Gradient based cohesive zone models

Hello,

Strain gradient based (non-local) plasticity and damage models have been studied quite extensively in the literature.

 I was wondering if anyone has experience in the development of cohesive zone models that obtain the tractions in front of crack tip not only as a function of the diplacement jump, but also as a function of the gradient of displacement jump.

 If yes, can you please point me to the reference?

 Also, in the case of strain gradient plasticity, the numerical implementation is not straight forward and requires discretization of the consistency condition. On these lines, does any one have experience in the numerical implementation (are there any issues involved) of gradient based cohesive zone models?

 Thanks for your time,

Mohan Kulkarni