Granular dampers: does particle shape matter?

Abstract

By means of particle-based numerical simulations using the discrete element method, we address the question of how the performance of granular dampers is affected by the shape of the granular particles. In consistence with previous experiments performed with nearly spherical particles we find that independently of the particles' shape, the granular system is characterized by a gas-like regime for small amplitudes of the container's oscillation and by a collect-and-collide regime for large amplitude forcing. Both regimes are separated by an optimal operation mode-the critical amplitude of the damping oscillation for which the energy dissipation is maximal-which is independent of the particle shape for given conditions of particle mass, material properties and number of particles. However, in the gas-like regime, we find that spherical particles lead to more efficient energy dissipation compared to complex shaped particles of the same mass. In this regime, a dependence on the damper's efficiency on the particle shape is found. performance and operation mode of granular dampers, that is, the average value of total dissipated energy per oscillation cycle, in response to the vibration amplitude [28,29].

Rheological response of nonspherical granular flows down an incline

“…Although granular flows are often composed of nonspherical shapes, most of the research usually considers spherical particles [13][14][15][16][17][18][19]. However, it is known that particle shape may give rise to a different mechanical response and complex flow patterns [20][21][22][23][24][25][26][27][28][29][30]. Interestingly, the collective motion of elongated particles usually induces particles to orient themselves along a preferred direction, forming an angle with the streamlines [20][21][22][23].…”

Homogenization of granular pipe flow by means of helical inner-wall texture

“…1. While a detailed description of the model has been presented before [14][15][16][17][18], in the following we focus on the description of the numerical experiments of granular pipe flow and, in the subsequent section, the model of the helix-shaped texture to homogenize the particle transport [14].…”

Effect of particle shape on the efficiency of granular dampers

“…Moreover, while the circularity is a measure inherent to two-dimensional objects [13], the aspect ratio of particle shapes #12 − #14 can be computed for each one of the planes defined in Table 1 and the results are displayed in this table. In the DEM model, the multispheres particles are treated as rigid bodies, the translational and rotational motion of which results from the forces acting on the constituent beads. These forces are computed using noncohesive inter-particle force model based on Cundall and Strack [14] and described in detail elsewhere [15]. In the model, the beads are treated as viscoelastic and friction is neglected [15].…”