Numerical flutter analysis of composite wing structure on an unmanned aerial vehicle (UAV).

Wings on medium-altitude long-endurance (MALE) unmanned aerial vehicles (UAV) are lightweight with high aspect ratios and highly flexible. They may undergo large deformation. However, this can be improved using composite materials where the stiffness-to-weight ratio and structural stiffness of composite materials can be modified to optimize the flight envelope without compromising the aircraft's weight. Nevertheless, modern UAV design has brought new challenges for structural engineers. The increasing use of light and slender wings leads to structural configurations featuring low natural frequencies, which can easily experience aeroelastic instability. The most important aeroelastic phenomenon is flutter. Flutter is a dynamic instability of a flexible structure associated with the interaction of aerodynamic, elastic, and inertial forces and might cause potentially catastrophic failure. The main objective of this study is to identify the flutter boundary of the composite wing structure. An efficient computation approach and a detailed representation of the wing structural model are required to evaluate the wing structure's dynamic behavior accurately. The aeroelastic and structural analyses of the wing model are performed using MSC. Nastran/Patran. Following the results of the flutter analysis, the wing's structure can be stated that it is safe from the flutter phenomenon. Even though the flutter speed could not be found, the numerical analysis has been carried out exceeded the designed operational range, and there is no indication that the flutter would happen below two times the maximum diving speed. [ABSTRACT FROM AUTHOR]