Modeling a Wire in Non-Linear FEM

[Burner2k]

Trying out a simple model in Nastran. Basically intent is to demonstrate geometric non-linear effects on a wire subjected to transverse load. The wire is hinged in both sides. I want to capture the membrane stiffening effects due to geometric non-linearity. Initially, I was modeling using CROD but the 106 analysis failed to run. I need to re-read the Non-linear guide, but I think 106 does not support PROD/CROD in 106 solution?

Then tried CBEAM and I was able to run the analysis correctly. Anyways, was curious to find out if I can do a better setup than the above. Perhaps using a different element which can capture wire physics more accurately in non-linear. Would CGAP might be a better option? Not sure if Gap elements are effective against transverse loads.

I intend to do a better research on the above coming weekend. Anyways, posting here to get a flavor from folks with experience in non-linear analysis.

 

[rb1957]

I don't think a gap element will do what you want.

Not surprised a ROD didn't work. Even though you "know" the "cable" reacts tension, there are internal moments which'd cause a ROD trouble.

It sounds like you're modelling the "cable" as a set of three force members, which may be a way to check the FEM solution ?

I think all the NASTRAN BEAM elements have the same underlying formulation, so they should give essentially the same result.
I don't know if ANSYS or SW have a stress based BEAM element ?



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