FLUTTER SPEED ESTIMATION FOR FOLDING WING SYSTEM

Recently, morphing aircrafts with multiple mission capabilities are developed by several projects such as NASA or Defense Advanced Research Projects Agency. One of the morphing concepts is the folding wing system with out-ofplane motion. It can adjust flight performance from a cruise configuration to a high speed configuration. A typical procedure of aeroelastic analysis, there are several parameters with important roles, such as fold angle and hinge stiffness. According to Ref. [1], the folding structural natural frequency and the flutter velocity are sensitive to the angle and the hinge stiffness. On the other hand, Flutter speed can be controlled by ply angle of a laminated composite plate due to directional dependency of strength and stiffness of a material. In presented work, the structure is modeled by using Finite Element Method (FEM) and the flow is analyzed by Doublet Lattice Method (DLM). Additionally, the PK method is obtained for aeroelastic analysis.