Requirements on high efficiency of rotating machinery forces engineers to deal with problems of self-induced vi brations and balancing of rotors in a serious and scientific manner. The last decade has shown a leap towards the solution of advanced problems of this kind as indicated by the large amount of scientific and engineering papers on rotor dynamics published in international journals. In appreciation of this situation the General Assembly of the International Union of Theoretical and Applied Mecha nics (IUTAM) at its meeting in Moscow in 1972, acting on a proposal by the Danish Adhering Organization, decided to sponsor an international symposium on the "Dynamics of Rotors" . The scientific planning of the symposium was handed by a scientific committee, consisting of Prof. R.E.D. BISHOP, UK, Prof. S.H. CRANDALL, USA, Prof. F.M. DIMENTBERG, USSR, Dr. A. TONDL, CSSR, Prof. H. ZIEGLER, Switzerland and Prof. F.I. NIORDSON, Denmark, (Chairman). This committee was charged with the selection and invitation of a small number of outstanding scientists in the field, whose contributions to the symposium are presented in this volume. Participation was restricted to invited scientists and there were 87 active participants from 18 countries. Apart from a financial contribution from IUTAM to sup port travel and subsistence of invited participants, generous contributions were received from the following Danish Companies: Burmeister & Wain, Danfoss, The Danish Sugar corporation, DISA, Elsinore Shipbuilding Engineer, Kyndby v~rket, Niro Atomizer, and the Swedish Company STAL-LAVAL. The contributions are gratefully acknowledged.

Inhalt
Recent Developments in Multiplane-Multispeed Balancing of Flexible Rotors in the United States.- Dynamic Properties of Turboset Rotors.- Lateral Stability and Vibrations of High Speed Centrifugal Pump Rotors.- On the Numerical Investigation of Nonlinear Periodic Rotor Vibrations.- The Vibration and Stability of Laterally Flexible Shafts Driven and Supported by Hooke's Joints.- Self-Excited Vibrations of Rotors.- Helicopter Ground Resonance A Simplified Approach.- Vibration and Its Control in Rotating Systems.- Divergence and Flutter Boundaries of Systems under Combined Conservative and Gyroscopic Forces.- Limits to Modal Balancing of Flexible Rotors.- The Effect of Support Flexibility on the Stability of Rotors Mounted in Plain Cylindrical Journal Bearings.- Rotating Blade Analysis by the Finite Element Method.- Response Characteristics of a Rotor with Flexible, Damped Supports.- The Derivation of Bearing Characteristics by Means of Transient Excitation Applied Directly to a Rotating Shaft.- Nonlinear Excited and Self-Excited Precessional Vibrations of Symmetrical Rotors.- The Balancing of Flexible Rotors.- Some Recent Computer Studies on the Stability of Rotors in Fluid-Film Bearings.- Stabilization of Self-Excited Rotor Vibrations by an Active Damper.- New Field Balancing Method on Tandem Connected Multispan Flexible Rotor System.- The Dynamics of Synchronous Whirl in Turbine Rotors.- On the Stability of Periodic Systems in Connection with Rotating Shafts.