title: Rupture cascades in a discrete element model of a porous sedimentary rock.
abstract: We investigate the scaling properties of the sources of crackling noise in a fully dynamic numerical model of sedimentary rocks subject to uniaxial compression. The model is initiated by filling a cylindrical container with randomly sized spherical particles that are then connected by breakable beams. Loading at a constant strain rate the cohesive elements fail, and the resulting stress transfer produces sudden bursts of correlated failures, directly analogous to the sources of acoustic emissions in real experiments. The source size, energy, and duration can all be quantified for an individual event, and the population can be analyzed for its scaling properties, including the distribution of waiting times between consecutive events. Despite the nonstationary loading, the results are all characterized by power-law distributions over a broad range of scales in agreement with experiments. As failure is approached, temporal correlation of events emerges accompanied by spatial clustering.
authors.affiliation: Department of Theoretical Physics, University of Debrecen, P.O. Box 5, H-4010 Debrecen, Hungary.
authors.forename: Ferenc
authors.initials: F
authors.lastname: Kun
authors.affiliation: Department of Theoretical Physics, University of Debrecen, P.O. Box 5, H-4010 Debrecen, Hungary.
authors.forename: Imre
authors.initials: I
authors.lastname: Varga
authors.affiliation: School of Geosciences, University of Edinburgh, EH9 3JW Edinburgh, United Kingdom and Institute for Geophysics and Meteorology, University of Cologne, Cologne, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Lennartz-Sassinek
authors.affiliation: School of Geosciences, University of Edinburgh, EH9 3JW Edinburgh, United Kingdom.
authors.forename: Ian G
authors.initials: IG
authors.lastname: Main