Dynamic Analysis of the Variable Stiffness Support Rotor System With Elastic Rings

Abstract Elastic rings are common rotor supporting structure, which have been widely used in aeroengine rotor-support system. However, large inertia force and gyroscopic moment may occur during the operation of aeroengine, which may lead to contact between elastic ring and bearing pedestal, and then introduce variable stiffness into the rotor-support system. In this paper, a mathematical model of variable stiffness of elastic ring is proposed and this model is subsequently verified by comparison with simulation analysis and experimental results. Based on this model, a variable stiffness model of an elastic ring-supported rotor is developed by coupling the kinetic equations of the rotor with the deformation of the combined support. Then, the spectrum cascades are used to analyze the dynamic characteristics of the rotor system. In addition, the influences of the variable stiffness of elastic ring on the critical speed of the system are also examined. Finally, some simulation results are verified by experiments on a combined test bench of an elastic ring-supported rotor.