The role of homogeneous nucleation in planar dynamic discrete dislocation plasticity

Research output: Contribution to journalArticlepeer-review

Authors

Colleges, School and Institutes

External organisations

  • Imperial College London

Abstract

Homogeneous nucleation of dislocations is the dominant dislocation generation mechanism at strain rates above 108 s-1; at those rates, homogeneous nucleation dominates the plastic relaxation of shock waves in the same way that Frank-Read sources control the onset of plastic flow at low strain rates. This article describes the implementation of homogeneous nucleation in dynamic discrete dislocation plasticity (D3P), a planar method of discrete dislocation dynamics (DDD) that offers a complete elastodynamic treatment of plasticity. The implemented methodology is put to the test by studying four materials - Al, Fe, Ni, and Mo - that are shock loaded with the same intensity and a strain rate of 1010 S-1. It is found that, even for comparable dislocation densities, the lattice shear strength is fundamental in determining the amount of plastic relaxation a material displays when shock loaded.

Details

Original languageEnglish
Article numberJAM-14-1551
JournalJournal of Applied Mechanics, Transactions ASME
Volume82
Issue number7
Early online date3 Jun 2015
Publication statusPublished - 1 Jul 2015

Keywords

  • impact, micromechanics, plasticity, stress analysis, wave propagation