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In this paper we show the emergence of polycrystalline structures as a result of elastic energy minimisation. For this purpose, we introduce a variational model for two-dimensional systems of edge dislocations, within the so-called core…

Analysis of PDEs · Mathematics 2023-04-26 Silvio Fanzon , Mariapia Palombaro , Marcello Ponsiglione

Scale-space energy density function, $E(\mathbf{x}, \mathbf{r})$, is defined as the derivative of the two-point velocity correlation. The function E describes the turbulent kinetic energy density of scale r at a location x and can be…

Fluid Dynamics · Physics 2021-07-07 S. Arun , A. Sameen , Balaji Srinivasan , Sharath S. Girimaji

In this paper, starting from the microscopic dynamics of isolated dislocations, we explain how to derive formally mean field models for the dynamics of dislocation densities. Essentially these models are tranport equations, coupled with the…

Mathematical Physics · Physics 2009-01-16 Ahmad El Hajj , H. Ibrahim , Régis Monneau

Understanding the spontaneous emergence of dislocation patterns during plastic deformation is a long standing challenge in dislocation theory. During the past decades several phenomenological continuum models of dislocation patterning were…

Materials Science · Physics 2016-06-22 Istvan Groma , Michael Zaiser , Peter Dusan Ispanovity

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

Elastic flow for closed curves can involve significant deformations. Mesh-based approximation schemes require tangentially redistributing vertices for long-time computations. We present and analyze a method that uses the Dirichlet energy…

Numerical Analysis · Mathematics 2022-05-09 Paola Pozzi , Björn Stinner

By introducing the self-energy density functionals for the dissipative interactions between the reduced system and its environment, we develop a time-dependent density-functional theory formalism based on an equation of motion for the…

Quantum Physics · Physics 2009-11-13 Xiao Zheng , Fan Wang , Chi Yung Yam , Yan Mo , GuanHua Chen

Discrete dislocation dynamics (DDD) simulations offer valuable insights into the plastic deformation and work-hardening behavior of metals by explicitly modeling the evolution of dislocation lines under stress. However, the computational…

Materials Science · Physics 2023-08-22 Rasool Ahmad , Wei Cai

Standard approximations for the exchange-correlation functional are known to deviate from linear dependence of the energy on the electron and spin numbers (in -space). Violation of this flat-plane condition underlies the failure of all…

Classical Physics · Physics 2013-10-28 Ali M. Malek , Robert Balawender

We study a continuum model of dislocation transport in order to investigate the formation of heterogeneous dislocation patterns. We propose a physical mechanism which relates the formation of heterogeneous patterns to the dynamics of a…

Materials Science · Physics 2018-08-29 Ronghai Wu , Daniel Tüzes , Péter Dusán Ispánovity , István Groma , Michael Zaiser

We develop an approximation scheme for three-dimensional dislocation dynamics in which the dislocation line density is concentrated at points, or monopoles. Every monopole carries a Burgers vector and an element of line. The monopoles move…

Computational Physics · Physics 2018-11-14 A. Deffo , M. P. Ariza , M. Ortiz

We propose and analyze a simple variational model for dislocations at semi-coherent interfaces. The energy functional describes the competition between two terms: a surface energy induced by dislocations that compensate the lattice misfit…

Analysis of PDEs · Mathematics 2019-02-19 Silvio Fanzon , Mariapia Palombaro , Marcello Ponsiglione

The plasticity transition at the yield strength of a crystal typically signifies the tendency of dislocation defects towards relatively unrestricted motion. For an isolated dislocation the motion is in the slip plane with velocity…

Materials Science · Physics 2020-01-15 Péter Dusán Ispánovity , Stefanos Papanikolaou , István Groma

A density functional theory for a macroion suspension is examined, where the excess free energy corresponds to the macroion self energy arising from the polarisation of the supporting electrolyte solution. This is treated within a…

Soft Condensed Matter · Physics 2007-05-23 Patrick B. Warren

The fundamental interactions between an edge dislocation and a random solid solution are studied by analyzing dislocation line roughness profiles obtained from molecular dynamics simulations of Fe0.70Ni0.11 Cr0.19 over a range of stresses…

The Discrete elastic rod method (Bergou et al., 2008) is a numerical method for simulating slender elastic bodies. It works by representing the center-line as a polygonal chain, attaching two perpendicular directors to each segment, and…

Soft Condensed Matter · Physics 2021-12-22 Kevin Korner , Basile Audoly , Kaushik Bhattacharya

We study strain-controlled plastic deformation of crystalline solids via two-dimensional discrete dislocation dynamics simulations. To this end, we characterize the average stress-strain curves as well as the statistical properties of…

Materials Science · Physics 2021-09-01 David Kurunczi-Papp , Lasse Laurson

The importance of accurate simulation of the plastic deformation of ductile metals to the design of structures and components is well-known. Many techniques exist that address the length scales relevant to deformation pro- cesses, including…

Materials Science · Physics 2016-08-16 Reese Jones , Jonathan Zimmerman , Giacomo Po

It has been shown in experiments that self-climb of prismatic dislocation loops by pipe diffusion plays important roles in their dynamical behaviors, e.g., coarsening of prismatic loops upon annealing, as well as the physical and mechanical…

Materials Science · Physics 2019-05-21 Xiaohua Niu , Yejun Gu , Yang Xiang

From a simplified version of the mathematical structure of the strong coupling limit of the exact exchange-correlation functional, we construct an approximation for the electronic repulsion energy at physical coupling strength, which is…

Chemical Physics · Physics 2017-05-11 Stefan Vuckovic , Paola Gori-Giorgi