Hello everyone.
I'm doing simulation about impact on composite using cohesive element. I have composite (0/90/0) which were modelled throug their thickness with C3D8R, while COH3D8 cohesive elements were inserted at the two interfaces between layers with different orientation. Interaction between intender and plate is surface-to-surface contact. After caculation, my cohesive element is distorted like this.

Can someone help me solve this problem ?
I'm doing simulation about impact on composite using cohesive element. I have composite (0/90/0) which were modelled throug their thickness with C3D8R, while COH3D8 cohesive elements were inserted at the two interfaces between layers with different orientation. Interaction between intender and plate is surface-to-surface contact. After caculation, my cohesive element is distorted like this.

Can someone help me solve this problem ?