Determination of the Eccentricity of a Rotor by Impulse Excitation Technique of Vibration

Abstract

The aim of this paper is the development and validation of an impulse excitation technique to determine static imbalance of a rotor. The experimental measurement of the vibroacustic response is carried out by using a condenser microphone. In determining the center of mass three measurements are needed: one in plane flexure, and other out of the plane flexure, to which is added a measurement for a balanced rotor. By the means of Finite Element Method (FEM), the natural frequencies and shape modes of two rotor specimens are determined. The analysis is carried out in balanced condition as well as unbalanced one, after artificially induced imbalance. The vibration responses of the specimens, in free-free conditions, are carried out using algorithms based on Fast Fourier Transform (FFT). To validate the results of the modal parameters estimated using Finite Element Analysis (FEA) these are compared with experimental ones.