Dislocation pileups: topological features of stresses and strains

When averaged over half-spaces, the elastic stress and strain fields from d islocation pileups are shown to take a peculiar topological features of the form y/\y\, i.e., they undergo an abrupt change when passing through the p ileup plane. The average fields appear to be equivalent to the Somigliana d islocations and provides a description of strain boundaries in crystals suc h as the torsion boundary which represents a surface where the average rota tion field experience a topological jump. (C) 2001 Published by Elsevier Sc ience Ltd.