A composite dislocation cell model to describe strain path change effects in BCC metals

Yalçınkaya, Tuncay
Geers, M.G.D.
Sheet metal forming processes are within the core of many modern manufacturing technologies, as applied in, e.g., automotive and packaging industries. Initially flat sheet material is forced to transform plastically into a three-dimensional shape through complex loading modes. Deviation from a proportional strain path is associated with hardening or softening of the material due to the induced plastic anisotropy resulting from the prior deformation. The main cause of these transient anisotropic effects at moderate strains is attributed to the evolving underlying dislocation microstructures. In this paper, a composite dislocation cell model, which explicitly describes the dislocation structure evolution, is combined with a BCC crystal plasticity framework to bridge the microstructure evolution and its macroscopic anisotropic effects. Monotonic and multi-stage loading simulations are conducted for a single crystal and polycrystal BCC metal, and the obtained macroscopic results and dislocation substructure evolution are compared qualitatively with the published experimental observations.
Modelling and Simulation in Materials Science and Engineering


A mathematical model for the behavior of laminated glass beams
Aşık, Mehmet Zülfü (Elsevier BV, 2005-08-01)
Two-ply laminated architectural glass used in automotive industry since 1914, now become an important element in construction industry as well. Regarding its importance, a theoretical model is needed for the laminated glass beams investigated mostly experimentally so far. In this paper, a mathematical model for the behavior of laminated glass beams is introduced. The minimum total potential energy principle is employed in developing the mathematical model by assuming large deflection for a laminated composi...
A new formulation for the analysis of elastic layers bonded to rigid surfaces
Pinarbasi, Seval; Akyüz, Uğurhan; Mengi, Yalcin (Elsevier BV, 2006-07-01)
Elastic layers bonded to rigid surfaces have widely been used in many engineering applications. It is commonly accepted that while the bonded surfaces slightly influence the shear behavior of the layer, they can cause drastic changes on its compressive and bending behavior. Most of the earlier studies on this subject have been based on assumed displacement fields with assumed stress distributions, which usually lead to "average" solutions. These assumptions have somehow hindered the comprehensive study of s...
A Novel Acetylcholinesterase Biosensor: Core-Shell Magnetic Nanoparticles Incorporating a Conjugated Polymer for the Detection of Organophosphorus Pesticides
Cancar, Hurija Dzudzevic; SÖYLEMEZ, Saniye; AKPINAR, Yeliz; KESİK, Melis; Goker, SEZA; Günbaş, Emrullah Görkem; Volkan, Mürvet; Toppare, Levent Kamil (American Chemical Society (ACS), 2016-03-30)
To construct a sensing interface, in the present work, a conjugated polymer and core shell magnetic nano particle containing biosensor was constructed for the pesticide analysis. The monomer 4,7-di(furan-2-yl)benzo [c] [1,2,5]-thiadiazole (FBThF) and core shell magnetic nanoparticles were designed and synthesized for fabrication of the biosensing device. The magnetic nanoparticles were first treated with silica and then modified using carboxyl groups, which enabled binding of the biomolecules covalently. Fo...
A study of phase stability and mechanical properties of hydroxylapatite-nanosize alpha-alumina composites
Evis, Zafer (Elsevier BV, 2007-04-01)
Hydroxylapatite (HA)-nanosize alumina composites were synthesized to study their phase stability and mechanical properties. To make these composites, nanosize alpha-Al2O3 powder was used because of its better sinterability and densification as compared to nanosize gamma-Al2O3. The composites were air sintered without pressure and hot pressed in vacuum at 1100 degrees C and 1200 degrees C. In the composites, HA decomposed to tricalcium phosphate faster after the air sintering than hot pressing. Moreover, hex...
A constitutive model of nanocrystalline metals based on competing grain boundary and grain interior deformation mechanisms
Gürses, Ercan (Elsevier BV, 2011-12-01)
In this work, a viscoplastic constitutive model for nanocrystalline metals is presented. The model is based on competing grain boundary and grain interior deformation mechanisms. In particular, inelastic deformations caused by grain boundary diffusion, grain boundary sliding and dislocation activities are considered. Effects of pressure on the grain boundary diffusion and sliding mechanisms are taken into account. Furthermore, the influence of grain size distribution on macroscopic response is studied. The ...
Citation Formats
T. Yalçınkaya and M. G. D. Geers, “A composite dislocation cell model to describe strain path change effects in BCC metals,” Modelling and Simulation in Materials Science and Engineering, pp. 0–0, 2009, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/35658.