Prediction of the ultimate strength of composite laminates under in-plane loading using a probabilistic approach

A numerical approach to predicting the ultimate strength of composite lamin ates is presented. In order to take into account the wide scatter in ply st rengths, the basic strength distribution functions for the longitudinal, tr ansverse and in-plane shear strengths were obtained using a two-parameter W eibull distribution. These functions, in conjunction with the Tsai-Hill fai lure criterion, were then used to predict the ultimate strength of the comp osites. Reasonable agreement was obtained between the predicted and experim ental results, not only in respect of the ultimate strength, but also in re lation to the stress-strain curves for the various composites.