Which shell element is capable for elasto-plastic analysis?

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TPdct
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Which shell element is capable for elasto-plastic analysis?

Post by TPdct » Fri Dec 09, 2016 7:57 pm

I modeled a cantilever beam with ShellNL elements. The model has 2100 nodes. When I use elastic material, the computation is very fast and the result is correct, but when I change the material to J2Plasticity material, the computation is so slow and terminate when the material yields. The computation result of elastic stage is fine.
So which shell element is capable for elasto-plastic analysis?

fmk
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Re: Which shell element is capable for elasto-plastic analys

Post by fmk » Tue Dec 13, 2016 3:47 pm

all the shell elements are .. most assume small disp, the shellNLDKGQ takes into account large displacement. the issue you are having relates to the material and not the shell .. does the aplication just quit or does the analysis fail?

TPdct
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Re: Which shell element is capable for elasto-plastic analys

Post by TPdct » Tue Dec 13, 2016 6:11 pm

The application doesn't quit, but the analysis doesn't converge, I have tried all test method, including EnergyIncr, NormDispIncr... and different algorithm including KrylovNewton, Newton, BFGS... The integrator is Displacement Control. When the displacement I imposed is small, it works well, but after many analysis steps when the displacement is relatively larger to make the material begin to yield, it begins to have convergence problem.

TPdct
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Re: Which shell element is capable for elasto-plastic analys

Post by TPdct » Tue Dec 13, 2016 6:21 pm

The material I used is:
nDMaterial J2Plasticity 99 166666666666 76923076920 200000000 250000000 1 1
nDMaterial PlateFiber 100 99
section PlateFiber 4 100 0.01

dgale
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Re: Which shell element is capable for elasto-plastic analys

Post by dgale » Wed May 08, 2019 9:29 am

I have the same problem. Did you fix the problem,TPdct?
Could anyone write a tipical values for H and delta parameters for steel or aluminium?

Thanks guys!

vpapanik
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Re: Which shell element is capable for elasto-plastic analysis?

Post by vpapanik » Wed Apr 08, 2020 12:06 pm

I am experiencing exactly the same problem with J2Plasticity material.

vpapanik
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Re: Which shell element is capable for elasto-plastic analysis?

Post by vpapanik » Thu Apr 16, 2020 6:50 am

It is now corrected in the latest source code.

alfonsogdr
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Re: Which shell element is capable for elasto-plastic analysis?

Post by alfonsogdr » Mon Jul 13, 2020 10:23 pm

I am modeling a steel plate with shell elements and J2Plasticity material and I still have the same problem. It is corrected for sure?

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