end of all thecolumns. Note that each column forms a separate“identical” group.

Click the icon.

Click the Select a series of identical beams button

Click the Individual beams button and select the two diagonal members.

Supports:




Specify the following supports:

Click the Continuous support button.

Click the Individual beams button and select beams 4, 7, and 8.

Click the End button.

Combined beams:

Combine members 11 and 12 to form a single design unit and specify the major axis support providedby beam 3.


Select beams 11 and 12: click on beam 11, click on beam 12 and then click on beam 12 again toend the selection.

Compute:

click the icon and click the OK button; the program now selects the lightest sectionaccording to the user defined parameters. All load combination are checked for axial, bending,shear, LTB and combined stress capacity and for slenderness and deflection limitations.

The program displays a table showing for each member the section selected, the critical combination,the slenderness, deflection and the capacity ratios (actual/capacity) for each of the design checks.

click Exit in the menu bar.

Graphic results:

click Results in the menu bar.

click Display selected sections in the menu bar. The program superimposes the names of theselected sections on the model geometry.

77



click Results in the menu bar.

click Display capacity in the menu bar.

specify Colour by capacity and Display % of capacity

click the Result type box and select Axial force+moment from the list displayed (or any othertype).

click the OK button; the program superimposes the capacity percentage on the model geometry.Note the colour coding of the members and the text.




3.16 Steel - light gauge

This demo demonstrates the definition and design of a structure fabricated from Cold-formed (lightgauge) steel sections.

The program designs cold formed sections according to one of the following codes:AISI Specification for the Design of Cold-Formed Steel Structural Members:

2001 Edition of the AISI Standard “North American Specification for the Design of Cold-Formed SteelStructural Members” and Supplement 2004 to the 2001 Edition.CSA S136-1994Eurocode 3- Part 1.3 - 1996BS5950 - Part 5 - 1998 - "Code of practice for design of cold-formed thin gauge sections"

Note:the user may use the standard section tables included in the program or define his own sections.structures with both cold-formed and hot-rolled sections may be designed by the program.

The following design data is defined in the demo:

Sections:truss members : limit sections to C+Lipscolumns : limit sections to CDEE

Identical beams:members 23-24 specified as an identical group.members 7-8-9-10-11-12-21-22 specified as an identical group.members 1-2-3-4-5-6 specified as identical group.

Intermediate supports:Members 7-8-9-10-11-12:support for +Z major axis bending ,

minor axis buckling.Members 23-24: support for +Z major axis bending.

minor axis buckling.

Combined beams:Members 1-2-3; 4-5-6: Define major axis buckling at the common nodes.

Main Menu

Create cold formed sections:

Select Utilities in the menu bar.

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Select Create/Edit a steel section table.

Steel Table

Select File in the menu at the top of the screen.

Select Edit cold form table file.

Select Edit in the menu bar at the top of the screen.

Select Add section type in the pull down menu.

Click the button to open the section shape pull-down-menu

Select: 2C sections with lips front to front

Type the Section type name as - DCEE (notice that DCEE in the section type menu is highlighted).

Click the OK button

Select Edit in the menu bar and Select Add section to current type.

Click OK in the section data table

Click File in the menu bar

Click Exit in the file menu.

Main Menu

Highlight Demo - Light gauge in the model list.

Click in the menu bar at the top of the screen.

Steel design

Default parameters:

Note the current default parameters listed at the bottom of the screen. To change a parameter, click the

icon in the side menu.

specify the cold-formed design Code:



specify a new value for Fy:

Click OK

Sections:


Specify Limit section to section type and select C+Lips; click the OK button

Specify both nodes in the Window/polygon and click

Create a window about the truss.

Click the icon

Specify Limit section to section type and select DCEE ; Click OK

Click the Individual beams button and select the two column members.

To display and check the last definition:

Click Draw in the menu bar at the top of the screen

Click Section Type/Group/Check in the pull-down menu

(To Delete the section type from the display use the same option again)

Identical:


Click the Select a series of identical beams button

Click the Individual beams button and select the two columns (members 23,24)

81



Click the icon

Click the Define lines of identical beams button

Click the Individual beams button and select the beam members 21,22 and 1.

Note that each beam forms a separate identical group. (use the “Draw” option)

Supports:



Click the Intermediate supports button

Click the Individual beams button and select the beams 7-8-9-10-11-12.

