Mechanical properties and energy absorption capability of woven fabric composites under ±45° off-axis tension

Fibre-reinforced polymer composites are generally known for their brittle failure behaviour. Ductility of composites, in contrast, which may be of relevance for specific applications like for energy-absorbing structures, can typically be obtained under ±45° off-axis tension using the in-plane shear effect. In order to provide an extensive database for the in-plane shear behaviour, a comprehensive experimental study of woven fabric composites under quasi-static and high strain-rate ±45° off-axis tensile loading is presented, assessing the non-linear stress-strain behaviour and weight-specific energy absorption capability under different loading rates. The test campaign aims at characterising the influence of fibre material (carbon, glass, aramid, Vectran® and Dyneema®), matrix material (untoughened epoxy resin, toughened epoxy resin and thermoplastic PEEK), weave pattern (plain weave, twill weave, satin weave and braid) and fibre areal weight on the ±45° off-axis tensile mechanical properties. The results reveal failure strain values of up to 28% and significant strain rate effects, influencing stiffness, strength, strain-to-failure and energy absorption.