Self-excited vibration analysis of spline rotor systems considering parallel and angular misalignments

To address the instability phenomenon of aerospace splines at supercritical speed, the law of self-excited vibration (SEV) phenomenon of rotor systems considering parallel and angular misalignments is systematically investigated. The finite element model (FEM) of a rotor system is developed, incorporating spline internal friction damping. The spline is modeled by a nonlinear time-varying stiffness theory derived from the slicing method and the penalty function method. The parallel and angular misalignments are considered in the nonlinear time-varying stiffness model. The effects of the misalignment on critical speed (CS) and SEV of systems are analyzed. Moreover, the validity of the proposed spline rotor dynamic model is established through a comparison between simulation and experimental results.