Micromechanical modelling of finite deformation of thermoplastic matrix composites

Abstract

The prediction of the constitutive behavior of thermoplastic matrix composites from quasi-static up to impact rates demands a detailed understanding of the behavior of the polymeric constituents of these materials; this is due to the pronounced rate dependence of the polymeric matrix. This paper is an attempt at approaching the prediction of finite deformation of thermoplastic matrix composites, using a multi-scale approach in which the fibre and the matrix are separately modelled and combined within a finite element scheme to determine the constitutive response of the test composite. A micromechanical model comprising a finite element implementation of constitutive laws for the fibre and matrix constituents are discussed. The robust formulation for predicting the behavior of the semicrystalline polymer was successfully developed, including the techniques of generating the 3D representative volume element (RVE) of composites as well as prescribing the periodic boundary conditions on the 3D RVE. Finally, the validation studies for predicting the elastic properties of the composite using the Finite Element (FE) methods and the effect of spatial arrangement of the fibre inclusions within the matrix at finite strains are illustrated