Parameterized Fictitious Mode of Morphing Wing with Bilinear Hinge Stiffness

Abstract

As a typical morphing wing, a folding wing with structural nonlinearities may encounter complex nonlinear aeroelastic effects during the in-flight morphing process. This paper presents a novel parameterized modeling methodology for efficient modal and nonlinear aeroelastic analysis of a folding wing with bilinear hinge stiffness and the variation of the folding angle. The most attractive feature of the present modeling methodology is that the nonlinear structural dynamics of the folding wing at different folding angles can be efficiently represented via a parameterized fictitious mode. To demonstrate the accuracy of the present method in representing the nonlinear dynamics of the morphing wing, a folding wing with bilinear stiffness in both fuselage–inboard and inboard–outboard hinges was selected as a numerical example. The nonlinear dynamic model of the selected example can be divided into nine subsystems according to different combinations of fuselage–inboard and inboard–outboard hinge stiffness. This paper focuses on the efficient investigation of structural modes, flutter stability, and nonlinear aeroelastic behaviors of the folding wing at the complete morphing parameter space. Besides, the numerical results computed via the present parameterized fictitious mode method were also compared with the direct commercial software. The comparison shows that the nonlinear dynamics of the morphing wing with bilinear hinge stiffness can be investigated efficiently via the present parameterized modeling method.