Authors: A.K. Semennikov, S.Yu. Karpov, M.S. Ramm, A.E. Romanov, Yuri N. Makarov
383
Authors: Tomotsugu Shimokawa, Toshiyasu Kinari, Sukenori Shintaku
Abstract: The interactions between edge dislocations and the grain boundary have been studied
by using quasicontinuum simulations. With an increase in the shear strain, dislocation pile-up is
created and local stress concentration occurs at the head of the pile-up. The relationship between
the stress concentration and the number of dislocations in the pile-up is discussed.
973
Authors: Thomas. H. Simm, Philip J. Withers, Tamás Ungár, J. Fonseca
Abstract: Uniaxial deformed fcc metal samples have been studied by diffraction peak profile analysis. A method that can explain changes in broadening of different peaks by use of a Taylor model has been investigated. It was found that the method qualitatively describes the changes in broadening in nickel and stainless steel samples. It is argued that the differences between predictions and measurements are a feature of how the different samples deform at the microstructural scale.
139
Authors: Xiao Chun Ma, Ji Hui Yin
Abstract: The thermal effect has pronounced influence on deformation behavior of materials at nanoscale due to small length scale. In current paper, shear deformation of single crystal copper is simulated by molecular dynamics simulation, and special attention is paid to the thermal effect on the deformation behavior of material and mechanical response. The result shows that the plastic deformation of material during shear deformation is dominated by dislocation activities. Both the yield strength and shear strength have strong dependence on temperature due to thermal effect.
155
Authors: Karri V. Mani Krishna, Prita Pant
Abstract: Dislocation Dynamics (DD) simulations are used to study the evolution of a pre-specified dislocation structure under applied stresses and imposed boundary conditions. These simulations can handle realistic dislocation densities ranging from 1010 to 1014 m-2, and hence can be used to model plastic deformation and strain hardening in metals. In this paper we introduce the basic concepts of DD simulations and then present results from simulations in thin copper films and in bulk zirconium. In both cases, the effect of orientation on deformation behaviour is investigated. For the thin film simulations, rigid boundary conditions are used at film-substrate and film-passivation interfaces leading to dislocation accumulation, while periodic boundaries are used for bulk grains of Zr. We show that there is a clear correlation between strain hardening rate and the rate of increase of dislocation density.
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