Good day!

I am trying to perform a quasi static indentation simulation. I have this geometry, the total diameter of the specimen is 50 mm.

The red material (matrix) is TPU95A (A hyperelastic material) and the black material (platelets) is Tough PLA.

I am using hybrid elements C3D4H for the TPU95A and incompatible elements for the Tough PLA. The matrix that surrounds the platelets has an element size of 0.4 mm, the matrix between the layers, has an element size of 0.5 mm and the platelets has an element size of 0.8mm.

The simulation has two steps, the first one with the advance of the indentator (6 mm) and the step two, with the return of the indentator (7 mm). I am obtaining excessive distortion of different elements, especially the elements of the TPU95A and in the beginning of the step 2.

The kinetic energy does not exceed the internal energy.

The union between the two materials is defined with cohesive surfaces. 

Someone knows how can I fix this?

Thank you :)