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Laser hardening of metals occurs under the influence of a shock wave, which changes the distribution and density of one-dimensional defects - dislocations. There is a relationship between the density of dislocations, the grain size and the…

Optics · Physics 2026-01-21 A. G. Sukharev

We address a three-dimensional, coarse-grained description of dislocation networks at grain boundaries between rotated crystals. The so-called amplitude expansion of the phase-field crystal model is exploited with the aid of finite element…

Materials Science · Physics 2018-05-31 Marco Salvalaglio , Rainer Backofen , K. R. Elder , Axel Voigt

The continuum theory of dislocations, as developed predominantly by Kr\"oner and Kosevich, views each dislocation as a source of incompatibility of strains. We show that this concept can be employed efficiently in the Landau free energy…

Materials Science · Physics 2010-07-19 R. Gröger , T. Lookman

Dislocation pinning plays a vital role in the plastic behaviour of a crystalline solid. Here we report the first observation of the damped oscillations of a mobile dislocation after it gets pinned at an obstacle in the presence of a…

Materials Science · Physics 2010-12-24 M. Bhattacharya , A. Dutta , P. Mukherjee , N. Gayathri , P. Barat

Knowledge about grain boundary migration is a prerequisite for understanding and ultimately modulating the properties of polycrystalline materials. Evidence from experiments and molecular dynamics (MD) simulations suggests that the…

Materials Science · Physics 2021-12-08 Mahi Gokuli , Brandon Runnels

The viscoplastic deformation (creep) of crystalline materials under constant stress involves the motion of a large number of interacting dislocations. Analytical methods and sophisticated `dislocation-dynamics' simulations have proved very…

Statistical Mechanics · Physics 2009-11-07 M. -Carmen Miguel , Alessandro Vespignani , Stefano Zapperi , Jerome Weiss , Jean-Robert Grasso

We present results from microscopic mode coupling theory generalized to colloidal dispersions under shear in an integration-through-transients formalism. Stress-strain curves in start-up shear, flow curves, and normal stresses are…

Soft Condensed Matter · Physics 2015-06-19 Christian P. Amann , Matthias Fuchs

The present paper extends the thermodynamic dislocation theory initiated by Langer, Bouchbinder and Lookman [2010] to non-uniform finite plastic deformations. The equations of motion are derived from the variational equation involving the…

Materials Science · Physics 2019-02-20 Khanh Chau Le

Granular materials such as sand, powders, and food grains are ubiquitous in civil engineering, geoscience, agriculture, and medicine. While the influence of friction between the grains on the static structure of these systems is well…

Soft Condensed Matter · Physics 2024-05-16 Qinghao Mao , Yujie Wang , Walter Kob

Shear coupling implies that all grain boundary (GB) migration necessarily creates mechanical stresses/strains and is a key component to the evolution of all polycrystalline microstructures. We present MD simulation data and theoretical…

Materials Science · Physics 2020-11-04 Kongtao Chen , Jian Han , Spencer L. Thomas , David J. Srolovitz

Grain rotation and grain boundary (GB) sliding are two important mechanisms for grain coarsening and plastic deformation in nanocrystalline materials. They are in general coupled with GB migration and the resulting dynamics, driven by…

Materials Science · Physics 2014-12-30 Anup Basak , Anurag Gupta

By means of linear theory of elastoplasticity, solutions are given for screw and edge dislocations situated in an isotropic solid. The force stresses, strain fields, displacements, distortions, dislocation densities and moment stresses are…

Materials Science · Physics 2007-05-23 Markus Lazar

The strength of the lithosphere is typically modelled based on constitutive equations for steady-state flow. However, models of lithospheric flexure reveal differences in lithospheric strength that are difficult to reconcile based on such…

Twist grain boundaries are widely observed in lamellar phases of block copolymers. A mesoscopic model of the copolymer is used to obtain stationary configurations that include a twist grain boundary, and to analyze their stability against…

Soft Condensed Matter · Physics 2008-04-15 Xusheng Zhang , Zhi-Feng Huang , Jorge Viñals

The study-to-study variability of bedload flux measurements in turbulent sediment transport borders an order of magnitude, even for idealized laboratory conditions. This uncertainty stems from physically poorly supported, empirical methods…

In a granular material, a macroscopically homogeneous deformation does not correspond to a homogeneous displacement field when looking at the individual grains. The deviation of a grain displacement from the value dictated by the continuum…

Soft Condensed Matter · Physics 2012-10-16 Vincent Richefeu , Gaël Combe , Gioacchino Viggiani

We present an experimental system suitable for producing spherical crystals and for observing the distribution of lattice defects (disclinations and dislocations) on a significant fraction (50%) of the sphere. The introduction of…

Soft Condensed Matter · Physics 2007-05-23 Thomas Einert , Peter Lipowsky , Jorg Schilling , Mark J. Bowick , Andreas Bausch

The imprint effect, a significant reliability challenge in ferroelectric memories, manifests as a shift in the coercive field during retention and endurance tests, ultimately degrading the usable memory window. \rv{While traditional models…

Materials Science · Physics 2025-12-17 Huanhuan Tian , Jianguo Yang , Ming Liu

We extend our earlier shear-transformation-zone (STZ) theory of amorphous plasticity to include the effects of thermally assisted molecular rearrangements. This version of our theory is a substantial revision and generalization of…

Materials Science · Physics 2009-11-10 M. L. Falk , J. S. Langer , L. Pechenik

The static stress needed to depin a 2D edge dislocation, the lower dynamic stress needed to keep it moving, its velocity and displacement vector profile are calculated from first principles. We use a simplified discrete model whose far…

Materials Science · Physics 2009-11-10 A. Carpio , L. L. Bonilla