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Related papers: Dislocation drag and its influence on elastic prec…

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Hydrogen embrittlement (HE) poses a significant challenge to the durability of materials used in hydrogen production and utilization. Disentangling the competing nanoscale mechanisms driving HE often relies on simulations and…

The statistical-thermodynamic dislocation theory developed in previous papers is used here in an analysis of high-temperature deformation of aluminum and steel. Using physics-based parameters that we expect theoretically to be independent…

Materials Science · Physics 2017-07-19 K. C. Le , T. M. Tran , J. S. Langer

Crystal plasticity theory is often employed to predict the mesoscopic states of polycrystalline metals, and is well-known to be costly to simulate. Using a neural network with convolutional layers encoding correlations in time and space, we…

Computational Physics · Physics 2019-10-09 Ari Frankel , Kousuke Tachida , Reese Jones

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

In this study, we present the first simulation results of the formation of dislocation cell wall microstructures in tantalum subjected to shock loading. Dislocation patterns and cell wall formation are important to understanding the…

Materials Science · Physics 2023-05-04 Jaehyun Cho , Luke L. Hsiung , Robert E. Rudd , Sylvie Aubry

It is well known that diamond does not deform plastically at room temperature and usually fails in catastrophic brittle fracture. Here we demonstrate room-temperature dislocation plasticity in sub-micrometer sized diamond pillars by in-situ…

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

A correlation is established between the macro-scale friction regimes of metals and a transition between two dominant atomistic mechanisms of deformation. Metals tend to exhibit bi-stable friction behavior -- low and converging or high and…

Materials Science · Physics 2018-05-23 Nicolas Argibay , Michael E. Chandross , Shengfeng Cheng , Joseph R. Michael

In small-scale metallic systems, collective dislocation activity has been correlated with size effects in strength and with a step-like plastic response under uniaxial compression and tension. Yielding and plastic flow in these samples is…

Materials Science · Physics 2019-07-18 Xiaoyue Ni , Stefanos Papanikolaou , Gabriele Vajente , Rana X Adhikari , Julia R. Greer

Strain hardening is a key feature observed in many rocks deformed in the so-called ``semi-brittle'' regime, where both crystal plastic and brittle deformation mechanisms operate. Dislocation storage has long been recognised as a major…

Geophysics · Physics 2025-02-14 Nicolas Brantut

A physically-informed continuum crystal plasticity model is presented to elucidate the deformation mechanisms and dislocation evolution in body-centered-cubic (bcc) tantalum widely used as a key structural material for mechanical and…

We reformulate the theory of polycrystalline plasticity, in externally driven, nonequilibrium situations, by writing equations of motion for the flow of energy and entropy associated with dislocations. Within this general framework, and…

Materials Science · Physics 2010-01-21 J. S. Langer , Eran Bouchbinder , Turab Lookman

Atomistic simulations are performed to probe the anisotropic deformation in the compressions of face-centred-cubic metallic nanoparticles. In the elastic regime, the compressive load-depth behaviors can be characterized by the classical…

Materials Science · Physics 2018-10-29 Jianjun Bian , Hao Zhang , Xinrui Niu , Gangfeng Wang

Viscoplastic flow of polycrystalline metallic materials is the result of motion and interaction of dislocations, line defects of the crystalline structure. In the microstructural (physics-based) constitutive model presented in this paper,…

Materials Science · Physics 2018-09-11 S. Amir H. Motaman , Ulrich Prahl

Predicting the process of porosity-based ductile damage in polycrystalline metallic materials is an essential practical topic. Ductile damage and its precursors are represented by extreme values in stress and material state quantities, the…

Materials Science · Physics 2023-08-09 Yinling Zhang , Nan Chen , Curt A. Bronkhorst , Hansohl Cho , Robert Argus

The yield surface in crystal plasticity can be approached from various directions during mechanical loading. We consider the competition between nanoindentation and tensile loading towards plastic yielding. For this purpose, we develop a…

Materials Science · Physics 2017-07-14 Hengxu Song , Hakan Yavas , Erik Van der Giessen , Stefanos Papanikolaou

Plastic deformation mediated by collective dislocation dynamics is investigated in the two-dimensional phase-field crystal model of sheared single crystals. We find that intermittent fluctuations in the dislocation population number…

Materials Science · Physics 2015-01-05 Jens M. Tarp , Luiza Angheluta , Joachim Mathiesen , Nigel Goldenfeld

We use computer simulations to study the behavior of atomically sharp and blunted cracks in various f.c.c. metals. The simulations use effective medium potentials which contain many-body interactions. We find that when using potentials…

Materials Science · Physics 2007-05-23 J. Schiotz , A. E. Carlsson

Plastic response due to dislocation activity under intense electric fields is proposed as a source of breakdown. A model is formulated based on stochastic multiplication and arrest under the stress generated by the field. A critical…

Plasma Physics · Physics 2018-03-28 Eliyahu Zvi Engelberg , Yinon Ashkenazy , Michael Assaf

Research in the field of Materials Science and Engineering focuses on the design, synthesis, properties, and performance of materials. An important class of materials that is widely investigated are crystalline materials, including metals…

Materials Science · Physics 2023-09-14 Ahmad Zainul Ihsan , Said Fathalla , Stefan Sandfeld