Vibrational energy dissipation mechanisms in granular dampers

Granular damping has been found to be a robust solution for attenuating noise and vibration in difficult operating conditions such as space and aviation applications. However, despite its huge potential, it has never been the first design option for enhancing the damping of structures in practical applications. The primary reason of this is that the energy dissipation behaviour of a granular damper exhibits amplitude and frequency dependent non-linearity. The work presented here investigates the link between the non-linear granular energy dissipation and dynamic motional behaviour of particles considering a broad range of excitation amplitude and frequency. The optimum operating conditions of granular dampers are obtained. The most significant factors which control the optimum conditions are determined to provide reliable guidance for the efficient design of granular dampers. As an extension to the relationship developed between the granular motional phase and energy dissipation, the influence of particle shape is systematically studied using a large collection of non-spherical particle shapes.