Designing Connections in Autodesk® Revit® Structure to Drive BIM Models

to Fabrication

Doug EvansMichelle McCarthy

This class will focus on:– Manufacturing’s role in the BIM process– The basics of operating SDS/2 Connect– The code-based joint analysis involved in designing connections– Demonstrating how the Autodesk® Revit® Structure model can be

sent downstream for detailing. – Addressing audience questions and FAQ’s asked by newer users

Manufacturing’s Impact on BIM• Manufacturing concerns impact a structure throughout the

construction cycle, not just during actual fabrication– Bidding, Pre-construction, Design, Scheduling, Shipping, Construction

• Most are currently communicating with BIM models at a design level– Engineer to Fabricator– Using a BIM with LOD 200 at best

• If you’re interested in connection design inside Revit Structure, you’re interested in at least LOD 300

What is Level of Development ?

• Level of Development (LOD) is a description of the steps through which a BIM element can logically progress from the lowest level of conceptual approximation to the highest level of representational precision.

• LOD 100– Conceptual

• LOD 200– Approximate geometry

• LOD 300– Precise geometry

• LOD 400– Fabrication

• LOD 500– As-built

http://www.aia.org/groups/aia/documents/pdf/aiab078868.pdf

Manufacturing’s Impact on BIM• LOD 400 information can enhance the BIM in various areas

– Target Value Design (TVD) or Target Costing• A Lean Construction principle• Cost is a consideration in design and requires rapid cost

feedback– Integrated Project Delivery (IPD)– Improve Model based estimating

• Ties in with TVD• Detailed manufacturing info = more accurate estimates • Can perform cost comparisons

– Clash detection– Scheduling

Communicating with Manufacturers• Data loss and

misinterpretation

• Inefficient use of time recreating information

• Difficult to quickly compare alternatives

• Cost prohibitive

http://www.aecbytes.com/buildingthefuture/2009/ModelBasedEstimating.html

Communicating with Manufacturers• Quicker

turnaround• Take advantage

of all available information

• Design can be more fluid

• 80/20 Rule• Easier for

manufacturers to react and perform

http://www.aecbytes.com/buildingthefuture/2009/ModelBasedEstimating.html

Using Revit to Communicate with Manufacturing Tools• Manufacturers use many different tools in their day-to-day

operation– MRP– CNC– Field– Clash detection– Scheduling– In-house

• Design models and manufacturing models are DIFFERENT• How do you bridge the gap?

What is SDS/2 Connect?

• Add-in to Revit Structure developed by Autodesk Partner, Design Data

• SDS/2 connection design, complete with longhand calculation• Includes model roundtripping with the Revit Structure model• Overview Video

The Value of Connections in Revit• Quick access to connection design calculations• Value Engineering in Revit

– Quickly test connection scenarios• Full joint analysis• An API based model transfer between Revit and SDS/2 for BIM.

– Structural & connections– Works better than IFC or CIS2 for connections and structural

components

SDS/2 Connect Tour

SDS/2 Connect: Help Menus• Includes a connection guide• In-depth explanation for how

connections are designed in SDS/2 Connect

• Topics > Connections > Connection Design

SDS/2 Connect: Tools

• Options– Setup– Family & Material options– Revit Optimization

• Import CXL loads– Imports loads from CSC Fastrak– Settings for moment and shear loads– For Revit loads, SDS/2 Connect can use the stored in Revit Structure

Example of Setup screen for connection design

Video of CSC Import

SDS/2 Connect: Tools

• Edit– Edit a single connection through a user interface– Select nodes or connection materials to access interface

• Report– Generate calculations to verify connections– Expanded calculations with “show our work”

Example of expanded design calculation

SDS/2 Connect: Tools

• AutoStd– Applies connections to selected members – Can be changed to various connection types

• Design All– Will design all connections on a project– This can be limited to design only pre-designed connections

SDS/2 Connect: Tools

• Export– Exports the Revit Structure model to SDS/2 Detailing– Several options provide fullest control over export

• Import– Populates a new structure– Updates an existing model– Imports connections from detailer

