Strength Analysis and Accidents of Shaft Destruction under Nonlinear Vibration with Large Unbalance of Turbogenerator Rotor Systems

摘要

This paper employs a new transfer matrix-time marching approach to analyze the dynamic stress of the shaft and the dynamic force at the bearing pedestal while nonlinear vibration with large unbalance was observed on 200MW turbogenerators made in China. According to the calculation results, the mechanism of shaft destruction caused by nonlinear force has been investigated, and some key problems related with the catastrophic failures in several large capacity units are explored. Through this study, the reason and the detail course of the shaft fracture of these units accidents are obtained, and a theory basis of calculating nonlinear vibration of real units are provided.