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The kinetics of dislocations is studied with computer simulation at loadings of different intensity. It is established that the dislocations have a few different structural states. The dislocations "with the micropore" play important role…

Materials Science · Physics 2007-05-23 L. S. Metlov

The starting point of our analysis is a class of one-dimensional interacting particle systems with two species. The particles are confined to an interval and exert a nonlocal, repelling force on each other, resulting in a nontrivial…

Analysis of PDEs · Mathematics 2018-01-17 Patrick van Meurs

Plasticity of two-dimensional discrete dislocation systems is studied. It is shown, that at some threshold stress level the response becomes stress-rate dependent. Below this stress level the stress-plastic strain relation exhibits…

Statistical Mechanics · Physics 2011-09-16 Péter Dusán Ispánovity

Microcrystals deform very differently from their macroscopic counterparts, displaying a size-dependent yield stress and intermittent plastic strain bursts. Here we demonstrate that size effects and strain bursts may be just two different…

Materials Science · Physics 2012-04-04 Valentina Beato , Michael Zaiser , Stefano Zapperi

The thermodynamic theory of dislocation-enabled plasticity is based on two unconventional hypotheses. The first of these is that a system of dislocations, driven by external forces and irreversibly exchanging heat with its environment, must…

Materials Science · Physics 2017-12-06 J. S. Langer

Pinning of dislocations at nanosized obstacles like precipitates, voids and bubbles, is a crucial mechanism in the context of phenomena like hardening and creep. The interaction between such an obstacle and a dislocation is often explored…

Materials Science · Physics 2014-10-22 A. Dutta , M. Bhattacharya , P. Barat

Plastic deformation of crystalline and amorphous matter often involves intermittent local strain burst events. To understand the physical background of the phenomenon a minimal stochastic mesoscopic model was introduced, where…

Materials Science · Physics 2017-02-15 Péter Dusán Ispánovity , Dániel Tüzes , Péter Szabó , Michael Zaiser , István Groma

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

Here we present a model to study the micro-plastic regime of a stress-strain curve. In this model an explicit dislocation population represents the mobile dislocation content and an internal shear-stress field represents a mean-field…

Materials Science · Physics 2015-06-05 P. M. Derlet , R. Maaß

Crystal dislocations govern the plastic mechanical properties of materials but also affect the electrical and optical properties. However, a fundamental and quantitative quantum-mechanical theory of dislocation remains undiscovered for…

Materials Science · Physics 2017-01-27 Mingda Li , Wenping Cui , M. S. Dresselhaus , Gang Chen

The dynamics of dislocations can be formulated in terms of the evolution of continuous variables representing dislocation densities ('continuum dislocation dynamics'). We show for various variants of this approach that the resulting models…

Materials Science · Physics 2024-10-23 Yufan Zhang , Ronghai Wu , Michael Zaiser

We perform the discrete-to-continuum limit passage for a microscopic model describing the time evolution of dislocations in a one dimensional setting. This answers the related open question raised by Geers et al. in [GPPS13]. The proof of…

Analysis of PDEs · Mathematics 2014-11-05 Patrick van Meurs , Adrian Muntean

Stressed dislocation pattern formation in crystal plasticity at finite deformation is demonstrated for the first time. Size effects are also demonstrated within the same mathematical model. The model involves two extra material parameters…

Materials Science · Physics 2018-12-04 Rajat Arora , Amit Acharya

We study dislocation networks in the plane using the vectorial phase-field model introduced by Ortiz and coworkers, in the limit of small lattice spacing. We show that, in a scaling regime where the total length of the dislocations is…

Analysis of PDEs · Mathematics 2020-01-24 Sergio Conti , Adriana Garroni , Stefan Müller

A dislocation moving through a quasicrystal is leaving in its wake a fault denoted phason wall. For a two-dimensional model quasicrystal the disregistry energy of this phason wall is studied to determine possible Burgers vectors of the…

Materials Science · Physics 2008-02-03 R. Mikulla , P. Gumbsch , H. -R. Trebin

Mechanical deformation of amorphous solids can be described as consisting of an elastic part in which the stress increases linearly with strain, up to a yield point at which the solid either fractures or starts deforming plastically. It is…

Disordered Systems and Neural Networks · Physics 2020-03-25 Baoshuang Shang , Pengfei Guan , Jean-Louis Barrat

A two-dimensional (2D) dislocation continuum theory is being introduced. The present theory adds elastic rotation, dislocation density, and background stress to the classical energy density of elasticity. This theory contains four material…

Mesoscale and Nanoscale Physics · Physics 2015-10-15 Markus Lazar

We present a continuum model to determine the dislocation structure and energy of low angle grain boundaries in three dimensions. The equilibrium dislocation structure is obtained by minimizing the grain boundary energy that is associated…

Materials Science · Physics 2021-11-08 Xiaoxue Qin , Yejun Gu , Luchan Zhang , Yang Xiang

The theory of the depinning transition of elastic manifolds in random media provides a framework for the statistical dynamics of dislocation systems at yield. We consider the case of a single flexible dislocation gliding through a random…

Materials Science · Physics 2007-05-23 Stefano Zapperi , Michael Zaiser

When an amorphous solid is deformed homogeneously, the response exhibits heterogeneous plastic instabilities with localized cooperative rearrangement of cluster of particles. The heterogeneous behavior plays an important role in deciding…

Soft Condensed Matter · Physics 2022-01-31 Meenakshi L , Bhaskar Sen Gupta