Simulation Investigations of the Effect of a Supporting Structure Defect on the Dynamic State of the Rotor Supported on Slide Bearings

Abstract

The present article reports an attempt to assess the effect of the defect having the form of supporting structure fracture on the dynamic state of the rotor supported on slide bearings. The investigations were conducted on an experimentally verified numerical model of a selected large-dimension rotating machine. Within the framework of the investigations, selected cases of a defect localised in the region of one of bearing supports were analysed. The applied method of calculations comprised two basic stages. The first stage consisted in determining complex flexibility characteristics of the supporting structure at the rotor foundation place. In the second stage the obtained flexibility characteristics, after transformation to real matrices of stiffness, damping, and apparent masses, were used for determining parameters of rotor motion. As a result of the calculations, characteristics were obtained that provide opportunities for assessing the effects of the examined defects on rotor vibrations within a wide range of rotational speeds.