Transverse Properties Prediction of Polymer Composites at High Strain Rates Based on Unit Cell Model

Abstract

Mechanical properties of the polymer composites are rate-dependent. The representative volume element (RVE) of unidirectional composites considering the rate-dependent effect of polymers is established with the Improved Bodner-Partom model implemented through three different numerical integration methods. Then, to increase stable time increment, the size of the RVE model is increased properly, and to relieve stress oscillation in the model, a mass scale method is adopted. Through applying periodic boundary conditions, one element model and one RVE model with fiber square arrangement are used to verify the accuracy of a constitutive model of the polymer and simulation method of RVE, respectively, with simulation results compared with the experiment results. The corresponding CPU time consumed by the three different integration methods is compared simultaneously. The models with fiber random or regular distribution (square, diamond, and hexagon arrangement) are analyzed to reveal the effects of fiber arrangement on predicted response under high strain rate loading. Effects of void volume fraction on the response predicted from fiber regular arrangement models are presented. A numerical scheme is developed to establish models with fibers and voids random distribution. With Python language, effects of the fiber arrangement on the predicted results and influences of existence of voids with random distribution on composite mechanical properties are revealed using the Monte-Carlo method.