Specify Distance from beam start = 4.5

Click the End button

Click the icon


Click the Intermediate supports button

Click the Individual beams button and select the columns 23, 24.


Click the Next support button





Click the End button

Use the “Draw” option to check the supports.



Combined beams:

Combine members 1-2-3 and 4-5-6 to form a single design unit:


Specify the following supports at the common nodes:

Select beams 1 and 3


Repeat for beams 4 - 6.

Use the “Draw” option to check.

Compute:


Click the OK button; the program now selects the lightest section according to the user definedparameters and slenderness and deflection limitations.

The program displays a table showing for each member the section selected, the critical combination, the slenderness, deflection and the capacity ratios (actual/capacity) for each of thedesign checks.

Click Exit in the table menu bar.

Results:

Select Results in the menu bar

Select Display detailed results in the pull-down menu.

Move the adjacent to column 23 so that the column is highlighted with a ; click the mouse.

Specify Design combination only and click the OK button

The program displays the detailed results for the column. Scroll through them.

click Exit in the menu bar.


83



3.17 Steel - composite beam

Design the following steel beam with profiled steel deck and concrete slab:

Parameters:The beam and slab are unpropped during construction.Bay width = 3.0 mEffective flange width = 2(L/8) =2.25 m < 3.00 mIPE steel grade = S355Studs connectors: design shear resistance Prd x Kt = 50 kN

Concrete: C25/30; fck =25 N/mm2, Ecm = 31000 N/mm2, density = 25 kN/m3

Loads:Construction stage:

Permanent:

slab self-weight = 2.58 kN/m2

deck self-weight= 0.08 kN/m2

beam self-weight - applied by programImposed: Construction load = 0.75 kN/m2

Composite stage:Permanent:

slab/deck/beam self-weight

Partitions, ceiling, etc = 1.25 kN/m2

Imposed: 2.50 kN/m2 , comprised of :

- short-term = 1.75 kN/m2

- long- term = 0.75 kN/m2

Load factors:Dead - γG = 1.35Imposed - γQ = 1.50

Main Menu


Preliminary Menu

select Plane frame

select

select Continuous beam

select Continuous beam; specify 1 span with L = 9.0 m



Click the icon (Select the European section table)

Click IPE in the section type list and 400 in the section list.

Skip the load definition

click OK twice and proceed to Geometry

select in the tab bar.

Loads:

Define 5 load cases:

Construction stage:1. load case

SW1:self-weight of beam (applied by program)Self-weight of deck and slab = (2.58+0.08)*3 = 7.98 kN/m

2. load case IL1: construction load = 0.75 * 3 = 2.25 kN/m

Composite stage:3. load case

SW2:Self-weight of partitions, ceilings, etc = 1.25*3 = 3.75 kN/m

4. load case IL2: long-term imposed load = 0.75 * 3 = 2.25 kN/m5. load case IL3: short-term imposed load = 1.75 *3 = 5.25 kN/m

Define the loads in load case SW1:

Click the icon.

Enter the load case title - SW1

select

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select

select

click Select all beams

define the load:

select

select and define the uniform load

click

Repeat for the remaining four load cases.

Click to solve the model.

Results:


select combinations

Define the combinations as follows:

click in the tab bar

Steel postprocessor:

select the European steel table and click OK



click

General tab:

Design code tab:Select Eurocode 3

Steel grade tabselect Fe510 (fy = 355)

Composite tab

Select Loads in the top Menu bar and Load types for composite sections in the menu. Loads on composite beam may be applied at two different stages:

to the non-composite steel beamto the composite steel and topping beam, either as a short-term load or as a long termload

Arrange the menu as follows, assigning each load case to a different stage:

87



click and click OK to continue.

The program displays the Results summary table; close it.

Select Results in the Menu bar and Display detailed results in the menu to verify the calculations:

89



3.18 Concrete - beams & columns

Design the beams and columns of the frame shown in Figure below and create a column schedule.

Beams and columns are designed separately; each has its own default parameters. The continuousbeams and columns must be defined by the user

Main Menu

highlight Demo - Concrete - beams & columns in the model list


Concrete design

Note:Note the Height axis = X2 parameter. The program assumes by default that all members parallel tothis axis are columns and that all members perpendicular to this axis are beams.beam default parameters are listed at the bottom of the screen. They automatically apply to all beamsin the model. Different parameters will be displayed if you select in the bottom sidemenu.

