In ANSYS APDL, for modelling mode-I fracture simulation of an isotropic material, I am trying to use a concentrated key-point at crack tip along with a cohesive element along the crack path. The concentrated keypoint has a mesh surrounding it with PLANE183 elements which have quarter point nodes. Along the anticipated crack path, I am using cohesive element INTER203. I would like to know if it is correct to model a specimen in this way.