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 s train energy in the laminates with simulated crack and their incremental ex tensions for applied strains. In the present paper 3D FE method is further extended to study the crack behaviour in hybrid angle-ply laminates under c onstant applied strain. Variations of strain energy release rate and stiffn ess reduction with fibre orientation angle theta of outer GR/E layers for d ifferent GR/E-GL/E hybrid angle-ply laminates have been calculated. The eff ects of different geometrical parameters on the crack extension behaviour i n width direction have been studied. Variation of strain energy release rat e and stiffness reduction in cracked hybrid angle-ply laminates depend not only on the fibre orientation angle a of the outer GE/E layers but also on the material properties and number of cracked and uncracked layers in the l aminate.