Finite element analysis of transverse cracking behaviour in hybrid angle-ply composite laminates

The authors previously presented a 3D finite element method for calculating strain energy release rate and stiffness reduction in transversely cracked cross-ply hybrid laminates. The procedure is based on the computation of strain energy in the laminates with simulated crack and their incremental extensions for applied strains. In the present paper 3D FE method is further extended to study the crack behaviour in hybrid angle-ply laminates under constant applied strain. Variations of strain energy release rate and stiffness reduction with fibre orientation angle θ of outer GR/E layers for different GR/E-GL/E hybrid angle-ply laminates have been calculated. The effects of different geometrical parameters on the crack extension behaviour in width direction have been studied. Variation of strain energy release rate and stiffness reduction in cracked hybrid angle-ply laminates depend not only on the fibre orientation angle θ of the outer GE/E layers but also on the material properties and number of cracked and uncracked layers in the laminate.