Tensile strength of fibrous composites at elevated temperature

Abstract

This paper describes an analysing methodology to simulate the tensile strength of a unidirectional fibrous composite under thermomechanical loads using properties of constituent fibre and matrix materials and fibre volume fraction only. The stress states in the constituent phases at every mechanical load level are explicitly determined by making use of a bridging matrix, whereas the thermal stresses in the constituents are obtained based on Schepery's formulae. A composite failure is assumed when any constituent material attains its ultimate stress state. The maximum normal stress theory of isotropic materials is used to detect the constituent failure. A unidirectional alumina fibre reinforced aluminium matrix composite at a number of temperatures from room temperature to 773 K subjected to off axial loads has been analysed. The predicted off axial strengths are comparable with the experiments of Mutsuda and Matsuura.