Suppression of bending waves in a beam using a tuned vibration absorber

This paper is concerned with the control of flexural waves in a beam using a tuned vibration absorber (TVA). The TVA may be located in the farfield or the nearfield of a time harmonic point force and it can be positioned to control both the downstream-transmitted power and that reflected upstream. Analytical and numerical investigations are presented. The effects of the incident evanescent wave on the optimal characteristics of the absorber are discussed when the TVA is located in the nearfield of the point force. If the TVA is located in the nearfield, the power transmitted past the TVA depends on four independent tuning parameters: the absorber frequency, the mass ratio, the structural damping of the TVA and the distance between the TVA and the point force. If the incident nearfield wave is insignificant, then this distance becomes unimportant in determining the optimal characteristics of the TVA. The net power propagating upstream is due to the superposition of the wave reflected from the TVA and that input by the point force and depends on all four parameters. Attention is focussed on finding the frequencies at which the minimum power is transmitted or the maximum power absorbed by the TVA. Experimental results are presented to validate the theoretical predictions. (c) 2005 Elsevier Ltd. All rights reserved.