Virtual modelling of microscopic damage in polymer composite materials at high rates of strain

Abstract

This paper reports on the development of a multiscale modelling approach aimed at producing virtual material data for the macroscopic finite element analysis of composite materials and structures subject to high rates of strain, e.g. under blast or ballistic loading. Finite element simulations were undertaken on a microscale unit cell consisting of S2/8552 glass/epoxy fibres and matrix. Simulations were run in tension, compression and shear from very low (1 s⁻¹) to very high (10 000 s⁻¹) strain rates to predict the effective mechanical properties of a mesoscale unidirectional composite yarn. The microscale model predicts the stiffness and strength values for the loading situations in which validation data are available. Not only is strain rate dependence observed in the model, but also key damage modes can be identified, such as fibre failure, interface failure and matrix cracking.