Mechanical impulse propagation in a packing of 3D spheres confined at constant pressure

Abstract

Mechanical impulse propagation in granular media depends strongly on the imposed confinement conditions. In this work, the propagation of sound in a granular packing contained by flexible walls that enable confinement under hydrostatic pressure conditions is investigated. This configuration also allows the form of the input impulse to be controlled by means of an instrumented impact pendulum. The main characteristics of mechan- ical wave propagation are analyzed, and it is found that the wave speed as function of the wave amplitude of the propagating pulse obeys the predictions of the Hertz contact law. Upon increasing the confinement pressure, a continuous transition from nonlinear to linear propagation is observed. Our results show that in the low-confinement regime, the attenuation increases with an increasing impulse amplitude for nonlinear pulses, whereas it is a weak function of the confinement pressure for linear waves.

6 pages, 7 figures

References in corpus (4)

• How Hertzian solitary waves interact with boundaries in a 1-D granular medium
• Shock Waves in Weakly Compressed Granular Media
• Dynamic weakening by acoustic fluidization during stick-slip motion
• Softening of Granular Packings with Dynamic Forcing

Cited by in corpus (6)

• Controlled viscosity in dense granular materials
• Induced and endogenous acoustic oscillations in granular faults
• Propagation and attenuation of pulses driven by low velocity normal impacts in granular media
• Acoustic Waves in Granular Packings at Low Confinement Pressure
• Effect of an interstitial fluid on the dynamics of three-dimensional granular media
• Synchronized oscillations and acoustic fluidization in confined granular materials