Numerical and experimental investigation of the vibration of rotors with loose discs

Abstract

In this study, the energy method has been used to develop a finite-element code for studying the effects of loose rotating discs on the rotor—bearing systems’ response. A mathematical model of the loose disc has resulted in terms similar to unbalance and gyroscopic effects in the equation of motion of the system. Results of this study show that rotor response and beating phenomena are a function of measurement location, loose disc mass and inertia, ratio of rotating speed to the speed of loose disc, and clearance between the loose disc and shaft considering constant speed for loose disc and shaft. The developed finite-element model can numerically give the response of rotors with any number of loose discs at any location with isotropic or orthotropic supports. Results of numerical calculation have been verified by experimental tests.