A Dual Vibration Absorber for Vibration Suppression of Harmonically Forced Systems

Abstract

In this work, a dual absorber setup is proposed for the reduction of the harmonic response of single degree of freedom systems. The main system is a mass spring damper excited with a harmonic force. This dual absorber setup combines both the classical and platform absorbers. The primary system sits of the platform absorber and has the classical absorber attached to it. This yields a harmonically forced three degrees of freedom system. The objective is to reduce the maximum of the frequency response function of the primary system for all forcing frequencies. First, the objective function is defined and written in terms of dimensionless parameters. Then, a numerical technique based on both the genetic algorithm and the search simplex method is used to calculate the optimal system parameters. The problem is solved for a set of values of primary system damping and upper absorber mass. It is shown that the dual absorber performance increases with the increasing of the upper absorber mass for a given platform mass. And, as in the case of the platform absorber, an optimal absorber mass exists for the lower absorber. Finally, the performance of the dual absorber is compared to those of the classical and platform absorbers. It is shown that the dual absorber outperforms both the classical and platform absorbers.