"Zero thickness" error in SOL 600 (Patran)

AI Thread Summary
The "zero thickness" error in SOL 600 analysis using Patran typically arises from issues with element properties or constraints, even if the model appears correctly defined. Users have noted that this error can occur when external thickness limits are violated, especially under thermal expansion conditions. Rebuilding the model has resolved the issue for some, suggesting that complex models with many parts may contribute to the problem. Additionally, hour-glassing in under-integrated elements can also lead to similar errors. Understanding the specific element types and constraints is crucial for troubleshooting this issue effectively.
uribemax2
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Hello all,

I am doing a SOL 600 analysis but Nastran gives me an error of "zero thickness" in some elements. Obviously, I checked those elements and they have properly defined their properties so I don't know what can I do.

I've done a lot of linear and nonlinear static analysis in that model and all of them have run okey, therefore I suppose that the model is well constituted, where could be the problem?

The model is all formed by Quad4 elements and Patran version is 2010.

Thanks in advance.
 
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I'm not familiar with Nastran, but other problem solvers give this type of error when the constraints are violated.

For example, the external thickness is limited to 0.010, and the layers add up to 0.010, but the external limit is violated when heat is applied, due to thermal expansion.
 
Many thanks for answering.

I tried to define constraints again but anything changed so I've rebuilt my model and surprisingly the problem has disappeared. I am working in a big model with a lot of parts and connectors so that could be the issue. It's a pity that I still don't know why it didn't work properly but now I can continue working so that's all.

Thanks for helping.
 
What kind of elements are you using? Sounds a lot like an hour-glassing problem that some under-integrated elements suffer from.
 
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