To change the default parameters, click

To define different parameters for a specific member, click .

Beams:

select in the side menu

Parameters:

click and the tab

Specify Shear reinforcement as: Links only

Diameter: Min=8 Max=12 Shear reduction

click the OK button

Define:

Define the continuous beams in the model. The program assumes that beams are perpendicular to the“Height axis” and can create them automatically.

Click the icon



click the Automatic definition of all beams button.

click the Display/revise beams button.

move the adjacent to any beam so that the beam is highlighted with a ; click the mouse. Theprogram displays the continuous beam schematically.

click the End button.

display more beams or click the End button.

Compute:

Click the icon

Specify For all defined beams and click the OK button. The program calculates moment andshear reinforcement for all of the beams and displays a summary table listing the results.

click Exit in the table menu bar

Results:

select Results in the menu bar at the top of the screen and select Display detailed results in the

pull-down menu (or click in the toolbar)

move the adjacent to any beam so that the beam is highlighted with a ; click the mouse.

Specify Display envelope only and click the OK button.

The program displays the detailed results for the beam. Scroll though them.


Columns:


Default parameters:

Click the icon

Specify

Click the tab

Specify the column lap and link details

click the OK button.

Define:

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Define the continuous columns in the model. The program assumes that columns are parallel to the “Height axis” and can create them automatically.

Click the icon

click the Automatic definition of all columns button.

click the Display/revise columns button.

move the adjacent to any column so that the column is highlighted with a ; click the mouse. Theprogram displays the continuous column schematically.

click the End button.

display more columns or click the End button.

Compute:

Click the icon

Specify For all defined columns and click the OK button. The program calculatesreinforcement for all of the columns and displays a summary table listing the results.


Results:

select Results in the menu bar at the top of the screen and select Display detailed results in the

pull-down menu (or click in the toolbar).

move the adjacent to any column so that the beam is highlighted with a ; click the mouse.

Specify Design combination only and click the OK button.

The program displays the detailed results for the column. Scroll though them.


Column table:

Click the icon

click the New table button.

type in the table name, select the table size and orientation.

Click Edit

click Select all beams to include all columns in the table

specify the table format parameters:



and -

click the OK button to display the table.

The table is displayed with diamond-shaped additional links. Let’s revise the links to rectangular ones.

Click the icon.

Click the icon.

Click the Link types button and select Use rectangular links where possible

click Select all beams to revise all the columns in the model

click the End button and click the icon

Highlight Table 1 and click Edit to display the revised schedule.


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3.19 Concrete - slab detailing

Design the reinforcement in a typical concrete floor slab:

Geometry:

Loads:

Dead: Beams and slab - self weightSlab - 4.0 kN/m2

Live: Slab - 1.5 kN/m2

Combinations:

1.35*Dead + 1.50 * Live1.00*Dead + 0.20 * Live

Main Menu

Highlight Demo - Concrete - slab detailing.

Click in the tab bar

Concrete design

Define the slab “spaces”:The slab can be divided into several subspaces by 'dividing lines'. Each dividing line represents aboundary for slab reinforcement:

different dividing lines may be defined for top and bottom reinforcementdifferent parameters may be defined for each spacereinforcement terminates at a dividing line (with optional overlap length)dividing lines may be defined along element boundaries or at beam locations

Select in the bottom side menu

The slab is divided into two subspaces for top and bottom reinforcement by specifying the start and end



nodes of the dividing line:


select Nodes 2 and 6 and click End

To verify, select Data display in the menu bar and then Space numbers - top reinf. and Spacenumbers - bot. reinf. in the menu; the space numbers are superimposed on the display.

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Specify the default type for the slab reinforcement. There are two main types:

Bars: the program details the diameter and spacing required in both directions in a series ofoverlapping rectangles that cover the slab surface

Meshes:

prefabricated fabric; the program calculates the number of bars required in either direction.

Select Bars for the both top and bottom reinforcement:

Click in the side menu

Click OK

The reinforcement is aligned by default parallel with the X1 and X2 axes. In the right space in ourmodel the bars should be placed parallel to the contour.

