Overall Properties of Polymer Matrix Composites at High Temperatures: Modeling and Application to the Lightning Strike Problem

Abstract

In this work, a micromechanics-based model for determining high-temperature thermophysical properties of carbon fiber reinforced polymer (CFRP) composites undergoing pyrolysis is presented. The model accounts for the mass loss and material phase changes. Material phase changes include emergence of the secondary char and gas phases in the polymer matrix. First-order Arrhenius kinetics is used to model polymer pyrolysis. The model also accounts for the temperatureand heating rate-dependent volume fractions of the polymer, char, and pyrolysis gas phases. Temperature- and heating rate-dependent representative volume elements (RVEs) of evolving microstructures were generated and numerical homogenization was performed to determine overall thermophysical properties of the CFRP composites. The micromechanics-based models were embedded into the finite element analysis (FEA)-based multiphysics modeling of lightning strike damage in CFRP composites. Computational studies were performed to analyze lightning strike induced thermal damage in a CFRP composite.