Vibrational dynamics of 3D granular media composed with polyhedral grains -- Din\'amica vibracional de un medio granular 3D compuesto de part\'iculas poli\'edricas

TL;DR

This study uses 3D contact dynamics simulations to investigate how polyhedral granular media respond vibrationally to harmonic forces, revealing scaling laws and the relationship between frequency, displacement, and compaction rate.

Contribution

It provides a novel analysis of vibrational dynamics in 3D polyhedral granular media, including scaling laws and the impact of frequency on compaction.

Findings

Displacement scales inversely with the square of frequency.

Mean compaction rate increases linearly then decreases with frequency.

An approximate force-displacement relation describes the system dynamics.

Abstract

By means of tree-dimensional contact dynamics simulations, we analyze the vibrational dynamics of a confined granular layer in response to harmonic forcing. The sample is composed of polyedric grains with a shape derived from digitalized ballast. The system involves a jammed state separating passive (loading) and active (unloading) states. We show that an approximate expression of the packing resistance force as a function of the displacement of the free retaining wall from the jamming position provides a good description of the dynamics. We study in detail the scaling of displacements and velocities with loading parameters. In particular, we find that, for a wide range of frequencies, the data collapse by scaling the displacements with the inverse square of frequency, the inverse of the force amplitude and the square of gravity. We show that the mean compaction rate increases linearly with frequency up to a characteristic frequency of 10 Hz and then it declines in inverse proportion to frequency.