Lamination Parameters Applied to Reliability-Based In-Plane Strength Design of Composites

This is the authors' abstract. We don't add key points for this paper.

The efficiency of adopting lamination parameters as design variables for the reliability-based optimization of a laminated composite plate subject to in-plane loads is presented. The plate failure is evaluated by the first-ply failure (FPF) criterion, where the ply failure is evaluated based on the Tsai-Wu criterion. According to the FPF criterion, the laminated plate is modeled as a series system consisting of every ply failure. The system reliability of the composite plate is evaluated by Ditlevsen's bounds. Each ply-failure probability is evaluated by the first-order reliability method, where the material properties and applied loads are treated as random variables. As numerical examples, two types of the reliability-based design are formulated in terms of lamination parameters. One is the reliability-maximized design of the constant-thickness plate. The other is the thickness-minimized design under the reliability constraint. Through numerical calculations, it is shown that the reliability has a single peak and a continuous distribution in the lamination parameter space. Consequently, numerical searching rapidly achieves the optimum solution.