The rigid-flexible coupling vibration of composite box structure in new energy hydrogen-electricity aircraft with complex circumstance: Theoretical formulation and experiment

This literature contributes to a theoretical formulation to insight into the rigid-flexible coupling vibration of composite laminated box structures (RFCLBs) in new energy hydrogen-electricity aircraft suffering from complex environments. To achieve this target, a creationary mass model distributed on the interface of the thin-walled box structures is utilized to simulate the RFCLBs by the simplified material coefficient matrix. Based on the Rayleigh-Ritz theory, the dynamic equations of RFCLBs in hygrothermal environments are derived. Owing to rigid mass, four novel vibration patterns which are different from traditional thin-walled box structures have been discovered. More specifically for the new vibration models, a series of theoretical and experiment investigations have been carried out to insight the forming and evolution mechanism of RFCLBs by considering the influence of various masses, sizes and hygrothermal environments in detail. The results indicate that the inherent characteristic of RFCLBs is sensitive to the mass of the rigid component. Under varying external excitations, the modal shapes of RFCLBs exhibit randomness contingent upon specific boundary conditions and their respective order. Additionally, temperature exerts a more pronounced effect on frequency than humidity, which might lead to some unpredictable vibration modes.