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Related papers: Dislocations in the elastic fields of randomly dis…

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This paper focuses on the connections between four stochastic and deterministic models for the motion of straight screw dislocations. Starting from a description of screw dislocation motion as interacting random walks on a lattice, we prove…

Analysis of PDEs · Mathematics 2020-09-11 Thomas Hudson , Patrick van Meurs , Mark A. Peletier

Two-dimensional simulations of the coarsening process of the isotropic/smectic-A phase transition are presented using a high-order Landau-de Gennes type free energy model. Defect annihilation laws for smectic disclinations, elementary…

Soft Condensed Matter · Physics 2008-06-30 Nasser Mohieddin Abukhdeir , Alejandro D Rey

We give a bird's-eye view of the plastic deformation of crystals aimed at the statistical physics community, and a broad introduction into the statistical theories of forced rigid systems aimed at the plasticity community. Memory effects in…

In this thesis I discuss analytical approaches to disordered systems using field theory. Disordered systems are characterized by a random energy landscape due to heterogeneities, which remains fixed on the time scales of the phenomena…

Disordered Systems and Neural Networks · Physics 2013-12-30 Alexander Dobrinevski

The elastic energy functional of a system of discrete dislocation lines is well known from dislocation theory. In this paper we demonstrate how the discrete functional can be used to systematically derive approximations which express the…

Materials Science · Physics 2015-12-02 Michael Zaiser

The interaction between dislocations is fundamental to plastic deformation, work hardening, and defect accumulation. While extensive research has focused on the impact of solutes on individual dislocations, how solutes affect…

Materials Science · Physics 2024-09-25 Jie Hou , Ducheng Peng , Xiang-Shan Kong , Huiqiu Deng , Wangyu Hu , Cheng Chen , Jun Song

To understand how dislocations form ordered structures during the deformation of metals, we perform computer simulation studies of the dynamics and patterning of screw dislocations in two dimensions. The simulation is carried out using an…

Materials Science · Physics 2007-05-23 Robin L. B. Selinger , Brian B. Smith , Wei-Dong Luo

The dynamics of dislocations is reported to exhibit glassy properties. We study numerically various versions of 2d edge dislocation systems in the absence of externally applied stress. Two types of glassy behavior are identified: (i)…

Disordered Systems and Neural Networks · Physics 2009-11-13 B. Bako , I. Groma , G. Gyorgyi , G. T. Zimanyi

The elastic moduli of four numerical random isotropic packings of Hertzian spheres are studied. The four samples are assembled with different preparation procedures, two of which aim to reproduce experimental compaction by vibration and…

Materials Science · Physics 2007-11-19 I. Agnolin , J. -N. Roux

Topological dislocations in otherwise periodic lattices represent global structural defects that, nevertheless, typically leave the lattice periodicity intact far from the dislocation. Such dislocations arise in diverse physical systems…

An exactly solvable phase-field theory of dislocation dynamics, strain hardening and hysteresis in ductile single crystals is developed. The theory accounts for: an arbitrary number and arrangement of dislocation lines over a slip plane;…

Materials Science · Physics 2009-11-07 M. Koslowski , A. M. Cuitiño , M. Ortiz

Dislocation systems exhibit well known scaling properties such as the Taylor relationship between flow stress and dislocation density, and the "law of similitude" linking the flow stress to the characteristic wavelength of dislocation…

Materials Science · Physics 2015-06-19 Michael Zaiser , Stefan Sandfeld

We derive a continuum-level plasticity model for polycrystalline materials in the high energy density regime, based on a single dislocation density and single mobility mechanism, with an evolution model for the dislocation density. The…

Whereas disclination defects are energetically prohibitive in two-dimensional flat crystals, their existence is necessary in crystals with spherical topology, such as viral capsids, colloidosomes or fullerenes. Such a geometrical…

Soft Condensed Matter · Physics 2020-07-01 Ireth García-Aguilar , Piermarco Fonda , Luca Giomi

The two-dimensional dislocation dynamics approach has been recently used for analyzing plastic deformation in metals and alloys at elevated temperatures. The two-dimensional approach, however, only accounts for the dislocation climbing…

Materials Science · Physics 2018-01-29 Amirreza Keyhani

In seeking to understand at a microscopic level the response of dislocations to stress we have undertaken to study as completely as possible the simplest case: a single dislocation in a two dimensional crystal. The intention is that results…

Materials Science · Physics 2007-05-23 N. Bailey , J. Sethna , C. Myers

A theory of flow stress, including the yield strength is proposed for the class of PC materials with equilibrium defect structure (EDS), which is established in the PC material after series of $N_0$ similar treatments of severe plastic…

Materials Science · Physics 2021-03-09 Alexander A. Reshetnyak

Dislocation velocities and mobilities are studied by Molecular Dynamics simulations for edge and screw dislocations in pure aluminum and nickel, and edge dislocations in Al-2.5%Mg and Al-5.0%Mg random substitutional alloys using EAM…

Materials Science · Physics 2009-11-10 David L. Olmsted , Louis G. Hector , W. A. Curtin , R. J. Clifton

Plastic deformation mediated by collective dislocation dynamics is investigated in the two-dimensional phase-field crystal model of sheared single crystals. We find that intermittent fluctuations in the dislocation population number…

Materials Science · Physics 2015-01-05 Jens M. Tarp , Luiza Angheluta , Joachim Mathiesen , Nigel Goldenfeld

We develop a model for the gliding of dislocations and plasticity in solid He-4. This model takes into account the Peierls barrier, multiplication and interaction of dislocations, as well as classical thermally and mechanically activated…