Compaction dynamics of a granular media under vertical tapping

TL;DR

This paper investigates how granular media compact under repeated vertical taps, showing slow densification with a stretched exponential relaxation and a relation between tap intensity and relaxation time, with nearly uniform densification.

Contribution

It provides new experimental insights into the relaxation dynamics and densification process of granular media under vertical tapping, highlighting the role of tap intensity.

Findings

Densification follows a stretched exponential law.

Relaxation time depends on tap intensity via an Arrhenius-like relation.

Densification is nearly homogeneous throughout the packing.

Abstract

We report new experimental results on granular compaction under consecutive vertical taps. The evolution of the mean volume fraction and of the mean potential energy of a granular packing presents a slow densification until a final steady-state, and is reminiscent to usual relaxation in glasses via a stretched exponential law. The intensity of the taps seems to rule the characteristic time of the relaxation according to an Arrhenius's type relation >. Finally, the analysis of the vertical volume fraction profile reveals an almost homogeneous densification in the packing.