Computational Micromechanics Analysis of Damage Induced Piezoresistivity in Carbon Nanotube-Polymer Nanocomposites Under Cyclic Loading Conditions

Abstract

The current 2-scale computational multiscale micromechanics based exploration of sensing capabilities in carbon nanotube (CNT) polymer nanocomposites focuses on the macroscale piezoresistive response when the nanocomposite undergoes damage. It has been shown that electron hopping at the nanoscale is the primary mechanism behind the observed macroscale piezoresistivity for such nanocomposites. A novel continuum description of the non-continuum electron hopping effect used in the current work enables the use of multiscale continuum micromechanics based approaches to study nanocomposite piezoresistivity. The current work aims at exploring the effect of nanoscale interfacial damage and local matrix damage on the effective properties of the nanocomposites. The interfacial damage in CNT-polymer nanocomposites is modeled through electromechanical cohesive zones and the local polymer matrix damage is modeled through continuum damage mechanics modeling. The effect of each of these damage mechanisms is studied independently under monotonic and cyclic loading conditions to differentiate between the different damage evolution paths and to explore the evolution of associated effective electrostatic and piezoresistive response.