Hello, I run two similar NASTRAN solid composite elements models with sol 400 and LNSTATICS and I obtain different stress results. Why is that? Below are details about the models

The only difference between the two models is that for one, I specify a failure model thanks to "MATF" and ask for the strength ratios with "PARAM,SRCOMPS,YES".

Doing that, I obtain a 40% higher stress.

I have made sure that SR>>1 so that progressive failure or yielding can't be the cause of that.

I also compared the files to ensure the mentioned differences were the only one.

The files are linked bellow

Attached Files (4)

solidcomp.bdf.zip

solidcomp_failure.dat

solidcomp_failure.bdf.zip

solidcomp.dat

0 dbarlam over 3 years ago

The problem You run is bending dominated. You should run it changing SLCOM L -- to SLCOMP ASTN. Then You will see the same results

I ran both (with MATF and without MATF) . The results are identical.
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0 vincent.dor over 3 years ago

Yes, I am aware that I should use ASTN, this is precisely done in order to compare the two. But since both problems are using SLCOMP L, shouldn't they give the same results?
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0 vincent.dor over 3 years ago

MATF properties are only for failure, how do they affect the results when failure is not reached? I understand the results may not be good with PCOMPLS L but at least shouldn't they be consistent?
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0 dbarlam over 3 years ago

The SOL 400 NLSTATIC (NLSTEP , 1 increment only) run provides identical results for both with MATF and without MATF

In my opinion (in spite what is written in the QRG) the MATF You can use for Nonlinear Analysis only.
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0 vincent.dor over 3 years ago

thank you for your answers
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