Cohesive zone parameters - Carbon nanotube Polymer interface

Hi everyone

I have a question regarding cohesive zone models/laws/parameters for the interface between carbon nanotubes and polymers.  There seems to be a handful of literature on obtaining tangential (shear) cohesive zone information for this type of interface.  For example, there are a couple of experimental and molecular dynamics simulations I have found that try to obtain the cohesive zone parameters for shear.  The problem is that they are all for nanotube pullout which means that they only obtain the shear information.

Does anyone know where I could possibly get information regarding NORMAL cohesive zone parameters for carbon nanotube polymer interfaces?  Or, could anyone give me an indication of how to relate the shear cohesive zone model to the normal cohesive zone model ?  Is there a kind of assumption that is made regarding the normal work vs the shear work etc.?

I am trying to model a carbon nanotube pullout of a polymer matrix in Ansys but cannot find reliable information for the normal cohesive zone parameters.

Any help would be appreciated.

Kind regards

Bevan Smith

Wits University

Johannesburg