Click in the side menu.



Click OK

Select any two nodes parallel to the longdimension of the space to define the directionof the reinforcement and select any element

in the space using the Individual elements

option to identify the space.

Compute the required area:

Click in the side menu; theprogram displays a list of the requiredreinforcement area.

Draw the reinforcement:


Click New drawing and revise the drawing title in the drawing list.

Click Edit


click on any element in the slab (this option allows you to select a particular level in larger models).move the to the correct location on the drawing and click the mouse. The program draws thereinforcement drawing (zoomed portion shown here for clarity):

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Check that the reinforcement provided is adequate:

Click

Click

the program shows that the cover is adequate (refer to the color code in the menu):

Create the second drawing:


Click New drawing to create “Drawing no. 2"



Click Edit and follow instructions above, but select Bottom reinforcement

Bar schedule:


move the to the correct location on the drawing and click the mouse. The program draws the barschedule (zoomed portion shown here for clarity):

You may now revise any of the parameters and check the drawing; note that you do not have to erasethe drawing and add it again - the program calculates new detailing according to the parameter changeand automatically updates the drawing.

For example, revise the top reinforcement (Drawing no.1) to “Mesh” reinforcement.

Click the icon.


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click OK


Click and highlight the second row in the table - Drawing no. 2 - and click Edit ; the drawing is nowdisplayed with meshes instead of regular reinforcement:

Finally, display a summary of the reinforcement and parameters for each space and the for the model:

click Data tables in the menu bar and Display data table in the menu

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3.20 Dynamic analysis - Wall elements

This example is a continuation of Example 2.12. The files for this model contain the geometry asdefined as well as the following static loads applied to all floor slabs on all levels:

Dead = 8.0 kN/m2

Live = 1.5 kN/m2

The mass used for the dynamic analysis will be based on the dead load and 20% of the live load.

Main Menu

highlight Demo - Dynamic analysis - walls in the model list

click on in the tab bar.

Weights

click the icon

click the icon

click the icon



Click the icon

Select Seismic analysis in the menu bar and Method for combining modes in the pulldown menu

Select in the side menu.

click the icon.

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The results for all wall segments are displayed on the screen.

Add the dynamic results to the static results file:

Click the icon.

Display the results in STRAP:

Select in the tab bar.

click the icon.

The moments in the walls are displayed.




3.21 Bridge design - loads

The bridge module automatically calculates the critical loading pattern that generates the max/minresults for any result type at any point on the bridge.

General

Divide the bridge into lanes and then divide each lane into strips perpendicular to the axis of the lane.Solve the model: the program automatically applies a unit load to each strip in a separate load case(no. of load cases = no. of strips). The program uses the results of those cases to calculate worstcase effects by means of superposition.Define lane loads: specify the vehicle loads and the distributed loads required by the codes on eachof the lanes.Create load cases: tell the program how to arrange the various lane loads to create the design loadcases.Transfer results to STRAP: append a load case to the STRAP results files that contains an envelopeof the maximum results for vehicle load.Create combinations of the vehicle results and the self-weight and temperature loads.

Main Menu

Highlight Demo – Bridge design - loads in the model list.


Bridge

Lanes:

The bridge consists of 2 parallel lanes, each 9 feet wide. They are defined by specifying the center lineaxis and width.

select

select

Click Node 5 to specify the start of lane.

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Click Node 8 to specify the end of lane.

Define the lane parameters:

Similarly define lane 2 between nodes 13 and 16.

Load distribution:

The generated loads may be applied to nodes, elements or selected beams.

Select Options in the menu bar.

Select Load direction to specify the Global direction of applied loads.

Select Options in the menu bar.

Select Loads distribution in the pull down menu.

Solve the model:

STRAP creates one case for each strip in the model (a unit load is applied to the strip), i.e. 240 loadcases are solved in this model.

You have now completed this phase of the design. To continue:12-node Demo version:The large number of load cases exceeds the limit of the Demo version. To continue, please continueto Bridge design - results which is identical to this model but includes the result files. Regular and 30-day versions:Select File in the menu bar and Solve in the pulldown menu and then continue according to theinstructions in Bridge design - results .

To run a another demo:click in the Tab bar (or File in the menu bar and STRAP model list in the menu).

