Failure behaviour in woven thermoplastic composites subjected to various deformation modes

Abstract

Woven thermoplastic composites are attractive to manufacturers due to their thermo-formability, but limitations in predicting complex failure behaviour still hinder widespread use. This work uses new specimen geometries and an associated apparatus to induce a selection of deformation modes and allows composite failure to be investigated under them. These specimens are tested with three different woven composites with varying matrix (polypropylene - PP, polycarbonate - PC), reinforcement (glass, PP), and weave (twill, satin). Strains captured with a Digital Image Correlation (DIC) system integrated with the hemispherical testing device show the strain evolution and deformation mode. Finite Element Analysis (FEA) demonstrates that friction, clamping, and bending have a minor effect on composite failure location and strain state. Experiments show significant differences in macroscale and mesoscale deformation and failure response due to composite constituents and weave architectures. A maximum fibre strain criterion is shown to be effective for fibre-reinforced composites across a range of deformation modes.