Modeling Nanocomposite Piezoresistive Response With Electromechanical Cohesive Zone Material Point Method

In the current work, the Material Point Method (MPM) is extended to allow for interfacial discontinuities in problems with composite materials using cohesive zone (CZ) techniques. The proposed CZMPM is observed to result in smaller errors in the primary and secondary field variables, especially near the interface, for a given boundary value problem in comparison to the traditional MPM solution. The proposed CZMPM is used to solve an electromechanical test problem with a single fiber in the matrix medium. It is observed that the proposed CZMPM results in smaller local and volume averaged errors. The CZMPM is further used to evaluate the effective piezoresistive response of the nanoscale carbon nanotube (CNT)-polymer composite with electron hopping in between the nanotubes. The observed effective piezoresistive response exhibits features similar to those reported in the literature using finite element techniques for small strains. However, CZMPM allows for large deformations of the nanoscale representative volume element as presented in the current work.