Regularity of the transverse crack spacing in a damaged laminate

In evaluating elastic constants for a damaged laminate, the assumption is often made that transverse matrix cracks are equally spaced. To investigate the plausibility of this assumption, an analytical expression for the probability density function of the next failure location in a region of the cross-ply laminate bounded by two existing transverse matrix cracks is derived. The derivation employs the method developed by Oh and Finney for modeling the characteristics of the location of failure in conjunction with a shear-lag solution for the stress state in a transversely cracked layer of a multi-ply laminate. In exercising this model, it is found that the assumption of regularly spaced transverse matrix cracks becomes more plausible as the crack density increases (crack spacing decreases).