Connection Design with SDS/2 Connect

Connection Design

• Framing Conditions• Connection Specifications• Loads• “Intelligent Connection

Design”• User Connections

Framing Conditions

• Auto Standard Connections– Based on Setup– Connection type is determined by

software• Specified Connections

– Chosen by user– System can override if necessary

due to erectability or clashing• http://youtu.be/VFRfEabwH9A

Loads

• Loads can be input or automatically set• Loads can be imported from CSC Fastrak• If loads are stored in Revit Structure they can be used

– Revit currently only stores shear loads• Changing loads may affect:

– Bolt Diameters– Plate thickness & size– Weld design– Number of bolts

• http://youtu.be/FEjd_f4Kjps

Connection Specifications• Gives users added control over:

– Safety Connections– Attachment methods– Near/Far side attachments– Many other connection variations

• http://youtu.be/hF3FKQHSE1w

Intelligent Connection Design• Considers fit-up and

constructability as a part of connection design– System will help redesign

connection when possible• Changes in framing condition

cause connections to update automatically

• http://youtu.be/qGjIxbH9I7M

User Connections

• Override system designed connections

• Meet specific design requirements

• Cross-dependent entry fields update items related to the original change

• http://youtu.be/21RCcUUIaHY

User connection fields become editable with check box

Examples of more complicated connections

SDS/2 Connect: Technical Details• Initialization of the SDS/2 Connect Add-in will modify Revit

Structure families– Enables material operations necessary for connections, like copes– Post-initialization, the file can be saved as a template, saving time

on future projects.• Custom Families are not addressed during initialization

– Usually have to be manually mapped• Check Project

– Find undesignable members– Searches out and identifies any material that hasn’t been mapped

• Custom Families are mapped by the user via the Material file Mapping tool

SDS/2 automatically modifies families during initialization. Users have access to map materials for some families manually.

SDS/2 Connect: Technical Details• SDS/2 Connect modifies these families:

– Wide Flange– L-Angle– LL-Angle– W-Tee– Channel– HSS Rectangular– Pipe– HSS Round

• Modifications include adding the ability to add copes and other connection related material operations

SDS/2 Connect: Technical Details• SDS/2 Connect adds these families:

– Plate– Angle– RoundPlate– Bolt– StandardBolt– StandardBolt Array– BentPlate

• Specifically related to connection materials

SDS/2 Connect: Technical Details• Tips for improving Revit Structure performance:

– Avoid fine grain views– Skip generating bolts

• Connections are still designed with bolts, simply not shown to speed up the model

– Holes and welds are not shown in Revit Structure• Connections are still designed to include this information and will

be visible once sent to SDS/2 Detailing

Welds are not shown in Revit, but are included in connection design

Potential Workflows with SDS/2 Connect

Connection Sketches

• Sketch Tool– Quickly generate

connection sketches– Design calculations are

automatically provided– Tags for some connection

materials are available• Create sketches from the

actual model• Create sketches from

modeled framing conditions

Connection Scenarios• Create connection

scenarios– Quickly access

calculations– Test various

configurations– Choose best connections– Perform target value

costing/design• In this usage of SDS/2

Connect is simply a connection design aid

Workflows

• Three “Paths” for Model-Based Connection Design– SDS/2 Connect can perform a one time model transfer like IFC or

CIS/2• Currently only includes major structural members and

connections– Export model as a starting point for Detailer/Fabricator (D/F) to

design connections and be imported back to Revit Structure– Engineer designs specific connections that will appear in D/F model

upon import• Could be 10% of connections or 100% in the structure

Round-Tripping

• Round-tripping provides opportunity for communication through the model– Better way to maintain

model integrity– Improves communication

through models• Integrates manufacturing-

level information in the Revit Model– Brings you closer to LOD 400

• http://youtu.be/2wdbLCjT1fs

Connection Optimization for Design• Aesthetic vs. Structural considerations

– Union Pacific building in Omaha, NE• Expansive glass façade• Oversized Gussets required by design

block natural light• Can be avoided with early connection

design and optimized connections• Vital in TVD or Target Costing

– Cost savings on smaller section sizes may be lost when it comes time for connections

• Doublers, stiffeners and welds add up!

– Video example

Optimizing Connections for Manufacturing• Material choices matter!

