Hi,

I've got couple of questions about implementation of a constitutive law for cohesive elements using VUMAT in ABAQUS. I thank if you answer them, my questions are as follows:

1) If we wanna implement the traction-separation law; is that correct to consider the following?

S33=tn; S13=ts; S23=tt

2) Please confirm whether it is correct to state that strain components are equal to displacements?

3) How to define the separation? I mean do I have to consider element deletion like for bulk elements?

4) If my assumptions in questions 1-3 are correct, I am wondering that there is no necessity to use cohesive elements, I am curious to know the importance of using cohesive elements in this case. 

Thanks for your help in advance. I am looking forward to hearing from you.

Regards,

Mehdi