Related Experiment Video
Updated: Aug 7, 2026

Full-field Strain Measurements for Microstructurally Small Fatigue Crack Propagation Using Digital Image Correlation Method
Published on: January 16, 2019
Atomic scale modelling of the cores of dislocations in complex materials part 2: applications
Andrew M Walker1, Julian D Gale, Ben Slater
1Davy Faraday Research Laboratory, The Royal Institution of Great Britain, 21 Albemarle Street, London, UK W1S 4BS. andrew.m.walker@anu.edu.au
Abstract:
In an accompanying article, we have described a methodology for the simulation of dislocations in structurally complex materials. We illustrate the applicability of this method through studies of screw dislocations in a structurally simple ionic ceramic (MgO), a molecular ionic mineral (forsterite, Mg2SiO4), a semi-ionic zeolite (siliceous zeolite A) and a covalent molecular crystalline material (the pharmaceutical, orthorhombic paracetamol-II). We focus on the extent of relaxation and the structure of the dislocation cores and comment on similarities and points of disparity between these materials. It is found that the magnitude of the relaxation varies from material to material and does not simply correlate with the magnitude of the principal elastic constants in an easily predictable fashion, or with the size of the cohesive lattice energy or length of the Burgers vector, which emphasises the need to model the non-linear forces and atomic structure of the core.
Related Concept Videos
Structures of Solids
Stress-Strain Diagram - Ductile Materials
Stress-Strain Diagram - Brittle Materials
Three-Dimensional Analysis of Strain
Elastic Strain Energy for Shearing Stresses
Imperfections in Crystal Structure: Stoichiometric Point Defects

