Probabilistic Failure Analysis for Composite Laminates

Considering the increasing applications of composites as structural components, the reliability of these materials is an important issue. Given the inherent variability of the material properties of composites, a probabilistic approach to the design of these materials is required. In this paper, the first-order second-moment method, coupled with the Tsai-Wu interactive failure criterion, is used to determine the reliability of composite laminates under various plane stress conditions. Uncertainty in material and loading parameters are considered. The method considered requires only the first two moments of the basic variables as input. This factor, along with its ease of use, makes this technique attractive to designers. Numerical examples, along with plots of the effect of coefficient of variation on the safety index, are given for a typical glass/epoxy composite.