Particle damping for passive vibration suppression: numerical modelling and experimental investigation

As a simple and passive means, particle damping provides vibration suppression with granular particles embedded within their containing holes in a vibrating structure. Unlike in traditional damping materials, mechanisms of energy dissipation of particle damping are primarily related to friction and impact phenomena which are highly non-linear. In the research work reported in the paper we investigate elastic beam and plate structures with drilled longitudinal holes filled with damping particles. Our focus is on the form of damping due to shear friction induced by strain gradient along the length of the structure. We present physical models to take into account of the shear frictional forces between particle layers and impacts of the particles with the containing holes. A numerical procedure is presented to predict the damping effect. Experimental tests of the beam and plate structures for various different damping treatments are also conducted. Model predictions are validated by experimental results. The particle damping is found to be remarkably strong for a broadband range. Moreover, the shear friction is determined to be the major contributing mechanism of damping, especially at a high volumetric packing ratio. The numerical and experimental findings suggest that the best damping effect might be achieved by using a design of multiple particle chambers involving an appropriate combination of the impact, friction and shear mechanisms, in contrast to a transverse-type particle or single-mass damper. (C) 2003 Elsevier Ltd. All rights reserved.