Dynamics of Asymmetric Rotors using Solid Models

Copyright © 2003 by GTSJ Manuscript Received on July 7, 2003 ABSTRACT Asymmetric rotors or shafts with dissimilar moments of area form a special category of rotor dynamics problems. Of specific interest for these rotors is the instability in the region of half critical speed, also called gravity critical speed. General analysis of such rotors is limited to Jeffcott type beam models. This involves in finding the asymmetry parameter of the shaft DK/K, and use modal properties or simple physical model of a disk on mass-less shaft with asymmetry for a Jeffcott type of analysis. Recent trends in rotor dynamics analysis indicate a shift from beam to solid models, which enable the classical finite element approach to be used in the design process. The rotor geometry is maintained without any simplification to obtain beam models; first CAD model is made, meshed using appropriate elements and perform the rotor dynamics analysis. In this paper, we demonstrate the procedure for rotor dynamics of a solid asymmetric rotor without beam model simplification.