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Plasticity is governed by the evolution of, in general anisotropic, systems of dislocations. We seek to faithfully represent this evolution in terms of density-like variables which average over the discrete dislocation microstructure.…

Materials Science · Physics 2016-09-21 Mehran Monavari , Stefan Sandfeld , Michael Zaiser

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 present a new framework to quantify the effect of hydrogen on dislocations using large scale three-dimensional (3D) discrete dislocation dynamics (DDD) simulations. In this model, the first order elastic interaction energy associated…

Materials Science · Physics 2018-01-31 Yejun Gu , Jaafar A. El-Awady

The deep energy method (DEM) has been used to solve the elastic deformation of structures with linear elasticity, hyperelasticity, and strain-gradient elasticity material models based on the principle of minimum potential energy. In this…

Computational Engineering, Finance, and Science · Computer Science 2023-01-26 Junyan He , Diab Abueidda , Rashid Abu Al-Rub , Seid Koric , Iwona Jasiuk

A three-dimensional continuum dislocation theory for single crystals containing curved dislocations is proposed. A set of governing equations and boundary conditions is derived for the true placement, plastic slips, and loop functions in…

Materials Science · Physics 2015-06-12 Khanh Chau Le

Density functional theory can be extended to excited states by means of a unified variational approach for passive state ensembles. This extension overcomes the restriction of the typical density functional approach to ground states, and…

Chemical Physics · Physics 2019-07-10 Tim Gould , Stefano Pittalis

Over the past decades, discrete dislocation dynamics simulations have been shown to reliably predict the evolution of dislocation microstructures for micrometer-sized metallic samples. Such simulations provide insight into the governing…

Dislocation climb plays an important role in understanding plastic deformation of metallic materials at high temperature. In this paper, we present a continuum formulation for dislocation climb velocity based on densities of dislocations.…

Materials Science · Physics 2023-08-15 Chutian Huang , Shuyang Dai , Xiaohua Niu , Tianpeng Jiang , Zhijian Yang , Yejun Gu , Yang Xiang

In the current density functional theory of linear and nonlinear time-dependent phenomena, the treatment of exchange and correlation beyond the level of the adiabatic local density approximation is shown to lead to the appearance of…

Condensed Matter · Physics 2009-10-30 G. Vignale , C. A. Ullrich , S. Conti

A phase field model is presented to investigate dislocation formation (coherency loss) and workhardening in two-phase binary alloys. In our model the elastic energy density is a periodic function of the shear and tetragonal strains, which…

Statistical Mechanics · Physics 2013-05-29 Akihiko Minami , Akira Onuki

The packing of elastic sheets is investigated in a quasi two-dimensional experimental setup: a sheet is pulled through a rigid hole acting as a container, so that its configuration is mostly prescribed by the cross-section of the sheet in…

Classical Physics · Physics 2009-11-13 Stephanie Deboeuf , Mokhtar Adda-Bedia , Arezki Boudaoud

The review is devoted to the theory of collective and it local pinning effects in various disordered non-linear driven systems. Although the emphasis is put on charge and spin density waves and magnetic domain walls, the theory has also…

Statistical Mechanics · Physics 2009-11-10 Serguei Brazovskii , Thomas Nattermann

This work explores the use of joint density-functional theory, a new form of density-functional theory for the ab initio description of electronic systems in thermodynamic equilibrium with a liquid environment, to describe electrochemical…

Materials Science · Physics 2015-06-05 Kendra Letchworth-Weaver , T. A. Arias

A new energy-consistent discretization of the viscous dissipation function in incompressible flows is proposed. It is implied by choosing a discretization of the diffusive terms and a discretization of the local kinetic energy equation and…

Fluid Dynamics · Physics 2023-07-21 Benjamin Sanderse , Francesc Xavier Trias

A phenomenological model of the evolution of an ensemble of interacting dislocations in an isotropic elastic medium is formulated. The line-defect microstructure is described in terms of a spatially coarse-grained order parameter, the…

mtrl-th · Physics 2009-10-30 J. M. Rickman , Jorge Vinals

In this paper we study the twist disclination within the elastoplastic defect theory. Using the stress function method, we found exact analytical solutions for all characteristic fields of a straight twist disclination in an infinitely…

Materials Science · Physics 2009-11-10 Markus Lazar

Previously, it has been shown that the direct correlation function for a Lennard-Jones fluid could be modeled by a sum of that for hard-spheres, a mean-field tail and a simple linear correction in the core region constructed so as to…

Statistical Mechanics · Physics 2008-08-20 James F. Lutsko

A computational approach has been developed for the analysis of the properties of 3D dislocation substructures generated by the vector density continuum dislocation dynamics (CDD), within the framework of crystal plasticity. In the CDD…

Integral expressions are determined for the elastic displacement and stress fields due to stationary or moving dislocation loops in three dimensional, not necessarily isotropic, finite samples. A line integral representation is found for…

Materials Science · Physics 2007-05-23 Rodrigo Arias , Fernando Lund

We propose a dynamic version of the three-dimensional translation gauge theory of dislocations. In our approach, we use the notions of the dislocation density and dislocation current tensors as translational field strengths and the…

Materials Science · Physics 2020-10-05 Markus Lazar