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 degrees 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 degrees 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 Dyneeman 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 degrees 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. (C) 2015 Elsevier Ltd. All rights reserved.