Abstract: Unmanned Aerial Vehicle has been one of the important members in the aviation industry. For lightening the weight of UAV structures in the preliminary design phase, composite material is used. Composite material has been widely used in UAV structures because of various of excellent performances, such as strength and stiffness ratio, shakeproof property as well as the performances in the process of manufacturing. Meanwhile, composite laminate has excellent designable property in the process of manufacturing, so it is widely used among all the types of composite materials. In this paper, the wing structure of a certain electromagnetic-launch unmanned aerial vehicle is selected as the research objective, and the finite element model of a composite wing structure is created. Then, the mass of the structure is chosen as the objective function, the displacement of wingtip and the failure index are chosen as constraints, and the composite wing structure is optimized by using the engineer software. The results should meet the demand of strength and stiffness during the optimization. The final optimization results show that the ratio and thickness of plies of the composite material has been redesigned. Compared with the previous designing scheme, the weight of wing structure is obviously reduced after the free-sizing optimization, which could achieve the objective of optimization.

Key words: unmanned aerial vehicle, composite, wing structure, finite element model, free-sizing optimization