Study on the structure design of solar powerd UAV

High-altitude and long-endurance solar-powered UAV mostly uses the high-aspect-ratio wing. The tip of the wing is very deformed and the flutter velocity is low, which is easily affected by the gust load. The structural safety of UAV flying in the sky is a popular and difficult issue, but there is no design criterion for the structural design of the solar powered UAV. Therefore, in this paper, according to the structural characteristics of large aspect ratio solar powered UAV, the design criteria of structural safety are put forward, and the structure of solar powered UAV is studied respectively from static strength, stiffness and dynamic load. Numerical results show that under cruising condition, the maximum stress of solar powered UAV structure is much lower than the breaking strength of the material, but the sustained vibration caused by the flutter will cause a large overload, which will lead to fatigue and impact damage to the structure. Under the gust response, the structure response converges quickly, but after exceeding a certain flight speed, any gust will cause the structure to diverge and the structure to break down rapidly. At the same time, it can also be seen that the bending, twisting and horizontal waving of the large aspect ratio wing lead to structural flutter destruction.