samcef 转子动力学-11.pdf

SAMCEF for ROTORS Chapter 3.6: Critical speeds analysis This document is the property of SAMTECH S.A. MEF 101-03-6-A, Page 1 Table of contents Chapter 3.6: Critical speeds analysis Introduction Algorithms  Running the analysis  Files  Listing Campbell diagram Complex eigenmodes and energy distribution This document is the property of SAMTECH S.A. MEF 101-03-6-A, Page 2 Introduction Chapter 3.6: Critical speeds analysis The purpose of this analysis is the computation of the critical speeds and the verification of the stability of a I. Introduction structure with rotating parts. II. Algorithms III. Running the analysis The following equation is solved in a non rotating frame: IV. Files V. Listing VI. Campbell diagram Where, VII. Complex eigen modes and • K is the generalized stiffness matrix with the contribution of the structural stiffness, stiffness of the joints, circulatory forces energy distribution • M the mass matrix • B(Ω) is the generalized damping matrix with the contribution of the structural damping, the damping of the joints and the gyroscopic effect • H is the hysteretical damping matrix • q the displacement vectors • Ω is the rotation speed [rad/sec] of the reference rotor. When several rotors are present in the model, the gyroscopic matrices and the circulatory forces matrices are m