Calculus of Variations and Geometric Measure Theory

P. Cesana - L. De Luca - M. Morandotti

Semi-discrete modeling of systems of wedge disclinations and edge dislocations via the Airy stress function method

created by morandott on 06 Jul 2022
modified on 05 Jan 2024


Published Paper

Inserted: 6 jul 2022
Last Updated: 5 jan 2024

Journal: SIAM Journal on Mathematical Analysis
Volume: 56
Number: 1
Pages: 79-136
Year: 2024
Doi: 10.1137/22M1523443

ArXiv: 2207.02511 PDF


We present a variational theory for lattice defects of rotational and translational type. We focus on finite systems of planar wedge disclinations, disclination dipoles, and edge dislocations, which we model as the solutions to minimum problems for isotropic elastic energies under the constraint of kinematic incompatibility. Operating under the assumption of planar linearized kinematics, we formulate the mechanical equilibrium problem in terms of the Airy stress function, for which we introduce a rigorous analytical formulation in the context of incompatible elasticity. Our main result entails the analysis of the energetic equivalence of systems of disclination dipoles and edge dislocations in the asymptotics of their singular limit regimes. By adopting the regularization approach via core radius, we show that, as the core radius vanishes, the asymptotic energy expansion for disclination dipoles coincides with the energy of finite systems of edge dislocations. This proves that Eshelby's kinematic characterization of an edge dislocation in terms of a disclination dipole is exact also from the energetic standpoint.

Keywords: linearized elasticity, edge dislocations, Wedge Disclinations, Airy Stress Function