Thursday, January 6, 2011

Structural Analysis Interoperability


I am interested in hearing other peoples experiences with Revit Structure and Structural Analysis packages.


In the past I have trialled E-Tabs, and found that the interoperability wasn't great, whilst we could import an E-Tabs model into Revit, the member sizes did not come through correct, and vice verca.
I have had some very good feedback regarding the use of Robot, although I understand that Robot does not do certain analysis that is required on some projects. Obviously being diverse with your choice of analysis software is critical.

I have used CSC Fastrak successfully to create a very 'rough and ready' set of documents for value engineering.

The model was constructed in Fastrak, and exported into Revit, all members came through into Revit correct, and it meant we were able to value engineer a 6 storey steel frame with a turn around of maybe 1 days work for the engineer and half a day for the Revit modeller.

One problem I can see with using analysis packages as an interoperable solution is the requirements for each model.

A structural engineer needs to produce a 'rough' model for structural analysis, maybe with an accuracy of 100mm... or more? The analysis model doesn't need to be as accurate as the Revit model.

Another problem is the Revit modeller will need to have an understanding of how an analytical model needs to be constructed, and be aware that by doing things such as running a concrete beam past another concrete beam, then using an opening by face to tidy the beam join up, could have an impact on the analytical model, if this process isn't done correctly.

I would propose that if the time constraints permit, the analytical model is produced first in design stages and an export to Revit is used for preliminary documents, until the Architects design is set.

Once there is a requirement for Construction documents, the Revit model should be constructed in parallel with the analytical model, given the tolerance required for each model, I don't think it is practical to use an 'interoperable / bi-directional' model for analysis and documentation.

I would be interested to hear other peoples thoughts on this subject.

2 comments:

  1. Hi Glen, your comments are all things I'm considering having just purchased Revit. My intention is to use Revit to produce a structural model before the analytical model is produced, then pass my model to an engineer to import into the design software. This would suit the way I work at the moment i.e. I usually produce a basic structural package of drawings based on the architects preliminary scheme from which an engineer can firm up actual section sizes and produce design calculations. I suppose it depends on how companies approach the design and development of a project?
    Happy New year, Mick T

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  2. At the company I work; I use Revit Structural 2009/2010/2011 (all depends on what version our client was using) and the engineers use RAM Steel most of the time. We do use the RAM/Revit link and found that it is easier to start a project in either Revit or RAM and export / import just one time. Going back and forth is very cumbersome since RAM doesn't use anything similar to Revit's worksets (which we use in every project - and RAM resets the whole project/updated components to "workset1") and RAM needs to have the columns start/stop at each floor. RAM also need to have all of the concrete properties filled out in the "mappings" file.
    There is also a RISA/Revit link, but I have no experience with that.

    Thanks,
    Michael B

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