An analytical model to predict residual thermal stress in 2D orthogonal plain weave fabric composites

This paper seeks to address a practical rectangular truss model to predict residual thermal stress in a 2 D plain weave fabric (PWF) composite. The two orthogonal yarns in a micromechanical unit cell are idealized as straight rods subjected to tensile or compression loading resulting in extension or shortening deformation. The residual thermal stresses and equivalent thermal expansion coefficients in a PWF layer are derived from the thermal constitutive equations and the deformation compatibility condition. Based on the deformation compatibility equations, the thermal constitutive relationships for PWF composites are obtained to derive the residual thermal stresses between PWF plies and pure resin. In order to validate the model, experiments have been performed to investigate the mechanical properties of two-dimensional (2D) orthogonal EW220/5284 PWF composites fabricated by resin transfer moulding (RTM). It is shown that the experimental results correlate well with predictions from the new model.