– Bolted vs. welded– Stock materials

• Example: Design calls for some shear connections to be 3/8” thick and some ½” thick. The fabricator may have surplus ½” thick bar stock and request that all shear connections are ½” thick. While they may be a little overdesigned, they can be manufactured at a lower cost.

• Engineering software may design structures choosing a variety of section sizes that may not be optimal for ordering. – Choosing same depth sections when possible to optimize mill order– SDS/2 links to MRP products that look at inventory schedules and

can see what steel is readily available and what requires a mill order– This can also help shorten timelines

Optimizing Connecitons for Manufacturing• The Rise of Shop Technology

– Becoming more like the auto industry– CNC equipment & Robots

• The influence of new technology vs. old– Example: WTee Shear connections

• Hole locations vary based on beam web thickness

• 5 1/2” Gauge is constant, but hole locations shift side to side

• CNC technology enables these connections to be efficiento These connections would slow

down shops that do not have CNC

Pre-Construction Bids and BIM• Engineer exports design model via SDS/2 Connect to

Detailer/Fabricator’s SDS/2 model.– Once imported to SDS/2, advance BOM’s can be obtained in minutes– Connections are immediately designed, revealing opportunities for

value engineering– Changes to the structural model can be made and updated anytime,

allowing for a quicker response

Pre-Construction Bids and BIM• Communication between pre-construction and as-manufactured

models impacts:– Accuracy of material take-offs– Elimination of duplicate information– Shorter turnaround from design to fabrication– Value engineering starts earlier in the process– Detailing can start earlier in the process (Early Steel Detailing)– Immediate feedback with connection calculations– Reduces steps required to obtain shop drawings

SDS/2 Connect Frequently Asked Questions

SDS/2 Connect: FAQ’s• Difficulty applying and designing connections

– 3 common causes / solutions• Export Warnings• Revit Loads• Tagging

SDS/2 Connect FAQ:Designing Connections• Beam or column is not recognized as a connectable member

– Structural usage is not set correctly– To verify this, use “Check Project” command to locate undesignable

members– Correct structural usages

• Beams: Girder, Joist or Other• Vertical braces: Vertical Bracing• Horizontal braces: Horizontal Bracing

SDS/2 Connect FAQ: Designing Connections• Families may have been incorrectly modified

– Common when using custom families• May not have been recognized during initialization

– This is corrected through the Material File Mapping window in setup• Select custom family• Choose section type• Material file source • Sections to be mapped• Select “Modify this Family” check box

SDS/2 Connect FAQ: Designing Connections• Structural failure

– SDS/2 Connect will not design connections when:• The desired connection isn’t physically possible

o Setup options like maximum plate thickness, max bolt diameter can come into play here

o High loads require more rows of bolts than the beam can hold

• The connection can’t be erected• A connection is not yet supported

– This can be overridden to some extent in SDS/2 Connect and fully in SDS/2 Detailing

SDS/2 Connect FAQ: Export Warnings• “Project name is current against this file”

– User has exported the model twice containing no changes between the two exports

• Exports generated without importing an update between them• Update was imported, but contained no changes

– More commonly, Libraries are set up incorrectly• This issue is common in Revit Structure 2012

SDS/2 Connect FAQ: Export Warnings• Open Options in Revit, select the File Locations tab, and choose

Places– Library names should be:

• Imperial Library• Metric Library

SDS/2 Connect FAQ: Revit Loads• SDS/2 Connect can import member end and moment loads from

CSC’s Fastrak Building Designer• SDS/2 Connect can read member end reactions stored in Revit

Structure– Newer feature to SDS/2 Connect– Shear loads for beams are the only load that Revit Structure stores

currently

SDS/2 Connect FAQ: Tagging• Users can tag plate descriptions and angle sizes only

– Done via a unique family created by Design Data– 2013 version will include the tag families by default– 2013 version will also add simple bolt descriptions– Currently you can email support@sds2connect.com to get the family

• For more detailed drawings of connections, the model can be sent to SDS/2 Detailing

SDS/2 Connect: 2013 Enhancements• WTee and Channel are added as connection materials

– Channel column splices– Smaller Vbrace connections– WTee shear connections

• Connection Find tool – Searches & filters connections according to certain parameters

• Bolts can be created individually

Questions?

Doug EvansMichelle McCarthy