How does one specify penalty stiffness k in cohesive elements? 1

[Smozzy]

I am modelling delamination in composite laminates by creating cohesive elements, thin enough to assume as the resin rich regions. I would like to specify the penalty stiffnesses (K1, K2, K3) but cannot find a way to do so.

I have found it is possible to do so using the interaction property when specifying the traction-separation law in the interaction module, which is useful when modelling the delamination without cohesive elements,
however I need to be able to do so using actual elements between the plies.

Any advice in achieving this would be appreciated!



I have defined the following in the material data:
Elastic type: traction
E/Enn , G1/Ess and G2/Ett have been specified as well

QUADS damage; nominal stresses have been specified

Damage Evolution:
Type: Energy
Softening: Linear
degredation: Maximum
Mix mode behaviour: BK
Mode mix ratio: energy
power: 1

Fracture energies for epoxy: 0.1, 0.5, 0.5



The sections have been specified with a traction separation response