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Dynamic overshoot in alpha-iron by atomistic simulations

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Original languageEnglish
Pages (from-to)521-542
Number of pages22
JournalModelling and simulation in materials science and engineering
Volume6
Issue number5
Publication statusPublished - Sep 1998
EventInternational Conference on Computational Physics - SANTA CRUZ, United Kingdom
Duration: 25 Aug 199728 Aug 1997

Abstract

We present large-scale molecular dynamic simulations of microcrack growth in alpha-iron based on an N-body potential model which gives a goad description of defect energetics, anisotropic elasticity and phonon frequency spectra. We demonstrate dynamic overshoot of a pre-existing microcrack under impact loading. We show that the basic behaviour of the simulations is in agreement with the predictions of continuum models. Dynamic phenomena, such as scattering of stress waves at crack fees, acoustic emission (due to bond breakage) and reflections of the stress waves from sample borders, are studied here in detail. The results on microcrack growth, unimpeded by the wave reflections from external sample borders, indicate that under fast loading or at high crack velocities, i.e. under high strain rates, transient twin formation is possible from the crack tip with later detwinning at free crack faces as the crack advances: a twinning equivalent to virtual Knott dislocations.

    Research areas

  • DISLOCATION EMISSION, COMPUTER-SIMULATION, MOLECULAR-DYNAMICS, CRACK, FRACTURE, METALS

Event

International Conference on Computational Physics

25/08/9728/08/97

United Kingdom

Event: Conference

ID: 16872226