Reliability Analysis of Composite Laminates with Load Sharing

By viewing a composite lamina as a homogeneous solid whose directional strengths are random variables, lamina reliability under multiaxial stresses may be determined using either an interactive or a noninteractive criterion. From the reliability values for the individual laminae comprising a given laminate, the authors have previously proposed a method for determining bounds for the overall laminate reliability. In this paper, simple physically plausible phenomenological rules arc proposed for redistribution of load after a lamina has failed within the confines of a laminate. These rules arc illustrated by application to [0/±15], and [90/±45/0], graphite/epoxy (GR/EP) laminates and the results are compared to the previously proposed bounds.