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 rotorsupport 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 ringsupported 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.

Dynamic analysis of the rotor system with elastic ring squeeze film damper considering oil film temperature

“…where w c is the angular velocity. δ j is the jth ball element's deformation and it can be given as: The squirrel cage force and elastic ring force can be given as [14,[38][39][40][41]:…”

“…As ERSFD is mounted on the combined support, it's necessary to analyze the complex rotor system. Sun et al [14] proposed a variable stiffness rotor model and investigated the complex rotor's dynamic behaviors. Chen et al [15] proposed a novel rotor-bearing-stator coupling model to research the aero-engine's nonlinear phenomena and vibration characteristics.…”

“…Mathematical model of the complex rotor with ERSFD By introducing nonlinear forces of the corresponding nodes, the differential equations of the beam element and the disk are assembled. The rotor substructure's general dynamic equation is expressed as follows[14][15][16][31][32][33][34].…”

Dynamic analysis of the rotor system with elastic ring squeeze film damper considering oil film temperature

“…Mathematical model of the complex rotor with ERSFD By introducing nonlinear forces of the corresponding nodes, the differential equations of the beam element and the disk are assembled. The rotor substructure's general dynamic equation is expressed as follows[14][15][16][31][32][33][34].…”