《Static analysis of a passive vibration isolator with》.pdfVIP

ARTICLE IN PRESS JOURNAL OF SOUND AND VIBRATION Journal of Sound and Vibration 301 (2007) 678–689 /locate/jsvi Static analysis of a passive vibration isolator with quasi-zero-stiffness characteristic A. Carrella, M.J. Brennan, T.P. Waters Institute of Sound and Vibration Research, University of Southampton, Southampton, Hampshire SO17 1BJ, UK Received 7 April 2006; received in revised form 17 October 2006; accepted 18 October 2006 Available online 8 December 2006 Abstract The frequency range over which a linear passive vibration isolator is effective, is often limited by the mount stiffness required to support a static load. This can be improved upon by employing nonlinear mounts incorporating negative stiffness elements configured in such a way that the dynamic stiffness is much less than the static stiffness. Such nonlinear mounts are used widely in practice, but rigorous analysis, and hence a clear understanding of their behaviour is not readily available in the literature. In this paper, a simple system comprising a vertical spring acting in parallel with two oblique springs is studied. It is shown that there is a unique relationship between the geometry and the stiffness of the springs that yields a system with zero dynamic