106

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3.22 Bridge design - results

Main Menu

Highlight Demo – Bridge design – results.


Bridge

Display influence lines:

Display influence lines for any STRAP beam ,element or node for any result type. For example, displaythe influence line for M2 moment at the center of beam 111.

Select Results in the menu bar:

To select beam 111, highlight it with the and click the left button of the mouse.

The program displays the following influence line:

Define lane loads:

Specify the vehicle loads applied to the lanes. The following lane loads may be defined: uniform,vehicle, knife-edge loads.

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select

select

Define load cases:

Assign a lane load to each lane to define a load case. The program applies the load to each of thestrips along the length of the lanes; only those loads that contribute to the requested maximum/minimumresult are used.

Define three load cases:1 - apply lane load A to lane 1 only.2 - apply lane load A to lane 2 only.3 - apply lane load A to both lane 1 and lane 2.

Define load case 1 and 2:

Create the load cases by specifying all possible permutations of the lane loads on the selected lanes.The program creates load cases by interchanging the lane loads.

select

select

Define load case no. 3.



select

Display selected resultsThe program displays the loads applied to the various strips that are required to generate themaximum/minimum result. For example, display the maximum absolute value for Mx result in thecenter of element 58.

Select Results in the menu bar.

To select element 58 click the mouse.

The program displays the location of the loads applied to achieve the max results.

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Transfer results to STRAP

Create a single STRAP load case consisting of a maximum result envelope for all results types(moment, shear, etc.). Note that you can create separate load cases for each result type.

The program will search for the critical load pattern for each result type for each node, element and

beam (1/10th of span). The results will be transferred to the STRAP results file.

Select Results in the menu bar.

select Update STRAP result file.

The program runs about one million comparisons for each beam in this model for computing theenvelope and takes a few minutes to complete the calculation.

Results:

Select in the tab bar.

Combinations

The model also contains other load types e.g. self-weight and temperature (already defined). Let'snow define factored loading combinations of these loads with the vehicle loads envelope.





select

click the icon


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3.23 POSTTEN - beams

Design the following post-tensioned bridge:

where:The structure is defined as a space model; note that the program calculates cable losses according tothe curvature in both directionsThe bridge deck section is created in the STRAP section generator program (CROSEC). Thesection is found in file DEMO13.SECLive loads are generated by the STRAP Bridge design module based on standard vehicle loadsarranged on two lanes.

The model files as installed include the complete geometry, regular static loads, bridge loads andcombinations:

Geometry:

Loads:

Three load cases are defined:1 = Dead load2 = Asphalt3 = Temperature

Bridge:

Load cases transferred to STRAP:Maximum M2 envelopeMinimum M2 envelopeMaximum V3 envelopeMinimum V3 envelopeMaximum axial force envelope



Minimum axial force envelope

Results:Group “GR1" : ‘Includes’ all six Bridge load cases (Generate a combination for each load in the group).Combinations: 1 = 1*1.00

2 = 1*1.203 = 1*1.00 + 2*1.00 + + 1.2*GR14 = 1*1.20 + 2*1.20 + + 1.5*GR15 = 1*1.00 + 2*1.00 + 0.8*3 + 1.0*GR16 = 1*1.00 + 2*1.00 - 0.8*3 + 1.0*GR17 = 1*1.20 + 2*1.20 + 1.0*3 + 1.25*GR18 = 1*1.20 + 2*1.20 - 1.0*3 + 1.25*GR1

Main Menu

Highlight Demo – POSTTEN - beams.


POSTTEN

Define the beam:


Select Beam 1 as the start beamof the post-tensioned beam andBeam 53 as the end beam:

Parameters:

Define the default parameters for all beams in the model, including parameters for cables,reinforcement, losses, time steps, etc. Note that different loss parameters may be assigned tospecific beams using the Design - losses option.


Set the parameters in the following menus by clicking on the tabs:

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Click OK to continue

Stages:

Create a "stage table" when all cables are not prestressed at the same time or all loads are not appliedat the same time. Each stage is defined by the number of days from the start of construction.

