Open AccessStatistical analysis of dislocation dynamics during viscoplastic deformation from acoustic emission
Author(s) -
Weiss Jérôme,
Lahaie Franz,
Grasso Jean Robert
Publication year - 2000
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/1999jb900312
Subject(s) - viscoplasticity , creep , brittleness , dislocation , dislocation creep , power law , mechanics , materials science , deformation (meteorology) , acoustic emission , physics , classical mechanics , condensed matter physics , constitutive equation , mathematics , thermodynamics , composite material , statistics , finite element method
We present experimental data of acoustic emission (AE) induced by dislocation motion during “pure” viscoplastic (ductile) deformation of singlecrystals and polycrystals of ice which provide opportunity to revisit collective dislocation dynamics as a critical phenomenon, as recently proposed for brittle fracturing. The data were recorded during compression and torsion creep experiments. AE statistics of power law type were systematically obtained under different experimental conditions. Among the possible candidates for such a system with threshold dynamics exhibiting power law statistics, critical points, disordered first‐order transitions, and self‐organized criticality should be considered. The revisitation of dislocation dynamics as a critical phenomenon allows rationalization of collective effects as well as of the heterogeneity and complexity of viscoplastic deformation of crystalline materials. Such critical behavior implies that dislocation avalanches and strain localizations are unpredictible, in a deterministic sense, in space, time, and energy domains and that large plastic instabilities account for most of the viscoplastic deformation.