Impact of Structural Material Properties on the Aeroelastic Response and Aerodynamic Efficiency of a Wing

Aeroelasticity is essential for evaluating the flexibility of lifting surfaces, as the resulting vertical air velocities can greatly affect an aircraft’s structural integrity. This study investigates the influence of material properties on the aeroelastic twist of a wing. The torsional and bending mode natural frequencies are first identified to determine the flutter speed analytically, using the P–K method and arbitrary motion dynamics via Wagner’s function. In addition to estimating the flutter speed, both pre-and post-flutter behaviors are analyzed. For a rectangular wing, the differential equation of the twist angle—derived by applying strip theory to slender beam theory—is solved to obtain the spanwise aeroelastic twist distribution. Because the wing box considered in this study incorporates spars and stringers, making it extremely stiff, aeroelastic flutter does not occur within the UAV’s flight envelope due to its high effective torsional rigidity. Consequently, numerical flutter analysis, including Fast Fourier Transform (FFT) of the time response, is not performed for this wing configuration. Since the effective torsional rigidity is very high, the twist angles along the half-span are expected to remain small. The findings provide valuable insights into the dynamic aeroelastic behavior and aerodynamic efficiency of a UAV wing.