Polymeric particle dampers under steady-state vertical vibrations

Numerical and experimental studies are made of the power dissipated by a granular medium as it undergoes sinusoidal vibrations in the same direction as gravity. The granular medium consists of spherical elastomeric particles that partially fill a box with rectangular cross section whose walls are made of thick blocks of Perspex. Simulations are obtained using a three-dimensional Discrete Element Method code. In order to find input parameters for use in the simulation studies, a specially designed test rig is used to measure the loss factor and dynamic stiffness of the particles. The power dissipation of the granular medium obtained from simulation is compared with that from a physical experiment and found to be in good agreement. The sensitivity of power dissipation to amplitude, frequency of excitation and friction coefficient is investigated.