Reliability Based Optimization of Composite Laminates for Frequency Constraint

The reliability based optimization (RBO) issue of composite laminates under fundamental frequency constraint is studied. Consid-ering the uncertainties of material properties, the frequency constraint reliability of the structure is evaluated by the combination of re-sponse surface method (RSM) and finite element method. An optimization algorithm is developed based on the mechanism of laminate frequency characteristics, to optimize the laminate in terms of the ply amount and orientation angles. Numerical examples of composite laminates and cylindrical shell illustrate the advantages of the present optimization algorithm on the efficiency and applicability respects. The optimal solutions of RBO are obviously different from the deterministic optimization results, and the necessity of considering mate-rial property uncertainties in the composite structural frequency constraint optimization is revealed.