Experimental investigation of a vibration isolation system using negative stiffness structure

The aim of this paper is to propose a vibration isolation system using negative stiffness structure for isolating low frequency vibrations. In this paper, the dynamic stiffness characteristic of the system will be presented clearly. The relationship between the configurative parameters and the stiffness of the elastic element, for which the dimensionless dynamic stiffness of the proposed system is in range from zero to one, will be obtained. Then, an experimental apparatus is configured to examine the characteristic of the vibration transmissibility of the system according to various values of the configurative parameters. Next, the time responses to the multi frequency and random base excitations are also investigated. Besides, the isolation response of the system with negative stiffness structure and the system without negative stiffness structure is considered. The experimental results show that the proposed system has wide frequency range of isolation, especially the resonance phenomenon doesn´t almost occur. Finally, some conclusions are presented.