Hello,
I'm facing a problem when pressing an analytical rigid flat surface against a rubber block in Abaqus Standard (2024).
My general model setup:
I'm running Static Steps with Nlgeom=yes, unsymm=yes. I defined a rubber block with hyperelastic Yeoh material model and viscoelasticity. The frictionless contact between rubber block and analytical rigid surface is described using contact pair, surface-to-surface discretisation and penalty contact (with default penalty stiffness). I'm using C3D8H Elements.
Loading and boundary conditons:
Over the whole simulation the rubber block's top surface is held fixed (BC: Encastre). Then, in the first step, the analytical surface is displaced against the rubber block, using a displacement boundary condition. During this step, all degrees of freedom of the analytical surface are fixed, except of the moving direction. Everything is working here, Cpress is interpretable, and the artificial energy (ALLAE) is very low (but not zero). The applied displacement corresponds to around 70N on the reference point of the analytical surface. Then, in the second step, I apply a force of 10N (CLOAD) on the reference point of the analytical surface to get the results of contact pressure cpress for 10N normal load. This simulation is running to an end too, but the results look weird. There are some stress peaks as could be seen in the cpress plot, furthermore some elements show hourglassing-like behaviour. ALLAE is rising to the end of the step until ALLAE>ALLIE at the end of the step. I'm a bit confused why this problem occurs with lower loads.
I hope someone can help me and give some hints
Thank you very much.
