5R11. Linear and Nonlinear Rotordynamics: A Modern Treatment with Applications. - T Yamamoto and Y Ishida (Nagoya Univ, Nagoya, Japan). Wiley, New York. 2001. 325 pp. ISBN 0-471-18175-7. $94.95.

Reviewed by RG Kirk (Dept of Mech Eng, Rotor Dyn Lab, Virginia Tech, Randolph Hall - Room 119, Blacksburg VA 24061).

The authors have documented in this text their extensive works and accomplishments in this important field of engineering. The background of the authors original works are explained in the Foreword written by Professor Harold Nelson, a well known and respected researcher in the same field of study and well versed in the total history of rotating machinery analysis.

The first half of the text documents, in part, the important early works of Yamamoto concerning the treatment of gyroscopic moments, disk skew, free and forced vibration of continuous, and asymmetrical rotor systems. Their treatment of nonlinear vibrations adds the newer areas of research and analysis by Ishida. Included are discussions of chaotic vibration, harmonic resonance, and cracked rotor vibration. The collected works of both authors cover more than a half-century of research into the dynamics and stability of rotating machinery.

The last half of the text discusses many additional topics necessary for a modern and more complete coverage of rotating machinery analysis. Internal damping mechanisms and non-stationary vibrations for passage through critical speeds are discussed in detail. Other related topics include ball bearings, bearing pedestals, universal joints, oil bearings, annular seals, gas labyrinth seals, tip clearance excitation, and liquid filled hollow rotors. Some of these topics are not covered in great detail, but refer to the work of other researchers in this field of study.

The authors present a summary of the finite element method and relate their derivations to the similar work of Nelson. The comparison of their proposed classic solution method using second-order equations to that of Nelson, who used a solution based on coupled first-order equations, is very instructive. Results are presented for the natural frequency of a uniform shaft on simple supports. Also presented are the results for a single disk including gyroscopics, mounted off mid-span on a slender shaft. These results will be of use to researchers developing their own computer analysis capabilities for such calculations.

The authors are to be commended for including a chapter on the transfer matrix solution method. This solution method can and has been made very efficient for extensive analysis of modern turbomachinery. The formulation presented by the authors for the computation of forced response to imbalance can be extended to the computation of dynamic stability. The final chapter briefly covers measurement and signal processing of vibration signals. The coverage is very limited on this topic, but does prompt the reader to be aware of the problems with FFT analysis, such as leakage error.

The text has been carefully written and includes analytical documentation of several interesting nonlinear effects. The authors present the material mainly from the theoretical viewpoint; the text would be of great value for graduate students or other researchers needing to more fully understand dynamic analysis of rotating machinery. The purpose in writing this text, as stated in the Preface, was to add to the documentation of analytical methods for the study of rotordynamics. The authors have satisfied their purpose. Linear and Nonlinear Rotordynamics: A Modern Treatment with Applications is a welcome addition to current reference texts now available in the area of rotordynamics.