Nonlinear vibration phenomenon of maneuvering spacecraft with flexible jointed appendages

A nonlinear analytical model for a spacecraft with flexible jointed appendages is presented and subsequently used to investigate the nonlinear vibration phenomenon of the system caused by the joints nonlinearities during the spacecraft maneuvering. In this model, the joint transmitted characteristics which included linear and nonlinear stiffness, damping and friction are introduced into the system by applying the equilibrium conditions between the beams and the joints. Consequently, an explicit set of reduced-order nonlinear ordinary differential equations (ODEs) of motion for the flexible spacecraft with nonlinear joints are obtained based on the global mode method. Through the nonlinear ODEs obtained in this model, the dynamic responses of the system with various joint parameters are worked out numerically for the cases of attitude maneuver and orbit maneuver, respectively. For the case of attitude maneuver, the simulation results show that the damping and friction in the joints have a great influence on the vibration response of the system, especially the residual vibration. For the case of orbit maneuver, some nonlinear behaviors caused by the nonlinear joints are observed such as hardening, jump, sub-harmonic and super-harmonic resonance. More importantly, due to the cubic stiffness of the joint, modal coupling is exhibited, which result in the interaction between translation and rotation of the central rigid body.