Statistical analysis of the progression of transverse cracking and delamination in cross-ply laminates

The paper presents a statistical analysis of the transverse cracking and delamination process induced in cross-ply laminates subjected to tensile loading. First, the paper considers the initiation and progression of transverse cracking. This progression is evaluated by an iterative procedure combining a generalized model for evaluating the stress field in a cracked laminate with a statistical distribution of strengths in the 90 degrees layer. Comparisons between the results obtained by this procedure and the experimental results of the literature show that for very low crack densities the progression of transverse cracking is governed by a strength distribution associated with weakness areas resulting from the presence of particular defects in laminates. Next, for higher crack densities the strength distribution in the 90 degrees layer can be described by a pseudo-normal distribution associated with the other defects. Finally, the paper considers the development of delamination which is initiated from the crack tips in the case of some laminates. (C) 2000 Elsevier Science Ltd. All rights reserved.