Click the icon and arrange the menu as follows:





Design:

Define cables and their trajectory in the beam.


select the beam


The program displays the ‘Magnel diagram’ at three locations along the span; these diagrams showthe possible combinations of prestress force and cable eccentricity that generate acceptable stressesthroughout the beam at all stages. The diagrams below are based on an estimated loss since thecables have not yet been defined and do not include the effect of secondary moments because themodel has not yet been solved for the added prestressing loads.

The program displays upper and lower boundaries of eccentricity in which the centre-of-gravity of thecables must lie. Note that the boundaries are calculated based on the estimated losses.

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To define the cable trajectories:


Double-click cable 1

First define the five parabolic segments shown in the drawing:


Move the to the three points defining the parabola as shown above; repeat for the other parabolas


Select two adjacent parabolas; the program connects them with a new segment and smooths thecurve.

Repeat until one single cable is formed.

click the icon

Click

The program has still not added the effects of the prestressing to the model (secondary moments)orcalculated the exact losses:

Click the icon in the side menu.Solve the model for the cable force loads, including losses, at each of the stages; secondary momentsare calculated (new STRAP load cases are generated).


select the beam

The program recalculates the upper and lower eccentricity boundaries. The cable path may not liewithin the boundary. To correct the trajectory:





Click the icon in the side menu and use any of the options to move a segment.


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3.24 POSTTEN - slabs

Design the following post-tensioned flat slab:

Load cases:

1. Dead load: 0.3 t/m2 + self-weight

2. Live load : 0.4 t/m2

Combinations:

Moment Reduction:

600x600 mm rectangles have been defined around all of the slab support columns

Main Menu

Highlight Demo – POSTTEN - Slabs.


POSTTEN

Select in the bottom side menu.

Define the slab area:




select Nodes 80 and 297 to define the base line.

offset the top boundary 4.4 meters from the base line.

Parameters:

Define the default parameters for all beams and slabs in the model, including parameters for cables,reinforcement, losses, time steps, etc. Note that different loss parameters may be assigned to specificbeams/slabs using the Design - losses option.


Set the parameters in the following menus:

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click OK to continue

StagesCreate a "stage table" when all cables are not prestressed at the same time or all loads are not appliedat the same time. Each stage is defined by the number of days from the start of construction.





DesignDefine cables and their trajectory in the beam.


select the slab


The program displays the ‘Magnel diagram’ at three locations along the span; these diagrams showthe possible combinations of prestress force and cable eccentricity that generate acceptable stressesthroughout the beam at all stages. The diagrams below are based on an estimated loss since thecables have not yet been defined and do not include the effect of secondary moments because themodel has not yet been solved for the added prestressing loads.

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The program displays upper and lower boundaries of eccentricity in which the centre-of-gravity of thecables must lie. Note that the boundaries are calculated based on the estimated losses.

Specify the loss parameters for individual cables:

click the icon in the main side menu and click the tab.

Define the cable trajectories:





There are several options:

by list : specify the straight segments and the program automatically connects them with parabolic segments:

click

The cable location is superimposed on the Magnel diagram:

define individual segments:

We will define the cable on one-half of the beam and then copy and flip it to the second half.

The half-cable is initially defined by 5 straight segments that are then joined by parabolic segments(the 5th segment is at the middle support).


Move the to the two points defining "Segment no 1" in the table above; repeat for the other lines.

Now connect the straight segments:


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Select two adjacent lines; the program connects them with a new segment and smooths the curve.

Repeat until one single cable is formed.

Copy the cable to the other half of the slab:



select the first straight segment (at the left support) and the last parabolic segment (to the left of thecenter support).

Specify the mid-point of the cable as the reference coordinate; click by coordinate at the bottomof the screen and move the to the following coordinates (or type in the coordinates directly):

The program copies all of the segments to the right half of the beam.




Index- B -Bridge analysis 104, 106

- C -Chess load 62

Combination groups 71

Composite beam 83

Concrete design 89

Contour map 69

Copy geometry 7, 30

- D -Dynamic 101

- E -Element mesh 19

- L -Light gauge steel 78

Load combinations 71

- M -Mesh 26

Moving loads 64

- N -Node grid 19

- P -Plane frame 7, 13

Plane grid 19, 23

Post-tensionning 111, 117

- R -Results 69, 71

Results along a line 69

- S -Space frame 30, 35, 41, 52

Springs 23

Steel design 74, 78

Submodel 30, 58

- W -Walls 41

Wizard 7, 30

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