ON PLASTIC-DEFORMATION AND THE DYNAMICS OF 3D DISLOCATIONS

Citation
Hm. Zbib et al., ON PLASTIC-DEFORMATION AND THE DYNAMICS OF 3D DISLOCATIONS, International journal of mechanical sciences, 40(2-3), 1998, pp. 113-127
Citations number
29
Categorie Soggetti
Mechanics,"Engineering, Mechanical
ISSN journal
00207403
Volume
40
Issue
2-3
Year of publication
1998
Pages
113 - 127
Database
ISI
SICI code
0020-7403(1998)40:2-3<113:OPATDO>2.0.ZU;2-5
Abstract
A three-dimensional (3D) mesoscopic model to simulate the collective d ynamic behavior of a large number of curved dislocations of finite len gths has been developed for the purpose of analyzing deformation patte rns and instabilities, including the formation of dislocation cell str uctures. Each curved dislocation is approximated by a piecewise contin uous array of straight line segments. The interactions among the segme nts, including line-tension and self-interactions, are treated explici tly. For longer-range interactions, the space is divided into a regula r cellular array and the elastic fields of the dislocations in a remot e cell approximated by a multipolar expansion, leading to an order N a lgorithm for the description of a cell containing N dislocations. For large arrays, the simulation volume is divided into cubical cells. A d iscrete random starting array is selected for the master cell and its nearest neighbors, which constitute an order 2 cell. Reflection bounda ry conditions are imposed for near-neighbor order 2 cells and so forth , creating an NaCl-type lattice array. The boundaries between the cell s are considered to be relaxed grain boundaries. That is, recovery wit hin the boundaries and rotation across them are considered to occur so that the boundaries have no associated elastic fields. This cell hier archy, coupled with the multipole expansion, is suitable for the use o f massively parallel computation, with individual cells assigned to se parate processors. (C) 1997 Published by Elsevier Science Ltd.