Numerical Investigation of Buckling-Driven Mechanisms for Shape Morphing of Composite Wings

Abstract

Shape morphing has been considered a future direction in the pursuit of maximised aerodynamic and structural efficiency of an aircraft wing by triggering geometric reconfiguration to adapt to specific design requirements or load environments. Researchers have endeavoured to seek for morphing solutions that are simple, predictable, tailorable and with promising shape adjustment. Instead of the traditional structural design against buckling failure, a novel concept now embraces this built-in instability by utilising the nonlinear buckling response of slender elements to produce selective stiffness modification which redistributes the load in the structural system. To enable desired buckling configurations with specific stiffness, three buckling-driven mechanisms are presented in this thesis by restraining the out-of-plane buckling deformation with point, area and maximum displacement constraints. Numerical investigation of the proposed mechanisms is first conducted on a composite plate to analyse the effect on the onset of buckling and postbuckling stiffness modification. The laminate with buckling-oriented mechanisms implemented is then integrated into a thin-walled rectangular composite wing box as a shear web to evaluate its functionality in a structural system. The proposed mechanisms offer effective control of the configurations and augmentation on the attainable range of shear centre relocation and torsional stiffness variation of the wing box. To explore the feasibility in morphing application, the interaction between buckling-induced twist and the aerodynamic load distribution is studied with a simplified aeroelastic wing model. Served as proof of concept, the work of the thesis demonstrates the potential to realise complicated morphing tasks through employing precisely-controlled buckling behaviours in structural components.