Nonlinear Vibrations of Flexible Spacecraft Jointed Composite Appendages: Theory and Experiment

Modern spacecraft often carry flexible multipanel composite structures to meet diverse on-orbit demands. Flexible composite solar arrays consist of multiple honeycomb sandwich panels and flexible hinges, and the nonlinear behavior of the hinges cannot be neglected. In this paper, a novel analytical dynamic modeling method for honeycomb sandwich multipanel solar arrays is proposed, and the rigid–flexible coupling nonlinear characteristics of the spacecraft are investigated. Carbon fiber honeycomb sandwich panels are modeled as anisotropic laminated plates. Lagrange multipliers are introduced to describe constraints at flexible hinges with nonlinear characteristics. A low-dimensional, high-precision nonlinear dynamic model of a flexible spacecraft is developed using the global mode method. A finite element model of the system is also established. The rigid–flexible coupling natural characteristics and complex nonlinear responses of the spacecraft are obtained. Finally, an air-floating platform equipped with a composite honeycomb multipanel structure is designed, and experimental studies, including modal tests and forced vibration tests, are conducted to verify the effectiveness and accuracy of the proposed method. The results show that the flexibility of the composite structures and the characteristics of the nonlinear hinges strongly influence the dynamic behavior of the entire system.