Study on the Vibration-Damping Mechanism of Granular Dampers Based on the Discrete Element Method

Granular damping is a passive vibration control method that has attracted considerable attention in mechanical and structural vibration reduction. To reveal the energy dissipation mechanism of granular dampers under sinusoidal excitation, this study develops a numerical model of a granular damper based on the discrete element method (DEM). First, two damper construction methods—using particle elements and clump elements—are compared, and the clump element approach is selected to construct the damper. The friction coefficient and normal critical damping ratio are then calibrated using the Hertz contact model and single-particle bounce experiments. On this basis, a forced vibration system with a virtual spring is established, and numerical simulations are carried out under three sinusoidal excitation conditions: 0.4 cm-15 Hz, 1.0 cm-15 Hz, and 0.4 cm-45 Hz. The damping mechanism is analyzed from an energy perspective, with discussion of the impact force, displacement, and velocity responses. The results show that the damping particles accelerate the system’s approach to steady-state vibration. Energy dissipation occurs mainly during collisions between the damping particles and the inner wall of the damper, and collision dissipation is greater than friction dissipation. When the particles detach from the wall, the inter-particle forces are very small, and the energy dissipation is negligible. The particle–wall impact force exhibits a multi-peak profile, and the force–time ratio increases with excitation intensity. These findings deepen the understanding of granular damping mechanisms and provide a reference for the design and optimization of granular dampers.