Universität zu Köln

Tell, Karsten, Dreissigacker, Christoph, Tchapnda, Alberto Chiengue, Yu, Peidong and Sperl, Matthias ORCID: 0000-0001-9525-0368 (2020). Acoustic waves in granular packings at low confinement pressure. Rev. Sci. Instrum., 91 (3). MELVILLE: AMER INST PHYSICS. ISSN 1089-7623

Full text not available from this repository.

Abstract

Elastic properties of a granular packing show a nonlinear behavior determined by its discrete structure and nonlinear inter-grain force laws. Acoustic waves show a transition from constant, pressure-dependent sound speed to a shock-wave-like behavior with an amplitude-determined propagation speed. This becomes increasingly visible at low static confinement pressure as the transient regime shifts to lower wave amplitudes for lower static pressure. In microgravity, confinement pressure can be orders of magnitude lower than in a ground-based experiment. In addition, the absence of hydrostatic gradients allows for much more homogeneous and isotropic pressure distribution. We present a novel apparatus for acoustic wave transmission measurements at such low packing pressures. A pressure control loop is implemented by using a microcontroller that monitors static force sensor readings and adjusts the position of a movable wall with a linear-motor until the desired pressure is reached. Measurements of acoustic waves are possible using accelerometers embedded in the granular packing as well as piezos. For excitation, we use a voice-coil-driven wall, with a large variety of signal shapes, frequencies, and amplitudes. This enables experiments in both the linear and strongly nonlinear regimes.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Tell, Karsten UNSPECIFIED UNSPECIFIED UNSPECIFIED Dreissigacker, Christoph UNSPECIFIED UNSPECIFIED UNSPECIFIED Tchapnda, Alberto Chiengue UNSPECIFIED UNSPECIFIED UNSPECIFIED Yu, Peidong UNSPECIFIED UNSPECIFIED UNSPECIFIED Sperl, Matthias UNSPECIFIED orcid.org/0000-0001-9525-0368 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-342662
DOI:	10.1063/1.5122848
Journal or Publication Title:	Rev. Sci. Instrum.
Volume:	91
Number:	3
Date:	2020
Publisher:	AMER INST PHYSICS
Place of Publication:	MELVILLE
ISSN:	1089-7623
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language EFFECTIVE ELASTIC-MODULI Multiple languages Instruments & Instrumentation; Physics, Applied Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/34266