Hello guys,
I am working on an UMAT subroutine (ABAQUS) for the mechanical behavior of solid materials. I test the subroutine on 1 cubic element. All simulation is done in a condition that the pressure is applied on the surfaces so theoretically, all shear components are 0 (S12=S13=S23=0). Mostly, the shear components of stress tensor obtained by the subroutine are very small (fluctuation around zero with the order of 10^-9). However, sometimes, these shear stresses and strains are accumulated (Which should not be),then, attain a very high value and lead to the collapse of the model (stop at the middle of the calculation or give inaccurate results). To check the equations, I do a simple modeling in Matlab, I imposed the increment of shear components equal to 0 and the model works perfectly.
I am trying to solve this problem but I don't really understand the reason of this issue. If someones have experience with this problem, could you please help me with some advices?
Thank you in advance
Best wishes
I am working on an UMAT subroutine (ABAQUS) for the mechanical behavior of solid materials. I test the subroutine on 1 cubic element. All simulation is done in a condition that the pressure is applied on the surfaces so theoretically, all shear components are 0 (S12=S13=S23=0). Mostly, the shear components of stress tensor obtained by the subroutine are very small (fluctuation around zero with the order of 10^-9). However, sometimes, these shear stresses and strains are accumulated (Which should not be),then, attain a very high value and lead to the collapse of the model (stop at the middle of the calculation or give inaccurate results). To check the equations, I do a simple modeling in Matlab, I imposed the increment of shear components equal to 0 and the model works perfectly.
I am trying to solve this problem but I don't really understand the reason of this issue. If someones have experience with this problem, could you please help me with some advices?
Thank you in advance
Best wishes