Study of dislocation-twin boundary interaction mechanisms in plastic deformation of TWIP steel by discrete dislocation dynamics and dislocation density-based modelling

In this paper, three dimensional discrete dislocation dynamics method was used to quantitatively investigate the influence of initial defects on mechanical response of single crystal copper. Both the irradiation defects (interstitial loops) and random dislocation lines with different densities are considered. The simulation results demonstrate that the yield strength of single crystal copper is higher with higher initial dislocation density and higher interstitial loop density. Dislocation density increases quickly by nucleation and multiplication and microbands are formed during plastic deformation when only the random dislocation lines are initially considered. Characteristics of microbands show excellent agreement with experiment results. Dislocation multiplication is suppressed in the presence of interstitial loops, and junctions and locks between dislocations and interstitial loops are formed. Dislocation density evolution shows fluctuation accompanied with strain-stress curve fluctuation.

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Discrete Dislocation Dynamics Analysis of Cyclic Plastic Deformation near Growing Fatigue Crack Tip

The Proceedings of The Computational Mechanics Conference ◽

10.1299/jsmecmd.2002.15.141 ◽

2002 ◽

Vol 2002.15 (0) ◽

pp. 141-142

Author(s):

Yasuko MOTOYASHIKI ◽

Atsushi SUGETA ◽

Yoshihiko UEMATSU ◽

Masahiro JONO

Keyword(s):

Plastic Deformation ◽

Fatigue Crack ◽

Crack Tip ◽

Dislocation Dynamics ◽

Dynamics Analysis ◽

Cyclic Plastic ◽

Discrete Dislocation Dynamics ◽

Discrete Dislocation ◽

Cyclic Plastic Deformation

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A study of the submicron indent-induced plastic deformation

Journal of Materials Research ◽

10.1557/jmr.1999.0301 ◽

1999 ◽

Vol 14 (6) ◽

pp. 2251-2258 ◽

Cited By ~ 37

Author(s):

C. F. Robertson ◽

M. C. Fivel

Keyword(s):

Plastic Deformation ◽

Three Dimensional ◽

Dislocation Nucleation ◽

Dislocation Dynamics ◽

Dynamics Simulation ◽

Nanoindentation Test ◽

Experimental Conditions ◽

Discrete Dislocation Dynamics ◽

Discrete Dislocation ◽

Transmission Electron

A new method has been developed to achieve a better understanding of submicron indent-induced plastic deformation. This method combines numerical modeling and various experimental data and techniques. Three-dimensional discrete dislocation dynamics simulation and the finite element method (FEM) were used to model the experimental conditions associated with nanoindentation testing in fcc crystals. Transmission electron microscopy (TEM) observations of the indent-induced plastic volume and analysis of the experimental loading curve help in defining a complete set of dislocation nucleation rules, including the shape of the nucleated loops and the corresponding macroscopic loading. A validation of the model is performed through direct comparisons between a simulation and experiments for a nanoindentation test on a [001] copper single crystal up to 50 nm deep.

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