95 citations · 599 across the 28 of their papers we have counts for
24 papers · 1 filter
Variational approach to determine the properties of dislocations at finite deformation
István Groma
A generalised version of the continuum theory of curved dislocations describing the spatial and temporal evolution of the fields: statistically stored dislocation density, geometri…
Dislocation distribution near a wall within the framework of the continuum theory of curved dislocations
István Groma, Dénes Berta, Lóránt Sándli +1
A recently proposed generalised continuum theory of curved dislocations describes the spatial and temporal evolution of statistically stored and geometrically necessary dislocation…
Irreversible evolution of dislocation pile-ups during cyclic microcantilever bending
Dávid Ugi, Kolja Zoller, Kolos Lukács +5
In metals geometrically necessary dislocations (GNDs) are generated primarily to accommodate strain gradients and they play a key role in the Bauschinger effect, strain hardening,…
Statistical analysis of dislocation cells in uniaxially deformed copper single crystals
Sándor Lipcsei, Szilvia Kalácska, Péter Dusán Ispánovity +3
The dislocation microstructure developing during plastic deformation strongly influences the stress-strain properties of crystalline materials. The novel method of high resolution…
Irradiation-induced strain localization and strain burst suppression investigated by microcompression and concurrent acoustic emission experiments
Dávid Ugi, Gábor Péterffy, Sándor Lipcsei +4
Plastic deformation of microsamples is characterised by large intermittent strain bursts caused by dislocation avalanches. Here we investigate how ion irradiation affects this phen…
Dislocation Avalanches: Earthquakes on the Micron Scale
Péter Dusán Ispánovity, Dávid Ugi, Gábor Péterffy +7
Compression experiments on micron-scale specimens and acoustic emission (AE) measurements on bulk samples revealed that the dislocation motion resembles a stick-slip process - a se…
On the dynamics of curved dislocation ensembles
István Groma, Péter Dusán Ispánovity, Thomas Hochrainer
To develop a dislocation-based statistical continuum theory of crystal plasticity is a major challenge of materials science.During the last two decades such a theory has been devel…
Efficient numerical method to handle boundary conditions in 2D elastic media
Denes Berta, Istvan Groma, Peter Dusan Ispanovity
A numerical method is developed to efficiently calculate the stress (and displacement) field in finite 2D rectangular media. The solution is expanded on a function basis with eleme…
Deterministic and stochastic models of dislocation patterning
Ronghai Wu, Daniel Tüzes, Péter Dusán Ispánovity +2
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 f…
The Emergence and Role of Dipolar Dislocation Patterns in Discrete and Continuum Formulations of Plasticity
Péter Dusán Ispánovity, Stefanos Papanikolaou, István Groma
The plasticity transition at the yield strength of a crystal typically signifies the tendency of dislocation defects towards relatively unrestricted motion. For an isolated disloca…
Comparison of the dislocation density obtained by HR-EBSD and X-ray profile analysis
Szilvia Kalácska, István Groma, András Borbély +1
Based on the cross correlation analysis of the Kikuchi diffraction patterns high-resolution EBSD is a well established method to determine the internal stress in deformed crystalli…
The role of weakest links and system size scaling in multiscale modeling of stochastic plasticity
Péter Dusán Ispánovity, Dániel Tüzes, Péter Szabó +2
Plastic deformation of crystalline and amorphous matter often involves intermittent local strain burst events. To understand the physical background of the phenomenon a minimal sto…
Micron-scale deformation: a coupled in-situ study of strain bursts and acoustic emission
Ádám István Hegyi, Péter Dusán Ispánovity, Michal Knapek +6
Plastic deformation of micron-scale crystalline materials differ considerably from bulk ones, because it is characterized by random strain bursts. To obtain a detailed picture abou…
Dislocation patterning in a 2D continuum theory of dislocations
Istvan Groma, Michael Zaiser, Peter Dusan Ispanovity
Understanding the spontaneous emergence of dislocation patterns during plastic deformation is a long standing challenge in dislocation theory. During the past decades several pheno…
Plastic strain is a mixture of avalanches and quasi-reversible deformations: Study of various sizes
Peter Szabo, Peter Dusan Ispanovity, Istvan Groma
Size-dependence of plastic flow is studied by discrete dislocation dynamical simulation of systems with various numbers of interacting linear edge dislocations while the stress is…
Scale-free phase field theory of dislocations
Istvan Groma, Zoltan Vandrus, Peter Dusan Ispanovity
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 duri…
Avalanches in 2D Dislocation Systems: Plastic Yielding is not Depinning
Péter Dusán Ispánovity, Lasse Laurson, Michael Zaiser +3
We study the properties of strain bursts (dislocation avalanches) occurring in two-dimensional discrete dislocation dynamics models under quasistatic stress-controlled loading. Con…
Average yielding and weakest link statistics in micron-scale plasticity
Péter Dusán Ispánovity, Ádám Hegyi, István Groma +3
Micron-scale single crystalline materials deform plastically via large intermittent strain bursts that make the deformation process unpredictable. Here we investigate this stochast…
Some Limitations of Dislocation Walls as Models for Plastic Boundary Layers
Michael Zaiser, Istvan Groma
It has recently become popular to analyze the behavior of excess dislocations in plastic deformation under the assumption that such dislocations are arranged into walls with period…
Criticality of relaxation in dislocation systems
Péter Dusán Ispánovity, István Groma, Géza Györgyi +2
Relaxation processes of dislocation systems are studied by two-dimensional dynamical simulations. In order to capture generic features, three physically different scenarios were st…
Abnormal subgrain growth in a dislocation-based model of recovery
Péter Dusán Ispánovity, István Groma, Wolfgang Hoffelner +1
Simulation of subgrain growth during recovery is carried out using two-dimensional discrete dislocation dynamics on a hexagonal crystal lattice having three symmetric slip planes.…
Submicron plasticity: yield stress, dislocation avalanches, and velocity distribution
Péter Dusán Ispánovity, István Groma, Géza Györgyi +2
The existence of a well defined yield stress, where a macroscopic piece of crystal begins to plastically flow, has been one of the basic observations of materials science. In contr…
On the range of 3D dislocation pair correlations
Ferenc F. Csikor, István Groma, Thomas Hochrainer +2
Numerical studies of dislocation pair correlations have played a central role in deriving a continuum theory from the equations of motion of 2D dislocation systems in a mathematica…
Role of density fluctuations in the relaxation of random dislocation systems
Ferenc F. Csikor, Michael Zaiser, Péter Dusán Ispánovity +1
We study the relaxation dynamics of systems of straight, parallel crystal dislocations, starting from initially random and uncorrelated positions of the individual dislocations. A…