Acoustic emission monitoring of crushing of an analogue granular material

Abstract

A two-dimensional analogue material formed of rod cylinders of chalk is tested under onedimensional oedometric loading conditions. Passive non-destructive Acoustic Emission (AE) monitoring technique is used to document the occurrence of crushing of individual particles. While the AE activity is recorded by a sensor placed on the sample boundaries, the AE signals are also corroborated with the observations based on video records of the exposed face of the 2D sample, as well as vertical loading and displacement measurements of the global sample. In the process, one-dimensional tests on individual cylindrical rods were also conducted and their AE crushing signatures compared with the AE data recorded at the 2D sample scale. While AE signal features can capture the particle crushing in the 2D granular systems, their occurrence shows high complexities driven by internal crushing particle mechanisms and geometrical position of particles with respect to the AE monitoring device. The frequency content of AE signals shows some evidence of the existence of an AE signature for a typical particle crushing mechanism, which may be a consequence of the dynamic properties of the whole system.

Micromechanical Behavior of Granular Soils Characterized by Acoustic Emission

“…An acoustic wave in granular soils generally stems from particle interactions such as particle sliding or crushing. Extracting and interpreting the parameter information (e.g., AE hit or energy rate) carried by AE waveforms provides a quantitative analysis of the failure level in a stressed material [8,[28][29][30][31][32][33][34][35]. Dixon et al [36] reported the availability of AE technique combined with active waveguides in terrigenous type soil slope monitoring through field trials, and a relation between AE rate and deformation rate of soil was established to evaluate the stability of soil slopes.…”