Dynamic Compression of Glass/Epoxy Composites: The Effects of Fibre Architecture & Ageing, and Use of Energy Flux as a Characterisation Tool

Abstract

Fibre-reinforced composites (FRPs) are strong, light and corrosion resistant. From marine to aerospace and space applications, potential benefits from wider use of high-strength FRPs include increased fuel efficiency and service life. However, they are also highly complex, with strongly anisotropic properties which depend not just on their constituents but also their meso- and micro-structural properties like fibre architecture and fibre-matrix bonding. Developing a more robust understanding of how they behave is therefore critical if we hope to use FRPs more. High-strain-rate loading conditions are of particular importance for composites, as their high specific strength makes them ideal for many applications involving rapid accelerations, which are often at risk of high-speed impact threats. Here, FRPs with similar fibre and matrix components, but differing fibre architectures, have been studied at loading rates of the order of 0.01/s and 1000/s under both ‘pristine’ condition and after ageing by full saturation in a demineralised water bath at 40 °C. Experiments were designed to ensure equilibrium is reached early in the deformation process to discern information about stiffness and toughness, and the use of energy flux is considered in terms of power and total work done to characterise both experimental conditions and material response.