Reliability Analysis of FRP Laminated Plates With Initial Imperfection

Abstract

In this paper, a probabilistic progressive failure analysis method is applied to estimating the reliability of a simply supported laminated composite plate with an initial imperfection under bi-axial compression load. The initial imperfection and the strength parameters are considered as random variables. Ply-level failure probability is evaluated by the first order reliability method (FORM) together with the Tsai-Wu strength criterion and Tan criterion. Current stresses in the laminated structure are calculated by classical lamination theory with the stiffness being modified based on the last step ply failure. Probabilistieally dominant ply-level failure sequences leading to overall system failure are identified by branch and bound method. The system failure probability is estimated through the union of significant failure sequences. A numerical example is presented to demonstrate the methodology proposed. Parameter studies show that the deviation of the initial imperfection and strength parameters largely influence the system reliability.