Probabilistic Optimum Design of Symmetric Laminates under First-Ply Failure

This paper proposes a procedure for the optimum design of composite laminates with initial imperfection under probabilistic considerations. The initial imperfection, strength parameters and ply-level thickness are considered as random variables. Ply-level failure probability is evaluated by the first order reliability method and system reliability is computed based on the first-ply failure criterion. The optimum design is formulated to consider the laminate thickness as the objective function and reliability requirement as the constraint. A numerical example is presented to demonstrate the methodology proposed.