Development and Verification of Transfer Matrix Unbalance Response Procedure for Three-Level Rotor-Foundation Systems

Abstract

Details are presented of an analysis and computer code for the calculation of complex multi-span rotor-bearing-pedestal-foundation systems. This multi-level system analysis is based on the Prohl-Myklestad transfer matrix method. The rotor model used is similar to that given by Lund and Orcutt [1]. Eight-coefficient bearings are also used, to permit elliptical orbit rotor motions. The bearings are mounted in massive, damped flexible pedestals, which are themselves mounted upon a foundation structure with distributed mass and stiffness properties. The foundation in turn, is supported on a number of flexible-damped supports. Different foundation properties in the horizontal and vertical directions are included. The analysis is described in detail, along with the computer code, and the results obtained with it are compared with data published previously by other investigators. It is shown that transfer matrix methods can be successfully used for multi-level systems, and that the additional computational ejfort involved is moderate. Three applications of the code are described which validate various aspects of the analysis and the computer program.