Learning Forum

[munkhunur]

In case of using Bilinear isotropic hardening in ansys cyclic loading how can I assume strength degradation in here?

[Bhargava Sista]

I'm not sure what you mean by strength degradation so let me provide some relevant information. One way of looking at it is to see the accumulated plastic strain. You'll need to use user-defined result to plot NLEPEQ to plot this quantity. This tells you how much plastic strain is accumulated over the cycles of loading.nAlso, note that in cyclic loading the material experiences Bauschinger effect which is not captured by isotropic hardening. This is something you may want to consider in assessing strength degradation.n

[munkhunur]

Dear bsista,nI appreciate that you spending your precious time with me here. The firs of all, I would like to provide a brief information about what I do here. nI am simulating a cantilever beam under cyclic loading. But there is many questions are arising here. For example,nhow to plot Load-Displacement hysteresis loop from results?nYour right I want to result Bauschinger effect but it is not shown why? How can I plot such kind of nice loop as shown below? n I tried 4 different plastic material in my simulation. Here i want to show you one by one. nWhen I use multi linear isotropic hardening material with true stress, the simulation is terminated after several load step. How can I continue without error?nWhen I use multi linear kinematic hardening material with true stress, the simulation was successfully done. But result was not what I am looking for.nWhen I use Bilinear isotropic hardening material with 1025 MP tangent modulus , I could find relatively good loop compare with others. But there is Bauschinger effects was not match with experiment results. Dashed line indicates simulation here. nBKH i did not try to do here.nI have questions:nIn order to plot load-displacement curve in this cantilever beam, I used the command a probe-deformation-Y direction selection. Then I did Equivalent von mises with this directional deformation correlation as show above figures. Is it correct or not please tell me. I did not understand that NLEPEQ command to use here. Could you please give me little explanation about that? what reason can I use that?nTo fix that strange knees in the loops, should I use chaboche kinematic hardening material? If I do not have chaboche material test results which needed to get parameters, can I simulate material test under cyclic loading in ansys approximately? In this cas how can I do this test simulation?nI really appreciate that you giving any time to answer my crazy questions. Sorry I am a really fresh in the ansys and plasticity of material. Thank you thank you.nBest regards,nUNUR from Japan.