Transient Analysis of Rotor-Bearing Systems Using Component Mode Synthesis

Abstract

A method of component mode synthesis is utilized to determine the forced response of linear multi-shaft rotor-bearing systems. The formulation allows for simulation of system response due to blade loss, base shock, maneuver loads, and specified fixed frame forces. The motion of each rotating component of the system is described by superposing constraint modes associated with boundary coordinates and constrained precessional modes associated with internal coordinates. The precessional modes are truncated for each component and the reduced component equations are assembled to obtain a set of complex system equations of reduced order. The method allows for nonsymmetric effects and comparative results are presented for various levels of mode truncation for two example cases.