Vibration characteristics of rotor system with coupling misalignment and disc-shaft nonlinear contact

Abstract

Typically, the interference fit is used to perform the tight junction between disc and shaft. Nevertheless, the nonlinear contact between disc-shaft is neglected in tradition research. Hence, aimed at the shortcoming, considering the nonlinear contact between disc-shaft, the finite element model of rotor system featured with coupling parallel misalignment is established based on Timoshenko beam theory. Firstly, due to the nonlinear of disc-shaft contact, Newmark-β method is employed to combine Newton-Raphson method to solve the dynamic response. Then, according to the comparative analysis between dynamic characteristics of rotor systems operated with three conditions, the concretely discussion on the effect of initial interference and parallel misalignment degree are performed. The results show that disc-shaft nonlinear contact can cause the slight collision between disc-shaft, and the existence of parallel misalignment can intensify the slight collision. Besides, as rotation speed up, the contact states between disc-shaft become the process of repeated cycles: separation, contact, and then separation. Finally, the experiment study is conducted, and the concluded that the experiment result is corresponding to the simulation result can be obtained. It is established that the research results can provide possibilities for the identification and diagnosis of the rotor system with disc-shaft nonlinear contact.