Numerical and Experimental Investigation of Rubbing Existence in the Context of a Rotating Machine Under Base Excitation

Abstract

This work presents a numerical and experimental investigation regarding the dynamic behavior of a rotating machine under base excitation in the case of disc–stator rubbing. In the present study, the rotating machine is composed of a disc mounted on a flexible shaft supported by rolling bearings at the ends of the shaft. The model is obtained from the classical Lagrange’s equations and the finite element method, considering both the strain energy and kinetic energy of the shaft and the kinetic energies of the disc and the unbalance mass. The phenomenon of rubbing was included in the modeling of the base excited rotor. Two different rubbing models were taken into consideration. The numerical results were compared with the experimental ones from a test rig constructed to support the present research work. Different experimental tests were performed both in the frequency and the time domain, so that frequency response functions, orbits, and unbalance responses were obtained. A good correspondence between numerical and experimental results was observed.