Universität zu Köln

Lennartz-Sassinek, S., Main, I. G., Zaiser, M. and Graham, C. C. (2014). Acceleration and localization of subcritical crack growth in a natural composite material. Phys. Rev. E, 90 (5). COLLEGE PK: AMER PHYSICAL SOC. ISSN 1550-2376

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Abstract

Catastrophic failure of natural and engineered materials is often preceded by an acceleration and localization of damage that can be observed indirectly from acoustic emissions (AE) generated by the nucleation and growth of microcracks. In this paper we present a detailed investigation of the statistical properties and spatiotemporal characteristics of AE signals generated during triaxial compression of a sandstone sample. We demonstrate that the AE event amplitudes and interevent times are characterized by scaling distributions with shapes that remain invariant during most of the loading sequence. Localization of the AE activity on an incipient fault plane is associated with growth in AE rate in the form of a time-reversed Omori law with an exponent near 1. The experimental findings are interpreted using a model that assumes scale-invariant growth of the dominating crack or fault zone, consistent with the Dugdale-Barenblatt process zone model. We determine formal relationships between fault size, fault growth rate, and AE event rate, which are found to be consistent with the experimental observations. From these relations, we conclude that relatively slow growth of a subcritical fault may be associated with a significantly more rapid increase of the AE rate and that monitoring AE rate may therefore provide more reliable predictors of incipient failure than direct monitoring of the growing fault.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Lennartz-Sassinek, S. UNSPECIFIED UNSPECIFIED UNSPECIFIED Main, I. G. UNSPECIFIED UNSPECIFIED UNSPECIFIED Zaiser, M. UNSPECIFIED UNSPECIFIED UNSPECIFIED Graham, C. C. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-423381
DOI:	10.1103/PhysRevE.90.052401
Journal or Publication Title:	Phys. Rev. E
Volume:	90
Number:	5
Date:	2014
Publisher:	AMER PHYSICAL SOC
Place of Publication:	COLLEGE PK
ISSN:	1550-2376
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language STRESS-CORROSION; FORESHOCKS; AFTERSHOCK; DAMAGE; MODEL; LAWS Multiple languages Physics, Fluids & Plasmas; Physics, Mathematical Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/42338