of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made.

No abstract

No abstract

A coupled vibrating system (for example turbine-generator set), consisting of a main system (for example shaft system) and a sub-system (for example blade system) which are connected at bonding points (for example the centre boss of a blade), is equivalently reduced to a model suitable for analysis. According to this modelling technique, the eigenvalue analysis of the uncoupled flexible sub-system is done first under the assumption of the fixed bonding point. Then, an equivalent mass-spring system is produced for each eigenmode of the uncoupled subsystem. In this way, the main system plus the additional equivalent mass-spring model of the sub-system is combined into a global system model. This modelling technique is applied to the shaft-blade coupled vibration problems in an actual turbine-generator set and its effectiveness is provided with experimental test results.

The wide application of active magnetic bearing (AMB) requires an aseismic evaluation with respect to AMB rotor vibrations caused by actual earthquakes. A flexible rotor supported by AMB is selected for this purpose. A shaking simulation obtained using the quasi-modal model and the actual Kobe earthquake was completed. A corresponding test rotor was excited by seismic waves and the resulting vibration was measured for the vibration evaluation. In order to reduce the response severity against earthquakes, we propose an additional feed forward control method which is proportional to the signal detected by the accelerometers attached to the bearing housings. Since this additional control can cancel rotor vibration generated by the earthquakes, AMB rotor vibrations are successfully suppressed at a low level.