Hello everyone.
I am trying to do something with the deformation gradient in UMAT. I used F=DFGRD0 as the gradient. but i found that it always comes to be a identity tensor not only for the case of a 3d isotropic elastic material but also for the ramberg osgood model. it was very surprising for me so i also tried to print DFGRD1 it was also identity tensor.
I have used a C3D8 single element and was doing the uniaxial test. Please help me out with this
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The documentation says,
The documentation says,
"This array is set to the identity matrix if nonlinear geometric effects are not included in the step definition associated with this increment."
I hope that helps.
thank you very much.
thank you very much.
That was of great help.
thanks