Robust Optimal Design of Fiber-Reinforced Composite Cylinder with Metallic Liner

An enhanced robust optimal design method dealing with both property and material uncertainties is established in this paper. The method is applied to the robust optimal design of fiber-reinforced composite cylinder with reinforced composite patches and metallic liner subjected to uniform pressure and local loadings. Instead of the traditional numerical approach, modified constraints are used to analytically solve the antioptimization subproblem by a maximizing procedure in the developed method, consequently the computation time for robust optimal design problem can be significantly reduced. The effectiveness and accuracy of the developed method are verified by a degenerated example. Analysis result shows the optimal weight increases significantly with property and material uncertainties as expected. It is also found that the optimal thickness of metallic liner is affected by the utilized design rules of metallic liner. For plastic design, the thickness of metallic liner should be kept as small as possible for a minimal weight optimal design provided that manufacturing and nonleakage constraints can be met. On the contrary the optimal thickness of metallic liner depends on the relative ratio of allowable strain of metallic liner and composite material if elastic design is used.