Improving the performance of a vibration neutraliser by actively removing damping

This paper describes the design of an active vibration neutraliser. The aim of the active element in the neutraliser is to reduce the internal damping of the device and thus make it more effective. Six different control configurations are considered and the input mechanical impedance of each configuration is calculated. This is used to assess the efficacy of each configuration. To study the behaviour of an active neutraliser a beam-like neutraliser is designed and built with piezoceramic patches providing the active element. An analytical model of this device is presented. Simulations and experimental results show that for two control configurations the amplitude of a mass-like structure with the neutraliser attached remains finite at a resonance of the composite system even when damping is entirely removed from the neutraliser, by the control system. (C) 1999 Academic Press.