pure deformation of linear elastic body

Thanks for your reply, Dr. Jorgen

Sorry for my unclear question. I really need your help. Since I

would like to let you understand my situation, I try to make detailed

explanations as follows.

First, I want to perform the FE simulation with ABAQUS/Explicit

based on a rate form of a constitutive model. So I understand this model

is a relationship between the objective stress rate and the stretching

tensor. Simply speaking, this model can be derived from the hypoelastic

material. I can not change the model.

I wrote a user material subroutine based on the model and perform

some simualtions. It works under a tension and a compression, BUT I have

a trouble on a pure shear. Even if I do not consider the plastic part,

i.e. the model is for a pure elastic, I still have the trouble under the

pure shear. I attached the subroutine.

I read the subroutine again and again and for many times. I could

not still found my mistake.

Im so happy if you will help me.

Oh, I see. Your modeling framework sounds just fine. My suspicion is probably the same as your, that there is likely some bug in the model implementation. Unfortunately, debugging a VUMAT is a very time consuming activity, and I simply dont have the time for that work as part of my free support.

Send me a private message if you want to discuss professional (payed for) support.

- Jorgen