Modelling for Integration
Ralph Pullinger, Structural Technical Specialist, Autodesk, AEC Division (Northern Europe)
SE4244
Learning Objectives
At the end of this class, you will be able to:

Understand the complexities of the Revit® Structure analytical model

Make decisions confidently and assign responsibilities for model generation

Learn to make compromises but know who will ALWAYS win out
About the Speaker
Ralph is the structural technical specialist for Autodesk, Northern Europe. His expertise
includes AutoCAD®, Autodesk® Revit® Structure, AutoCAD Structural Detailing and Autodesk
Robot™ Structural Analysis. Previously, Ralph had spent over 20 years in industry with over 15
years at W A Fairhurst & Partners, the largest multidisciplinary private partnership in the U.K.
Ralph is a structural engineer first, but has sat on both sides of the fence having managed CAD
systems in the past. Ralph is now taking this knowledge and expertise gained over the years
and applying it to the situations today’s consulting engineers sometimes find themselves in. His
time on the road includes visiting distributors, resellers, and customers across Northern Europe
and training them in all of the Autodesk structural applications and general integration
techniques.
He can be contacted at ralph.pullinger@autodesk.com
Class Summary
Learn the ins and outs of the new analytical model within Autodesk® Revit® Structure 2012.
This class covers how to model effectively for bidirectional integration with Robot™ Structural
Analysis Professional and any third party analysis application. This class is important for both
engineers and modellers and is ideally suited for today’s new breed of engineer.
Modelling for Integration
All is not what it seems!
Spot the differences (there are eight in total)
Why a child’s puzzle as an opening? Pay attention and you shall see!
Analytical Examples
The following examples are all taken from real support issues.
Stepped slab
Can you spot any differences between the first figure and the second?
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Modelling for Integration
It is NOT that one has a section line!
The plain truth is that visually there is none, but analytically it is a different story.
The first set of slabs was modelled using a wall to connect the two whereas the second was
modelled using a beam.

Walls are good – when used correctly

Beams are better – in certain situations

Projecting the analytical line of slabs needs to be monitored
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Modelling for Integration
Slab on four walls
There is a theme developing: compare the two figures first and then look at the analytical
solution.

Default behaviour of walls is not always good

Consistency when attaching walls to floors is important

Walls must be modelled so that the outside IS the outside
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Modelling for Integration
Column and Beams

When is a wall not a wall?

Who knows what a rigid link is?

Is this engineering or modelling?

Revit settings still apply
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Modelling for Integration
Analytical Settings
Having just mentioned those settings it is possibly best that we remind ourselves of them.

Automatic checks

Tolerances

Member Supports Check

Analytical/Physical Model Consistency
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Modelling for Integration
Sloping beam
What could be easier?
Watch what happens when the analytical alignment of the beam changes.
The left column remains within tolerance and keeps the join whereas the right column goes out
of tolerance and reverts back to its default behaviour.
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Modelling for Integration
After some manipulation the analytical plane can be almost anywhere.
 Analytical control is quite complex, however, it can be quite rewarding

Flexibility is the key
Grid systems
Have you ever had this happen? Very typical when using rectangular columns set out on the
edge of the slab. The last beam in a row (or column) slopes – not ideal and one that the
engineer should spot straight away.
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Modelling for Integration
With some manipulation the analytical lines can be harmonized into the simple stick model
engineer’s love.
Doing this using the controls built in is achievable but you need to know what you are doing.
 Sometimes there can be too much flexibility and too much time can be wasted
There must be a better way surely?
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Modelling for Integration
Overall Observations

If entered blindly the integration process will fail

The key to integration is communication

It is essential that Engineers understand modelling and that Modellers understand
engineering

There is lots of flexibility

If there is an impasse then the model wins as the project must be documented
Analytical Adjustment
There is a better way – but you need to watch the video that accompanies this hand-out that is
available online.
Extending Integration to Documentation
If you have taken the bold step of doing more in Revit Structure from an analytical standpoint
what not consider using the engine to help drive the loading process and manage any changes
that may occur?
 Consider adding loads

Locking them to elements

Load flexes with elements

Do engineers need to be modellers?

Do modellers need to be engineers?
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Modelling for Integration
If the loads (area and line) are locked to the walls then as the walls move and flex so do the
loads. In a changing design this could save considerable time.
Documenting Loads

Create fills based on use

Add comments to the loads

Annotate loads to display their comments

Aids internal and external documentation

Very useful check!
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Modelling for Integration
Robot Link
The link has moved for 2012. It can now be found on the Analyze (why not Analyse?) ribbon.
Two basic processes: export or import with an option to use a file if it is not the same
workstation/user.
There are certain settings that need to be understood. I am not saying these are best – they
just work for me as an engineer and modeller.
How does the integration process work?
 First pass – Robot model is created from scratch

Engineer adds loads, combinations, ‘technical’ stuff and design

Robot model returned to Revit for update with new member sizes

Second pass – Robot model is merged with Revit geometry

Engineer does their thing again

Robot model returned etc.
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Modelling for Integration
What many people fail to understand is that there are two models: a physical model and an
engineering model. This is understandable as Revit (as clever as it is) does not have any idea
of seismic or time history loads. If you use a file based transfer protocol then it is essential that
the file name remains constant.
If you want to know where to find this file have a look under project parameters.
Summary
In closing I would just like to remind you that:


There are two personas
o
An Engineer
o
A modeller
Some have split personas
o
The ‘new breed’ (who are really a modern ‘old breed’)

It is important that the integration process is understood by all

It is vital that information is managed
o
i.e. who does what, when

It is not rocket science!

Thank you for being here and enjoy the rest of AU!
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