Investigation of Failure Behaviour of a Glass-Fibre Reinforced Thermoplastic Composite

Abstract

This work focuses on the fibre dominated failure of the woven thermoplastic fibre-reinforced composite. The novel experimental methodology induced failures in different deformation modes for the Glass Fibre Reinforced Polypropylene (GFRP) composite studied. Hence the path dependency effect on the failure of this material system can be studied experimentally through the three-dimensional (3D) Digital Image Correlation (DIC) system. A novel failure metric based on the strains experienced by the fibre bundles is developed. From the experimental results, this failure metric is found to be able to eliminate path dependency effect and is independent of fibre orientations. In Finite Element Analysis (FEA), this failure metric is incorporated with the simulations as a virtual tool to predict failures of the GFRP material. From the experimental results, failure envelopes with the failure metric based on the principal strain and fibre strain are developed respectively. Both failure envelopes are implemented in the FEA simulation. The simulations incorporated with the failure metric in principal strain cannot accurately predict failure for the GFRP material system. The simulations incorporated with the failure metric in fibre strain, on the contrary, are found to be able to provide predictions that have a better agreement with the experimental results.