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Related papers: Dislocation Geometry in the TGB-A Phase: Linear Th…

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We use a discrete dislocation dynamics (DDD) approach to study the motion of a dislocation under strong stochastic forces that may cause bending and roughening of the dislocation line on scales that are comparable to the dislocation core…

Materials Science · Physics 2018-07-26 Jianhui Zhai , Michael Zaiser

Generic wave dislocations (phase singularities, optical vortices) in three dimensions have anisotropic local structure, which is analysed, with emphasis on the twist of surfaces of equal phase along the singular line, and the rotation of…

Optics · Physics 2009-11-10 M. R. Dennis

In the present work, we propose a novel model coupling phase-field, dislocation density based plasticity and damage. The dislocation density governing equations are constructed based on evolutions of mobile and immobile dislocations.…

Materials Science · Physics 2021-12-28 Ronghai Wu , Yufan Zhang

We develop and demonstrate the first general computational tool for finite deformation static and dynamic dislocation mechanics. A finite element formulation of finite deformation (Mesoscale) Field Dislocation Mechanics theory is presented.…

Materials Science · Physics 2020-06-24 Rajat Arora , Xiaohan Zhang , Amit Acharya

We investigate the depinning transition occurring in dislocation assemblies. In particular, we consider the cases of regularly spaced pileups and low angle grain boundaries interacting with a disordered stress landscape provided by solute…

Statistical Mechanics · Physics 2009-11-10 Paolo Moretti , M. -Carmen Miguel , Michael Zaiser , Stefano Zapperi

This paper develops the small strain continuum dislocation theory accounting for statistically stored dislocations and Taylor hardening for single crystals. As illustration, the problem of anti-plane constrained shear of single crystal…

Materials Science · Physics 2015-06-12 Khanh Chau Le , Pramio Sembiring , Thi Nhung Tran

A novel analysis of homogeneous nucleation of dislocations in sheared two-dimensional crystals described by periodized discrete elasticity models is presented. When the crystal is sheared beyond a critical strain $F=F_{c}$, the strained…

Materials Science · Physics 2008-05-09 I. Plans , A. Carpio , L. L. Bonilla

Grain boundaries (GBs) merge and grains disappear during microstructure evolution. However, the Peach-Koehler model predicts that particular stress states may reverse such a process by exerting differential Peach-Koehler forces on different…

Materials Science · Physics 2025-09-04 Wei Wan , Changxin Tang , Eric R Homer

According to recent experimental and numerical investigations if the characteristic size of a specimen is in the submicron size regime several new interesting phenomena emerge during the deformation of the samples. Since in such a systems…

Materials Science · Physics 2015-06-19 Istvan Groma , Zoltan Vandrus , Peter Dusan Ispanovity

We present a theory of the elasticity and fluctuations of the Smectic A and C phases in uniaxial, anisotropic disordered environments, e.g., stretched aerogel. We find that, bizarrely, the low-temperature, lower-symmetry Smectic $C$ phase…

Soft Condensed Matter · Physics 2013-05-29 Leiming Chen , John Toner

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

In classical elasticity theory the stress-field of a dislocation is characterized by a $1/r$-type singularity. When such a dislocation is considered together with an Allen-Cahn-type phase-field description for microstructure evolution this…

Materials Science · Physics 2021-07-02 M. Budnitzki , S. Sandfeld

The homotopy theory of topological defects in ordered media fails to completely characterize systems with broken translational symmetry. We argue that the problem can be understood in terms of the lack of rotational Goldstone modes in such…

Soft Condensed Matter · Physics 2009-09-14 Bryan Gin-ge Chen , Gareth P. Alexander , Randall D. Kamien

Using simulations of hard rods in smectic-A states, we find non-gaussian diffusion and heterogeneous dynamics due to the equilibrium periodic smectic density profiles, which give rise to permanent barriers for layer-to-layer diffusion. This…

Soft Condensed Matter · Physics 2009-12-15 A. Patti , D. El Masri , R. van Roij , M. Dijkstra

We report a first-principles density functional theory study on the role of grain boundary and dislocation loop in H blistering in W. At low temperature, the {\Sugma}3(111) tilt grain boundary, when combined with a vacancy of vanishing…

Materials Science · Physics 2015-05-27 W. Xiao , W. T. Geng

The liquid crystalline compound, forming the glass of the smectic C$_A$* phase, is investigated by the X-ray diffraction in the 18-298 K range. The characteristic distances within the smectic C$_A$* phase are determined. The electron…

We propose an energy-consistent mathematical model for motion of dislocation curves in elastic materials using the idea of phase field model. This reveals a hidden gradient flow structure in the dislocation dynamics. The model is derived as…

Numerical Analysis · Mathematics 2016-01-12 Vladimir Chalupecky , Masato Kimura

We study smectic liquid crystals in random environments, e.g., aerogel. A low temperature analysis reveals that even arbitrarily weak quenched disorder (i.e., arbitrarily low aerogel density) destroys translational (smectic) order. A…

Soft Condensed Matter · Physics 2009-10-31 Leo Radzihovsky , John Toner

Dislocations are ubiquitous in three-dimensional solid-state materials. The interplay of such real space topology with the emergent band topology defined in reciprocal space gives rise to gapless helical modes bound to the line defects.…

Mesoscale and Nanoscale Physics · Physics 2022-03-02 Liping Ye , Chunyin Qiu , Meng Xiao , Tianzi Li , Juan Du , Manzhu Ke , Zhengyou Liu

The gradient flow structure of the model introduced in [CG99] for the dynamics of screw dislocations is investigated by means of a generalised minimising-movements scheme approach. The assumption of a finite number of available glide…

Dynamical Systems · Mathematics 2016-03-01 Giovanni A. Bonaschi , Patrick van Meurs , Marco Morandotti