In the presence of dislocations, the elastic deformation tensor F is not a gradient but satisfies the condition Curl F = Lambda(T)(L) (with the dislocation density 3 L a tensor-valued measure concentrated in the dislocation L). Then F is an element of L-p with 1 <= p < 2. This peculiarity is at the origin of the mathematical difficulties encountered by dislocations at the mesoscopic scale, which are here modeled by integral 1-currents free to form complex geometries in the bulk. In this paper, we first consider an energy-minimization problem among the couples (F, L) of strains and dislocations, and then we exhibit a constraint reaction field arising at minimality due to the satisfaction of the condition on the deformation curl, hence providing explicit expressions of the Piola-Kirchhoff stress and PeachKoehler force. Moreover, it is shown that the Peach-Koehler force is balanced by a defect-induced configurational force, a sort of line tension. The functional spaces needed to mathematically represent dislocations and strains are also analyzed and described in a preliminary part of the paper.

Scala, R., VAN GOETHEM, N. (2016). Constraint reaction ant the Peach-Koehler force for dislocation networks. MATHEMATICS AND MECHANICS OF COMPLEX SYSTEMS, 4(2), 105-138 [10.2140/memocs.2016.4.105].

Constraint reaction ant the Peach-Koehler force for dislocation networks

SCALA R;
2016-01-01

Abstract

In the presence of dislocations, the elastic deformation tensor F is not a gradient but satisfies the condition Curl F = Lambda(T)(L) (with the dislocation density 3 L a tensor-valued measure concentrated in the dislocation L). Then F is an element of L-p with 1 <= p < 2. This peculiarity is at the origin of the mathematical difficulties encountered by dislocations at the mesoscopic scale, which are here modeled by integral 1-currents free to form complex geometries in the bulk. In this paper, we first consider an energy-minimization problem among the couples (F, L) of strains and dislocations, and then we exhibit a constraint reaction field arising at minimality due to the satisfaction of the condition on the deformation curl, hence providing explicit expressions of the Piola-Kirchhoff stress and PeachKoehler force. Moreover, it is shown that the Peach-Koehler force is balanced by a defect-induced configurational force, a sort of line tension. The functional spaces needed to mathematically represent dislocations and strains are also analyzed and described in a preliminary part of the paper.
2016
Scala, R., VAN GOETHEM, N. (2016). Constraint reaction ant the Peach-Koehler force for dislocation networks. MATHEMATICS AND MECHANICS OF COMPLEX SYSTEMS, 4(2), 105-138 [10.2140/memocs.2016.4.105].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/1087444