Abstract: A composite solar powered UAV with a conventional aerodynamic layout of three fuselage structures and a maximum take-off weight of 40 kg was designed. Based on the structure design and aerodynamic performance analysis, the finite element structure model of the UAV is established. The strength, stiffness and stability of the wing, the horizontal stabilizer, the vertical stabilizer and the solar cell module of the UAV are checked based on the finite element analysis. The maximum stress criterion is applied for strength check. It is shown that the strength margin of the outer wing section, inner wing section, horizontal stabilizer, central vertical stabilizer and the outer vertical stabilizer of the UAV are 2.4, 0.48, 2.13, 1.84 and 1.94, respectively, with the load factor of 2.5 and the safety factor of 2.0. In order to improve the stability of the upper skin of the wing, the structure weight of the optimal lay-up scheme is about 12.3% heavier than that of the initial lay-up design scheme. Flexible solar cell panel is bonded on the upper skin of the wing, and its strength check is carried out.

Key words: composite material, UAV, solar power, design, finite element