LAUSR

Abstract Due to the existence of large number of design variables for large-scale composite laminated structures, such as ply thicknesses and stacking sequence, etc., it has become one of most important concerns to build an efficient optimization design method for composites. In this paper, the purpose is to propose a novel reliability-based two-level optimization design method including thickness and stacking sequence optimizations, where uncertain parameters of composites are taken into account for reliability evaluation. Firstly, by characterizing existing uncertain parameters of composites as random or interval variables, one can carry out uncertainty analysis for structural responses. Then the evaluation models of probabilistic and non-probabilistic reliabilities are separately introduced when treating uncertainties as random and interval variables. Furthermore, by combining the reliabilities with the two-level optimization model, a novel reliability-based two-level optimization model is advanced and the detailed optimization procedures are listed for convenience of understanding. Lastly, two numerical examples including a simple-supported composite plate and a composite wingtip of aerospace plane are given out to demonstrate the validity and availability of the proposed method. The results show that the proposed method can be successfully and efficiently applied in the optimization design of composite structures.