Abstract
The reliability-based optimum laminate construction of a laminated composite plate subject to in-plane loads is addressed by adopting lamination parameters as design variables. The reliability of each ply failure is evaluated by the first order reliability method, where the material properties and applied loads are treated as random variables. The first ply failure criterion is adopted as the plate failure. Then, the system is modeled as a series system consisting of each ply failure. The system reliability is approximated by Ditlevsen's bounds. The lamination parameters have been used as intermediate design variables for deterministic optimization. Because the structural response can be described by a smooth function in terms of the small number of the lamination parameters. In this study, the lamination parameters are applied to the two types of reliability-based optimization. The effectiveness of using the lamination parameters is demonstrated through numerical calculations.
