Aeroelastic Analysis of a Double-Sweep Wing with the Metal/Composite Sections

In this paper, we investigate the aeroelastic behavior of double-sweep metal and symmetric composite layup wings. Various strategies have been proposed to suppuration of instability such as using the composite materials in structure. The wing is considered as a cantilever beam with 3 degrees of freedom of bending/ bending/ torsional. For aerodynamic modeling, the quasi-steady and unsteady flow theory in the time domain is used based on the Wagner function and the process of calculation of the flutter velocity is provided in form of software code. Finally, the effect of the ratio of length of the isotropic on the total length of the wing as well as the swept angle of the composite section on the flutter speed have been investigated. The results show that with increasing the length of ratio of the metal part to the total length up to 0.9, the speed of instability increases and after that position, it decreases. Also, negative sweep angle of the swept part of wing increases the speed of instability than the positive sweep angle of the composite part. The results show the best angle of fiber is 30 degrees in range of negative sweep angle, having the highest speed of instability. Also, studies show that with increasing the negative sweep angle from -90 to 0 degrees at different angles of fiber, the speed of instability decreases till to -20 degrees of sweep angle and, then, increases slightly. With increasing the sweep angle from 0 to 80 degrees at different angles of fiber, the speed of instability decreases.