Parametric studies of the performance of particle dampers under harmonic excitation

Abstract

The performance of particle dampers under dynamic loads is very complicated and highly nonlinear; consequently, no guidelines currently exist for determining the optimum strategies for maximizing their behavior. The underlying interaction mechanics involve energy dissipation and momentum exchange. This paper presents the concept of ‘effective momentum exchange’ to quantify its influence on the performance of particle dampers with low volumetric filling ratio. The paper also evaluates the effects of a large number of system parameters (such as number, size and particle material, mass ratio, excitation frequency and amplitude level, coefficient of restitution, damping ratio of the primary system, and the coefficient of friction), using high-fidelity simulations based on the discrete-element method. It is shown that applying more particles with a high value of the coefficient of restitution can result in a broader range of acceptable response levels. For a given mass ratio, the particle type and size have minor effects on the primary system performance. Increasing the mass ratio can improve the damper's effectiveness but only up to a certain level. Friction is usually detrimental in low volumetric filling ratio particle dampers. It is shown that by using a properly designed particle damper, a lightly damped primary system can achieve a considerable reduction in its response with a small weight penalty. Copyright © 2009 John Wiley & Sons, Ltd.