Response in passing through critical speed of arbitrarily distributed flexible rotor system. I - Case without gyroscopic effect. II - Case with gyroscopic effect

• Published in: Bulletin of the JSME 1983-07, Vol.26, p.1198-1212
• Main Author: Nonami, K
• Format: Article
• Language: English
• ISSN: 0021-3764

The response characteristics of flexible rotor systems with arbitrarily distributed mass passing through many critical speeds sequentially are investigated using numerical solutions obtained from the transition matrix method. These approximate equations can be used to estimate the total behaviors of the vibrations of the shaft or the maximum amplitudes not only in passing through a single critical speed but also in passing through many critical speeds. It is shown that the maximum amplitudes in transition through each critical speed are not influenced by the starting point of the accelerations and that they are close to those in the accelerated cases from the state of nonrotation. Next, the gyroscopic effects of an arbitrarily distributed mass rotor were considered. The approximate equations expressing the responses of general shaft systems on isotropic and anisotropic supports passing through the critical speeds were derived using an asymptotic method. The nonstationary vibration of flexible rotors on anisotropic supports in passing through two neighboring critical speeds were calculated and the coupling phenomena were examined. Numerical solutions were obtained for the whirling directions in transient vibrations of a fundamental rotor on anisotropic supports.