Avalanches in 2D dislocation systems: Plastic yielding is not depinning

Péter Dusán Ispánovity, Lasse Laurson, Michael Zaiser, István Groma, Stefano Zapperi, Mikko J. Alava

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Abstract

We study the properties of strain bursts (dislocation avalanches) occurring in two-dimensional discrete dislocation dynamics models under quasistatic stress-controlled loading. Contrary to previous suggestions, the avalanche statistics differ fundamentally from predictions obtained for the depinning of elastic manifolds in quenched random media. Instead, we find an exponent τ=1 of the power-law distribution of slip or released energy, with a cutoff that increases exponentially with the applied stress and diverges with system size at all stresses. These observations demonstrate that the avalanche dynamics of 2D dislocation systems is scale-free at every applied stress and, therefore, cannot be envisaged in terms of critical behavior associated with a depinning transition.

Original languageEnglish
Article number235501
JournalPhysical review letters
Volume112
Issue number23
DOIs
Publication statusPublished - jún. 13 2014

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ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Ispánovity, P. D., Laurson, L., Zaiser, M., Groma, I., Zapperi, S., & Alava, M. J. (2014). Avalanches in 2D dislocation systems: Plastic yielding is not depinning. Physical review letters, 112(23), [235501]. https://doi.org/10.1103/PhysRevLett.112.235501