Γ-Convergence Analysis of Systems of Edge Dislocations: The Self Energy Regime

This paper deals with the elastic energy induced by systems of straight edge dislocations in the framework of linearized plane elasticity. The dislocations are introduced as point topological defects of the displacement-gradient fields. Following the core radius approach, we introduce a parameter ε > 0 representing the lattice spacing of the crystal, we remove a disc of radius ε around each dislocation and compute the elastic energy stored outside the union of such discs, namely outside the core region. Then, we analyze the asymptotic behaviour of the elastic energy as ε → 0, in terms of Γ-convergence. We focus on the self energy regime of order log 1/ε; we show that configurations with logarithmic diverging energy converge, up to a subsequence, to a finite number of multiple dislocations and we compute the corresponding Γ-limit. © 2012 Springer-Verlag.