Flutter Characteristics of Laminated Composite Plates Subjected to Yawed Supersonic Flow Using Inverse Hyperbolic Shear Deformation Theory

This paper deals with the investigations of supersonic flutter characteristics of laminated composite plates. The composite plates are modelled using a recently developed nonpolynomial shear deformation theory, which considers the required shear deformation effects in terms of an inverse hyperbolic function of thickness coordinate. The aerodynamic load is calculated by implementing linear piston theory including the influence of yaw angle. An isoparametric generalized finite-element formulation is developed for the aeroelastic analysis taking into account of required structural equations such as constitutive relations, kinematics relations, displacement field, and the principle of minimum potential energy together with the supersonic aerodynamics based on linear piston theory. The results are obtained by solving the developed system of governing equations for the flutter boundary, and the obtained results are validated against the existing analytical and numerical solutions. It is concluded that the developed formulation is accurate and efficient for the investigation of flutter behavior of laminated composite plates. Moreover, the strength and stiffness properties of composite plates are greatly influenced by fiber orientation, stacking sequence and material orthotropic ratio, flow characteristics are dependent on the flow angle, and geometric conditions mainly depend upon the boundary conditions. The influences of these stiffness characteristics (fiber orientation, stacking sequence, and material orthotropic ratio), geometric characteristics, and flow characteristics on the flutter boundary are examined and various benchmark conclusions are made. It is concluded that stiffness, flow, and geometric parameters must be considered as essential design parameters for enhanced flutter speed of supersonic vehicles fabricated of composite materials.