Response of a three-degree-of-freedom wing with stiffness and aerodynamic nonlinearities at hypersonic speeds

Abstract

In the design of high-speed aircraft particular attention must be given to the effect of stiffness and aerodynamic nonlinearities. Additionally the thermal effects cannot be ignored since the harsh thermal environment influences the dynamic behaviour of a structure. In the current paper the aeroelastic response of a three-degree-of-freedom wing with a control surface, and stiffness and aerodynamic nonlinearities has been analysed. The nonlinear unsteady aerodynamic forces applied to the model are calculated using third-order piston theory and piecewise linear, and cubic stiffening nonlinearities are implemented in the control surface. The effect of temperature on the model is determined by a steady-state analysis with a predefined temperature distribution. The onset of limit cycle oscillations and the bifurcation behaviours is compared for the different nonlinearities. The effect of initial conditions is determined to quantify their impact on the limit cycle behaviour. This article extends the nonlinear analysis of the aeroelastic response of a wing at hypersonic speeds with an added control surface degree of freedom, with the effect of nonlinear aerodynamics and stiffness included in the model. The results show that different nonlinearities influence the response of the system uniquely and heat plays an important role in the order of excited harmonics.