Application of a Finite Element Package for Modeling Rotating Machinery Vibrations

Abstract

ANSYS has no module to analyze dynamics of rotor-bearing systems,especially to calculate critical speeds. But it has element types, such as beam elementand matrix27 element, which can be modeled as stiffness, damping and mass matrix.In this paper, BEAM4 element and MATRIX27 element are adopted to model theshaft, rotating disks and bearings. Some ideas are presented to deal with critical speedscalculation using ANSYS. The accuracy of the model and the solution technique havebeen demonstrated by comparison with results of previous publications. Very goodagreement has been obtained.

Keywords

• finite element model
• rotor
• bearing system
• critical speeds