Study of the Cross Sections of a Main Wing Spar of a High-altitude Electro-powered UAV

To increase the flight endurance of high-altitude electro-powered unmanned aerial vehicles (UAVs), the main wing with a high aspect ratio should have low structural weight and structural integrity. Because a spar of the main wing with a slender structure and with low structural weight can rupture during flight, developing a light-weight spar for the main wing without sacrificing structural integrity is critical. In this study, cross sections of the spars of the main wing of a UAV were studied to have high stiffness and strength with low structural weight. A finite element analysis was conducted while considering non-linear deformation under bending moments with respect to various cross sections of the spar. The circular section of the spar was determined to have better compressive strength and critical buckling load as compared to the rectangular section of the spar with a similar structural weight.