Hello everyone,

I started to learn Abaqus for my Thesis in which I have to simulate concrete beams with X-FEM (Abaqus Standard). I found two sources about the possibilities of crack simulation (propagating cracks):

1.) VCCT 

2.) CZM 

In the first source they say that CZM = cohesive segment method and that within the CZM there are 2 options: 1.) interfaces (element based) and 2.) contact (surface based). 

In the second source (Abaqus website) they say that there are 3 options within cohesive modelling. 1.) Traction separation cohesive behavior = cohesive segment method 2.) interfaces and 3.) contact. So here they say that the cohesive segment method is a 3. method beside the interfaces and contact. But in the first source they say that interface and contact are sub categorys of the CZM. 

Now I am not sure if there exist 3 possibilities for cohesive crack modelling or just 2.

Thank you in advance!:)