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Related papers: Thermodynamic dislocation theory: Size effect in t…

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Microcrystals deform very differently from their macroscopic counterparts, displaying a size-dependent yield stress and intermittent plastic strain bursts. Here we demonstrate that size effects and strain bursts may be just two different…

Materials Science · Physics 2012-04-04 Valentina Beato , Michael Zaiser , Stefano Zapperi

We perform atomistic Monte Carlo simulations of bending a Lennard-Jones single crystal in two dimensions. Dislocations nucleate only at the free surface as there are no sources in the interior of the sample. When dislocations reach…

Materials Science · Physics 2009-11-11 N. Scott Weingarten , Robin L. B. Selinger

Dislocation motion in body centered cubic (bcc) metals displays a number of specific features that result in a strong temperature dependence of the flow stress, and in shear deformation asymmetries relative to the loading direction as well…

Materials Science · Physics 2016-08-05 Giacomo Po , Yinan Cui , David Rivera , David Cereceda , Tom D. Swinburne , Jaime Marian , Nasr Ghoniem

Small-scale mechanical behaviour shows significant departures from classical elastic-plastic theory. In a remarkable number of instances, the strength of a material appears to scale as the reciprocal square root of the smallest length…

Materials Science · Physics 2009-10-30 T. T. Zhu , B. Ehrler , X. D. Hou , A. J. Bushby , D. J. Dunstan

Several different versions of couple stress theory have appeared in the literature, including the indeterminate Mindlin-Tiersten-Koiter couple stress theory (MTK-CST), indeterminate symmetric modified couple stress theory (M-CST) and…

General Physics · Physics 2016-05-10 Ali R. Hadjesfandiari , Gary F. Dargush

Stressed dislocation pattern formation in crystal plasticity at finite deformation is demonstrated for the first time. Size effects are also demonstrated within the same mathematical model. The model involves two extra material parameters…

Materials Science · Physics 2018-12-04 Rajat Arora , Amit Acharya

It is a long-lasting task to understand heat conduction phenomena beyond Fourier. Besides the low-temperature experiments on extremely pure crystals, it has turned out recently that heterogeneous materials with macro-scale size can also…

Dislocations are the carriers of plasticity in crystalline materials. Their collective interaction behavior is dependent on the strain rate and sample size. In small specimens, details of the nucleation process are of particular importance.…

Materials Science · Physics 2020-11-05 Jianqiao Hu , Hengxu Song , Zhanli Liu , Zhuo Zhuang , Xiaoming Liu , Stefan Sandfeld

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

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

The films of order-disorder type ferroelectrics were considered in the mean field approximation taking into account depolarization field. It was shown that size effects in this system could be described on the base of bulk system equation…

Materials Science · Physics 2007-05-23 E. A. Eliseev , M. D. Glinchuk

Equations for dislocation evolution bridge the gap between dislocation properties and continuum descriptions of plastic behavior of crystalline materials. Computer simulations can help us verify these evolution equations and find their…

Materials Science · Physics 2020-11-11 Kamyar M. Davoudi , Joost J. Vlassak

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

We show here how density functional theory calculations can be used to predict the temperatureand orientation-dependence of the yield stress of body-centered cubic (BCC) metals in the thermallyactivated regime where plasticity is governed…

Materials Science · Physics 2021-05-10 Emmanuel Clouet , Baptiste Bienvenu , Lucile Dezerald , David Rodney

Plastic deformation in microscale differs from the macroscopic plasticity in two respects: (i) the flow stress of small samples depends on their size (ii) the scatter of plasticity increases significantly. In this work we focus on the…

Materials Science · Physics 2015-03-10 Olga Kapetanou , Vasilis Koutsos , Efstathios Theotokoglou , Daniel Weygand , Michael Zaiser

The impact of a two-dimensional elastic disk with a wall is numerically studied. It is clarified that the coefficient of restitution (COR) decreases with the impact velocity. The result is not consistent with the recent quasi-static theory…

Statistical Mechanics · Physics 2016-08-31 Hisao Hayakawa , Hiroto Kuninaka

The ability of a body-centered cubic metal to deform plastically is limited by the thermally activated glide motion of screw dislocations, which are line defects with a mobility exhibiting complex dependence on temperature, stress, and…

Materials Science · Physics 2020-11-25 M. Boleininger , M. Gallauer , S. L. Dudarev , T. D. Swinburne , D. R. Mason , D. Perez

This paper presents the thermodynamic dislocation theory containing several modifications over its first version which was originally proposed by Langer, Bouchbinder, and Lookman (2010). Employing a small set of physics-based material…

Materials Science · Physics 2020-07-13 Khanh Chau Le , Sa Ly Dang , Hoang Thien Luu , Nina Gunkelmann

Dislocation based modeling of plasticity is one of the central challenges at the crossover of materials science and continuum mechanics. Developing a continuum theory of dislocations requires the solution of two long standing problems: (i)…

Materials Science · Physics 2016-06-29 Thomas Hochrainer

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