Constitutive Modeling of Nanocrystalline Metals based on Competing Grain Boundary and Grain Interior Deformation Mechanisms



Constitutive modeling of strain rate effects in nanocrystalline and ultrafine grained polycrystals
Gürses, Ercan (Elsevier BV, 2011-5)
We present a variational two-phase constitutive model capable of capturing the enhanced rate sensitivity in nanocrystalline (nc) and ultrafine-grained (ufg) fcc metals. The nc/ufg-material consists of a grain interior phase and a grain boundary affected zone (GBAZ). The behavior of the GBAZ is described by a rate-dependent isotropic porous plasticity model, whereas a rate-independent crystal-plasticity model which accounts for the transition from partial dislocation to full dislocation mediated plasticity i...
Constitutive modeling of stress-driven grain growth in nanocrystalline metals
Gürses, Ercan; El Sayed, Tamer (IOP Publishing, 2013-03-01)
In this work, we present a variational multiscale model for grain growth in face-centered cubic nanocrystalline (nc) metals. In particular, grain-growth-induced stress softening and the resulting relaxation phenomena are addressed. The behavior of the polycrystal is described by a conventional Taylor-type averaging scheme in which the grains are treated as two-phase composites consisting of a grain interior phase and a grain boundary-affected zone. Furthermore, a grain-growth law that captures the experimen...
Monte Carlo Analysis of Molecule Absorption Probabilities in Diffusion-Based Nanoscale Communication Systems with Multiple Receivers
ARIFLER, DOGU; Arifler, Dizem (2017-04-01)
For biomedical applications of nanonetworks, employing molecular communication for information transport is advantageous over nano-electromagnetic communication: molecular communication is potentially biocompatible and inherently energy-efficient. Recently, several studies have modeled receivers in diffusion-based molecular communication systems as "perfectly monitoring" or "perfectly absorbing" spheres based on idealized descriptions of chemoreception. In this paper, we focus on perfectly absorbing receive...
Perturbation analysis of sheath evolution, with application to plasma source ion implantation
Bektursunova, RM; Demokan, O (IOP Publishing, 2001-02-07)
A perturbation model has been developed to describe the evolution of an expanding plasma sheath around a cathode after a high-voltage negative pulse is applied to the cathode, simulating the conditions in devices such as those used for plasma source ion implantation. The set of governing equations consists of two coupled collisionless fluid equations for ions, and Poisson's equation and Boltzmann's assumption for electrons. The time-dependent, self-consistent expressions for the potential, ion density and i...
Monte Carlo simulations of radioactive waste embedded into polymer
Ozdemir, Tonguc; Usanmaz, Ali (Elsevier BV, 2009-09-01)
Radioactive waste is generated from the nuclear applications and it should properly be managed according to the regulations set by the regulatory authority. Poly(carbonate urethane) and poly (bisphenol a-co-epichlorohydrin) are radiation-resistant polymers and they are possible candidate materials that can be used in the radioactive waste management. In this study, maximum allowable waste activity that can be embedded into these polymers and dose rate distribution of the waste drum (containing waste and the...
Citation Formats
E. Gürses, “Constitutive Modeling of Nanocrystalline Metals based on Competing Grain Boundary and Grain Interior Deformation Mechanisms,” 2012, Accessed: 00, 2021. [Online]. Available: