Optimization Design Of Composite Wing Structure Of UVA

In this paper, the optimization design study of a composite wing structure of an UVA was conducted.First of all, preliminary design the wing for UVA. The beam and rib structure was used in the preliminary design. And composite materials were used in the beam and skin. Then the structure is analyzed by the finite element software MSC.PATRAN&MD.NASTRAN to calculate the strength and deformation under the external force in the given case. The results show that the design meets the strength and stiffness requirements.Finally, the design of structure was tested. It was proved that the method used in the analysis was feasible and effective by the comparative results between the test results and simulation. Nevertheless, it was also proved that the strength of the structure was surplus a lot by the results. So the structure can be further improved.Secondly,the optimization was conducted based on the initial design. The idea of hierarchical optimization was adopted in this paper. The optimization of the entire wing is divided into several levels of layout optimization and size optimization, as well as key components optimization.The first level was wing structural layout optimization, this stage was also consists of two stages, which was topology optimization and size optimization. In the topology stage, a variable density method was used to find the structure layout probably. Then according to the results of the topology optimization, the location of the wing load-bearing element was specific computed by the Simulated Annealing Algorithm (SA).The second level was size optimization. In this stage, the Modified Feasible Direction Method (MMFD) and Sequential Quadratic Programming Method (SQP) were mainly used. Thickness of the main load-bearing element and the skin was the main design variables.The third level was the improvement of the key components of the wing. In this stage, margin of safety law was still used. The optimization of the wing structure was finally completed.The weight of the structure is reduced by4.5%through layout optimization and36%by size optimization while the deformation and maximum stress meets the overall requirements. It validates that the strength, rigidity and stability of the wing which is optimizetd meets the requirements with a lighter weight of the structure. That is this optimization method is feasible and effective.