The behavior of cracked cross-ply composite laminates under simple shear loading

Abstract

An interlaminar shear-stress analysis developed earlier (Tsai et al. 1990, Proc. ASME 1990 Winter Annual Meeting, AMD-Vol. 111, MD-Vol. 22, pp. 9–18. ASME, New York) for a [ Φ m θ n ] s bi-directional composite laminate is combined with the Timoshenko beam theory in this work. A cantilever beam of a [ 0 m 90 n ] s cross-ply laminate with a cracked 90° layer is analyzed. Displacements, strains, forces and laminate shear modulus reduction due to matrix cracking in the 90° layer were obtained. The relationship obtained between the shear modulus and transverse crack density is in complete agreement with predictions from a pure shear analysis (Tsai and Daniel 1991, submitted to Int. J. Solids Structures). This proved that simple shear loading can give the correct shear modulus data as pure shear. Experimental results obtained by a simple shear test agree very well with theoretical predictions.