Vibration Isolation in a System Using Granular Medium27

Abstract

The dynamic behavior of vibration systems containing granular media is experimentally investigated using several models. Impact tests are performed on two different types of frame models with and without granular medium. The tests indicate that the systems containing granular medium dampen vibration. This dynamic characteristic is discussed and illustrated using the finite-element approach to calculate the dynamic behavior of the frame model. These dynamic characteristics enable vibration to be isolated in a system with rigid bodies containing granular medium. A rigid vibration-isolation system, mainly constructed from pipes and granular medium, is used to dampen a cylinder excited by electromagnetic force. The level of noise generated from the cylinder is analyzed in relation to the granular medium and the structure of the vibration-isolation system. The noise level is significantly reduced in this system. © 1995, The Japan Society of Mechanical Engineers. All rights reserved.