1Department of Applied Science for Electronics and Materials, Kyushu University, 6-1 Kasuga 816-8580, Japan
2Department of Earth and Environmental Sciences, Nagoya University, Furocho, Chikusa, Nagoya 464-8601, Japan
Received: 18 Apr 2013 – Revised: 29 Jul 2013 – Accepted: 06 Nov 2013 – Published: 03 Jan 2014
Abstract. Penetration-resistant force and acoustic emission (AE) from a plunged granular bed are experimentally investigated through their power law distribution forms. An AE sensor is buried in a glass bead bed. Then, the bed is slowly penetrated by a solid sphere. During the penetration, the resistant force exerted on the sphere and the AE signal are measured. The resistant force shows power law relation to the penetration depth. The power law exponent is independent of the penetration speed, while it seems to depend on the container's size. For the AE signal, we find that the size distribution of AE events obeys power laws. The power law exponent depends on grain size. Using the energy scaling, the experimentally observed power law exponents are discussed and compared to the Gutenberg–Richter (GR) law.
Matsuyama, K. and Katsuragi, H.: Power law statistics of force and acoustic emission from a slowly penetrated granular bed, Nonlin. Processes Geophys., 21, 1-8, doi:10.5194/npg-21-1-2014, 2014.