cohesive elements between rubber and inclusions

[Heiner77]

Hi,

my problem is the definition of the debonding behaviour with cohesive elements (traction-separation) around an carbon-black inclusion in a rubber material, with ABAQUS v.6.6.

Thers´s no problem with the steps in CAE to define this behaviour, but the calculation stops with:" to many attemps were made for this approach..."

The minimum step size is 1E-09, beginning with a 0.001 step.

Could there be problems with the directions of the cohesive stack? I use sweep path for meshing these cohesive elements, the oriention of these elements are from the middle outwards, around the inclusion.

I´m not a english native speaker, but i hope the problem i have is a little bit clear (nice german-english ?

Regards

 

[xerf]

The message indicates that the problem is too non-linear to be solved accurately with the chosen (by ABAQUS) time increment. There can be various causes, including modeling inadequacies. Sometimes even if the modeling is done correctly, the problem is just too non-linear.

One cause might be the softening part of the cohesive-traction law which models failure of the cohesive elements.

Some common rules:
- You should try to limit the maximum time increment to a lower value such that the loading increment is not too big.

- If the displacements are large, turn NLGEOM to ON.