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The presence of wrinkles in a membrane is the main factor that induces surface errors on space planar film reflectarrays. Based on the commercial finite element (FE) package ABAQUS, a numerical procedure for membrane wrinkle analysis was set up, and used to analyze a square planar film reflect-array under pure shear force to evaluate its induced wrinkle characteristics. First, the effect of shear force on the wrinkle pattern of the array was studied and validated by experiment. Second, the effect of prestress was studied. When the prestress increases, the quantity of the wrinkles increases, and the amplitude of the wrinkles decreases. Third, the influence of the boundary conditions was investigated. A frame side edge structure has a relatively smooth surface, but also relatively high stress. Finally, the behavior of a joint seam was analyzed. The results indicate that a joint band has a significant influence on the wrinkle pattern of the membrane.

Airship shape is crucial to the design of stratosphere airships. In this paper, multidisciplinary design optimization (MDO) technology is introduced into the design of airship shape. We devise a composite objective function, based on this technology, which takes account of various factors which influence airship performance, including aerodynamics, structures, energy and weight to determine the optimal airship shape. A shape generation algorithm is proposed and appropriate mathematical models are constructed. Simulation results show that the optimized shape gives an improvement in the value of the composite objective function compared with a reference shape.