Cad for Fabric Structure design.

[CaptainBob]

Does any one know of a CAD package for Fabric design, tents or air supported structures.

Do you think a CAD program for light sheet metal design would work?

I also would like to do some FEA for wind loads on the stucture.

Thanks,
Bob

 

[JWB46]

You could try looking at

http://www.arcaro.org.

Good luck.

 

[cowski]

Not quite sure if this is what you are looking for, but Unigraphics (EDS) has an add-on module for composite design. You model what shape you want in 3D, then this program can output what the sheet will be in 2D. I have not personally used this software so I cannot comment on how well it works, but it may be worth investigating.

http://www.eds.com/products/plm/unigraphics_nx/dpd/composites.shtml

 

[ewh]

The composites package was developed by Boeing and was turned over to EDS to market and maintain (if my memory serves). Our company was looking into purchasing this package, but ran into some problems during evaluation, which probably could have been overcome. However, we were informed by EDS that they were terminating their support of the software, so naturally we did not pursue it any further. I don't know if it is being offered anymore; apparently there were not enough sales to justify any further development.

 

[MadMango]

Textile houses use CAD for cloth layout and automated cutting. Some programs you can try searching for are:

PAD
OptiTex
Gerber Accumark
Nester

When you mention "tents and air supported structures" I tend to think you are talking about hot air balloons and inflatable kiddie jumpers. The above programs probably won't help you there.

I would think any mainstream CAD system (SolidWorks, Pro/E, SolidEdge, etc) should be able to model what you need. As for FEA, I think if you used shell elements and applied the proper material properties you will get some useful results. Jsut remember that most CAD packages don't have built-in FEA software, so that will be an additional cost over and beyond the CAD system itself.

MadMango
"Probable impossibilities are to be preferred to improbable possibilities."
Have you read faq731-376 to make the best use of Eng-Tips Forums?

 

[paron]

The sheet metal program could work for unfolding the sheet into flats. However, the sheet metal program would not prevent you from designing structures which would not inflate to the shape you designed.

If you are an experienced inflatable designer, I am sorry for belaboring the obvious, but I guessed that this thread might be found on a search by someone who isn't so experienced. For the latter:

Since inflatables are strictly tensile structures, they will always have a cross-section which is circular. I can't even begin to tell you the number of designs I saw that featured flat surfaces and square corners which were intended to be maintained in that shape by internal pressure. Perfectly acceptable sheet metal design, totally bonkers as inflatable design.

Another thing that makes sheet metal patterns different than inflatable patterns is the strongly anisotropic nature of most materials used for inflatables. Sheet metal is almost the same in all directions; certainly it is more so than square-woven nylon with urethane coating. So, you will have to watch the warp direction of the fabric and tweak the shapes to allow for stretching on the bias.