The control of structure-borne noise from a viaduct using floating honeycomb panel

Abstract

This paper identifies the method to control the vibration responses of a concrete viaduct models under impulsive force excitation. The frequencies and mode shapes of resonances of the bending vibration across the section can control the magnitude of the structure-borne noise radiation. A plastic hammer is used to excite the cement viaduct model at the centre and at the supporting edge position of the cross-section separately. The results of analysis using a Finite Element Method are confirmed by the experimental findings of the cross-sectional modes. The findings showed that the local modes are of two types: (1) Centre mode - the centre of top panel can move but the edge is fixed. (2) Edge (web) mode - the centre of panel is fixed but the edge (supported by web) can move. It is found that by supporting the machines on the edge, the center mode will not be excited but the combined mode of edge and center mode can give rise to significant noise radiation. A honeycomb panel with high resonance frequency is used to reduce the vibration transmission from this combined mode. The design can be used as an alternative to floating slab for reducing noise. Copyright © 2006 by The Japan Society of Mechanical Engineers.