Indentation + pull-off using BilinearMixedModeCohesiveZoneModel UserObject in axisymmetric contact

[asurovi]

Hi all,

I am implementing adhesive contact using the BilinearMixedModeCohesiveZoneModel UserObject.

• I have done verification study of (pull-off only) adhesion between sphere and flat using BilinearMixedModeCohesiveZoneModel.
• In a standard 2-block configuration, the setup works as expected: indentation followed by pull-off runs smoothly.
• In contrast, for an axisymmetric sphere–flat contact, the CZM UserObject appears to support only adhesion (pull-off). The combined sequence of indentation followed by adhesion does not converge.

Question:
I would like to confirm whether there are any specific requirements or limitations when applying "BilinearMixedModeCohesiveZoneModel" in axisymmetric complex geometries, especially when transitioning from compressive contact to adhesion.

Follow-up Question:
My current understanding is that the penalty_normal_pressure Auxvariable corresponds to the contact pressure. If so, is it appropriate to use a NodalVariableSampler VectorPostprocessor to extract the nodal x-coordinates associated with this pressure field in order to determine the contact radius?

Any clarification on these two points would be valuable.

Thanks in advance!

[lindsayad]

@jiangwen84 would you want to weigh-in here? I see there is cohesive zone development happening in #31698