This volume contains selected papers presented at the Symposium on "Recent Developments in Non-linear Oscillations of Mechanical Systems", held in Hanoi, Vietnam, from 2 - 5 March 1999. This Symposium was initiated and sponsored by the International Union of Theoretical and Applied Mechanics (lUI AM) and organised in conjunction with Vietnam National University, Hanoi. Ihe purpose of the Symposium was to bring together scientists active in different fields of oscillations with the aim to review the recent progress in theory of oscillations and engineering applications and to outline the prospects in its further achievements to then co-ordinate and direct research in this field to further co-operation between scientists and various scientific institutions. An International Scientific Committee was appointed by the Bureau of IUI AM with the following members: Nguyen Van Dao (Vietnam, Co-Chairman) E.J. Kreuzer (Germany, Co-Chairman) D.H. van Campen (The Netherlands) F.L. Chernousko (Russia) A.H. Nayfeh (U.S.A) Nguyen Xuan Hung (Vietnam) W.O. Schiehlen (Germany) J.M.T. Thompson (U.K) Y. Veda (Japan). This Committee selected the participants to be invited and the papers to be presented at the Symposium. As a result of this procedure, 52 active scientists from 16 countries responded to the invitation, and 42 papers were presented in lecture and poster discussion sessions.

Zusammenfassung
Proceedings of the IUTAM Symposium held in Hanoi, Vietnam from 2-5 March 1999

Inhalt
Stability Improvement of the Impact Dynamical Systems-Analytical and Numerical Methods.- Theoretical and Experimental Evidence of Symmetric Response Instability in the Finite, Planar Dynamics of a Circular Arch.- Dynamical Analysis of an Offshore Platform with Vibration Absorbers.- Complex Dynamics of a Simple Mechanical System: The Parametrically Excited Pendulum.- Control of Oscillations in Systems with Many Degrees of Freedom.- Elimination of Instabilities in Rotors Supported in Gas Bearings.- Integrated Electromechanical Multi-Coordinate Drive with an Elastic Deformable Slide.- Control of Shipboard Cranes.- A Consistent and Effective Method for Nonlinear Random Oscillations of MDOF Systems.- Stability and Hopf Bifurcation of a Four-wheel-steering Vehicle Involving Driver's Delay.- Moored Crane Vessels in Regular Waves.- On the Stability of Systems of Differential Equations Unsolved for Derivatives.- Stability of Controlled Motion of a Gymnast in High-speed Mid Air Maneuvers.- Asymptotic Methods for investigating Non-linear Wave Processes.- Some Problems on Non-linear Oscillations.- Stationary and Transient Processes in Oscillating Systems with Two Degrees of Freedom Subjected to Parametric and Forced Excitations.- On the Application of Two Perturbation Methods to Non-linear Systems.- New Method of Calculating the Vibration of Offshore Structure Subjected to Wave Action.- On the Transverse Vibrations of Beam-Bridges Under the Action of Some Moving Bodies.- Pile Soil System Identification by a Modal Testing Approach.- On Numerical Methods for Constrained Mechanical Systems.- A Technique for Solving Nonlinear Systems Subject to Random Excitation.- On the Identification of Nonlinear Systems.- Reduction Methods for Non-linear Vibrations of Spatially ContinuousSystems with Initial Curvature.- Asymptotic Method for Investigation of m-frequency Oscillation Systems.- Nonlinear Oscillations of Vehicles in Convoy.- Instability Phenomena of Foldable Structures with Unilateral Contact.- Similarities in the Yaw and Roll Dynamics of Ships in Extreme Astern Seas.- Non-linear three-dimensional Oscillations of Fluid Conveying Viscoelastic Tubes with an Additional Mass.- Nonlinear Dynamics of a Rigid Rotor on Compliant Journal Bearings.- Nonlinear Dynamic Behaviour of Shape Memory Alloy Oscillators.- Nonlinear Waves in a Fluid-Filled Planar Duct with a flexible Wall.- Addresses of participants.- List of Sponsors.