Torsional Vibration and Related Coupled Vibration

Abstract

Torsional vibrations are often problematic in transient responses when a rotor-bearing system starts up. The vibration is more predominant and unavoidable in geared rotor systems. Though torsional vibration poses long-term problems, new methods of rotor design have been established by employing the transfer matrix method, which are capable of calculating precisely the rotor vibrations according to the shaft configuration. However, several coupled vibration problems have arisen as rotors have become lighter and faster. This chapter reviews conventional technologies including analysis and measurement of torsional vibration. It also explains the latest topics on coupled torsional vibration between a shaft and blade and another coupling effect between torsional and bending shaft vibrations.