Mechanical Instability

Mechanical Instability

Thomas Krysinski, Consultant
François Malburet, ENSAM, Aix-en-Provence, France

ISBN : 9781848212015

Publication Date : May 2011

Hardcover 368 pp

147.00 USD



This book focuses on the stability of mechanical systems, in other words their free response when they are removed from a position of equilibrium following a temporary disturbance.

After reviewing the main analytical methods available for assessing the dynamic stability of systems, the book provides details on the fundamental difference in nature between the phenomena of forced resonance vibration of mechanical systems subjected to an imposed excitation and instabilities that characterize their free response.

Taking case study examples from the field of aerodynamics and helicopter design in particular, analysis and assessment are provided for instabilities arising from the rotor– structure couplings, the instability of control systems, the self- sustained instabilities associated with the presence of internal damping, and instabilities related to fluid–structure coupling for fixed and rotating structures.

Taking an original approach, and following the analysis of the various instability phenomena, the book provides examples of solutions to these problems obtained using both passive and active methods.


1. Notions of Instability.
2. Rotor–Structure Coupling: Examples of Ground Resonance and Air Resonance.
3. Torsional System: Instability of Close-loop Systems.
4. Self-sustaining Instability for Rotating Shafts.
5. Fluid–Structure Interaction.

About the authors

Tomasz Krysinski, a dynamics specialist, is Head of the vibration and internal noise department at Eurocopter engineering and design department.

Francois Malburet is an Associate Professor at ENSAM, Aix-en- Provence, France.