Parametric Flutter Analysis of Camber Morphing Wing Using Beam-Plate Coupled Model

With the development of intelligent materials (including composite material, metamaterial, etc.), advanced actuators (including shape memory alloy, piezoelectric stack, etc.) and other disciplines, the morphing wing can adjust the geometry of the wing adaptively through flexible deformation to ensure the highest aerodynamic efficiency. However, flexible and light wings are prone to induce a structural response by aerodynamic loads, leading to instabilities such as flutter. The main structural modelling approach for conventional flutter problems is to use beam elements or plate elements, which have different accuracy in dealing with different aspect ratios of the wings. Camber morphing wing is mainly composed of the leading edge segment which can’t deform and only provides support and the morphing segment which deforms under the drive of actuator. The leading edge is usually treated as a rigid body and only the deformation of the flexible trailing edge is considered in the aeroelastic analysis of the camber morphing wing. For a camber morphing wing with an aspect ratio above 5, the aerodynamic deformation of leading edge structure cannot be ignored due to its large aspect ratio. Since the beam model has two degrees of freedom of deflection and torsion, and the wing deflection is linearly distributed in the chord direction, the beam model will ignore the deformation of the wing in the morphing segment under aerodynamic load, resulting in deviation in the flutter prediction. However, when the high aspect ratio wings are modelled by a rigid-flexible coupled plate model, the flutter prediction is biased due to the limitations of the plate model. For this particular structure, this paper proposes a kind of structure model based on MSC Nastran, which models the leading edge segment using beam elements with relatively large stiffness and the morphing segment using plate elements with small stiffness and combines both parts with rigid bars. The influences of the proportion of the morphing segment, the connection stiffness between the wing and fuselage, and the degree of freedom of fuselage on the flutter characteristics of camber morphing wing are further studied. This will provide a reference for the design of morphing aircraft using passive/active camber morphing wing.