Hello,
I am currently using abaqus to attempt to replicate tribology experiments I am conducting with pig aorta. The model is 2D with a circular indenter, modelled as a rigid body, pushing down and the dragging on a pig aorta imposed by contact between the indenter and top surface of the tissue. The aorta is modelled a two layer hyperleastic material joined by a cohesive zone with dimensions less than one hundredth of the dimensions of the two layers. The cohesive zone is a traction separation model, damage is modelled trough fracture energy and it is attached to the two layers by tie constraints. The bottom surface of the lower layer is fixed and the indenter has a load applied on the first step which is then maintained in the subsequent step whilst a displacement is applied to drag the indenter across the tissue. I am using a static solver.
The problem I have is that if I run this model the cohesive elements do not resist the compression but deform and the two layers of tissue appear to pass through one another, I have found a way around this by imposing general contact with an individual property assignment between the indenter and top surface. However this seems unnecessary and costly when from what I have read in the manual the elements should resist the compression.
The .inp is attached.
Thank you for any help you can provide
I am currently using abaqus to attempt to replicate tribology experiments I am conducting with pig aorta. The model is 2D with a circular indenter, modelled as a rigid body, pushing down and the dragging on a pig aorta imposed by contact between the indenter and top surface of the tissue. The aorta is modelled a two layer hyperleastic material joined by a cohesive zone with dimensions less than one hundredth of the dimensions of the two layers. The cohesive zone is a traction separation model, damage is modelled trough fracture energy and it is attached to the two layers by tie constraints. The bottom surface of the lower layer is fixed and the indenter has a load applied on the first step which is then maintained in the subsequent step whilst a displacement is applied to drag the indenter across the tissue. I am using a static solver.
The problem I have is that if I run this model the cohesive elements do not resist the compression but deform and the two layers of tissue appear to pass through one another, I have found a way around this by imposing general contact with an individual property assignment between the indenter and top surface. However this seems unnecessary and costly when from what I have read in the manual the elements should resist the compression.
The .inp is attached.
Thank you for any help you can provide