Damage mechanics analysis of transverse cracks in composite laminates

Damage mechanics is applied to the prediction of transverse cracking in composite laminates. The analysis is performed by assuming that the average crack opening displacement of a transverse crack can be approximated by that in an infinite homogeneous transversely isotropic medium. The analysis elucidates the thermomechanical properties of the laminates with transverse cracks and gives the energy release rate associated with transverse cracking. By assuming that a transverse crack occurs when the energy release rate reaches a critical value and by incorporating the thermal residual stresses arising from the mismatch of thermal expansion coefficients between plies, the transverse crack density is predicted as a function of the laminate stress. The prediction is compared with the experimental results of CFRP cross-ply (0/90m/0) (m = 4, 8 and 12) laminates. An advantage of the present analysis is that it can be applied to an arbitrary laminate.