The rigid-flexible coupling vibration of assembled disk-composite conical shell structure of electric aircraft in hygrothermal circumstance

Abstract

A novel theoretical formulation for addressing the coupling vibration of the rigid disc and flexible composite conical shell structure (RDFCCSs) in hygrothermal circumstances is established to investigate the vibration evolution of the rigid-flexible composite thin-walled coupled structure of new energy electric aircraft. According to Donnell's thin shell theory, the potential energy of the composite conical shell under hygrothermal load is calculated. A uniform mass model and a set of artificial springs distributed on the interface of the shell and disk are imported to simulate the RDFCCSs. The governing equation of the RDFCCSs with arbitrary foundations in hygrothermal circumstances is deduced according to the Rayleigh-Ritz variational procedure. Systematic experiments and finite element simulations have been demonstrated to confirm the accuracy of the proposed method. Three new rigid-flexible coupling vibration modes of the RDFCCSs that differ from the traditional single thin-walled conical shell element due to the influence of the disk have been revealed. After that, the unique vibration characteristics of RDFCCSs under various masses, axial loads, hygrothermal environments and interface connection stiffnesses are discussed in detail.