Micromagnetic simulations on the grain shape effect in Nd-Fe-B magnets

2016 ◽  
Vol 120 (3) ◽  
pp. 033903 ◽  
Author(s):  
Min Yi ◽  
Oliver Gutfleisch ◽  
Bai-Xiang Xu
Keyword(s):  
Grain Shape ◽  
Shape Effect ◽  
Micromagnetic Simulations

Grain Shape Effect and the Viscoplastic Parameter on the Evolution of Isotropic and Kinematic Hardening of Metallic Materials under Cyclic Loading

2019 ◽  
Vol 820 ◽  
pp. 48-59
Author(s):  
Abdelhamid Kerkour-El Miad ◽  
A. Kerour-El Miad ◽  
Redouane Kouddane
Keyword(s):  
Grain Shape ◽  
Kinematic Hardening ◽  
Inelastic Strain ◽  
System Level ◽  
Elastic Behavior ◽  
Isotropic Hardening ◽  
Shape Effect ◽  
Metallic Materials ◽  
Crystallographic Slip ◽  
Self Consistent

The main objective of this work is to study the grain shape effect (aspect ratio α = a / b) and the viscoplastic parameter γ on the evolution of the kinematic and isotropic hardening of FCC type metallic materials, under uniaxial cyclic Tension-Compression ‘‘TC’ and to interpret these results. These parameters of shape and viscoplastic were developed and introduced by Abdul-Latif and Radi, indeed in this study we use their model. Expressed within the framework of a self-consistent approach, the rate-dependent inelastic strain is examined at the crystallographic slip system level describing a constitutive model for FCC metallic polycrystals, whereas the elastic strain is determined at the granular level. Based on the Eshelby’s tensor, the elastic behavior is assumed to be compressible. For a polycrystalline structure, the grains deform plastically by crystallographic slip located at the most favorably oriented systems supporting a high resolved shear stress . The approach considers that the inclusion (grain) form is ellipsoidal of half axes defining by a, b and c such as a ≠b= c. Several numerical tests are carried out highlighting the role of shape and viscoplastic parameter on the evolution of kinematic and isotropic hardening. A general comparison between the and effect on the overall hardening of the polycrystal shows that this work hardening is more sensitive to the parameter (for given ) compared to (for given). Keywords: Grain shape effect, Ellipsoidal inclusion, Viscoplastic parameter effect, Kinematic and isotropic hardening, Uniaxial cyclic ‘‘TC‘‘, Self-consistent model.

Stress-chain based micromechanics of sand with grain shape effect

2010 ◽  
Vol 12 (5) ◽  
pp. 499-505 ◽  
Author(s):  
Kenichi Maeda ◽  
Hirotaka Sakai ◽  
Akihiko Kondo ◽  
Tomoyo Yamaguchi ◽  
Masatoshi Fukuma ◽  
...  
Keyword(s):  
Grain Shape ◽  
Shape Effect ◽  
Stress Chain

707 Evaluation of Grain Shape Effect on Tin Whisker Growth by Stress-Diffusion Analysis

2008 ◽  
Vol 2008.21 (0) ◽  
pp. 289-290
Author(s):  
T. Suzuki ◽  
Y. Okura ◽  
T. Terasaki ◽  
T. Iwasaki ◽  
T. Kato ◽  
...  
Keyword(s):  
Whisker Growth ◽  
Grain Shape ◽  
Shape Effect ◽  
Tin Whisker ◽  
Diffusion Analysis ◽  
Stress Diffusion

Modeling of the Grain Shape Effect on the Elastic-Inelastic Behavior of Polycrystals With Self-Consistent Scheme

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
A. Abdul-Latif ◽  
M. Radi
Keyword(s):  
Grain Shape ◽  
Spherical Inclusion ◽  
Shape Effect ◽  
Inelastic Behavior ◽  
Consistent Model ◽  
Self Consistent ◽  
Eshelby’S Tensor ◽  
Anisotropic Elastic ◽  
Nonlinear Elastic ◽  
Interaction Law

Based on a well established nonincremental interaction law for fully anisotropic elastic-inelastic behavior of polycrystals, tangent formulation-based and simplified interaction laws of softened nature are derived to describe the nonlinear elastic-inelastic behavior of fcc polycrystals. Using the Eshelby’s tensor, the developed approach considers that the inclusion (grain) form is ellipsoidal. It has been clearly demonstrated by Abdul-Latif et al. (2002, “Elastic-Inelastic Self-Consistent Model for Polycrystals,” ASME J. Appl. Mech., 69, pp. 309–316) for spherical inclusion that the tangent formulation-based model requires more calculation time, and is incapable to describe correctly the multiaxial elastic-inelastic behavior of polycrystals in comparison with the simplified model. Hence, the simplified nonincremental interaction is studied considering the grain shape effect. A parametric study is conducted showing principally the influence of the some important parameters (the grain shape (α) and the new viscous parameter γ) and the effect of their interaction on the hardening evolution of polycrystals. Quantitatively, it is recognized that the model describes suitably the grain shape effect together with the new viscous parameter γ on the strain-stress behavior of aluminum and Waspaloy under tensile test.

Grain shape effect on the anisotropic behaviour of silt–sand mixtures

2014 ◽  
Vol 167 (3) ◽  
pp. 281-296 ◽  
Author(s):  
Navid Khayat ◽  
Abbas Ghalandarzadeh ◽  
Mohammad Kazem Jafari
Keyword(s):  
Grain Shape ◽  
Shape Effect ◽  
Anisotropic Behaviour

Modeling of Grain Shape Effect on Multiaxial Plasticity of Metallic Polycrystals

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
A. Abdul-Latif
Keyword(s):  
Grain Shape ◽  
Inelastic Strain ◽  
Cyclic Behavior ◽  
Loading Path ◽  
Model Parameters ◽  
Shape Effect ◽  
Inelastic Behavior ◽  
Aspect Ratios ◽  
Ellipsoidal Shape ◽  
Aluminum Alloy 2024

A simplified nonincremental interaction law is used describing the nonlinear elastic-inelastic behavior of FCC polycrystals proposed recently (Abdul-Latif and Radi, 2010, “Modeling of the Grain Shape Effect on the Elastic-Inelastic Behavior of Polycrystals with Self-Consistent Scheme,” ASME J. Eng. Mater. Technol., 132(1), p. 011008). In this scheme, the elastic strain defined at the granular level based on the Eshelby's tensor is assumed to be isotropic, uniform and compressible. Hence, the approach considers that the inclusion (grain) has an ellipsoidal shape of half axes defining by a, b and c such as a ≠ b = c. The granular heterogeneous inelastic strain is locally determined using the slip theory. Both elastic and inelastic granular strains depend on the granular aspect ratio (α = a/b). An aggregate of grains of ellipsoidal shape is supposed to be randomly distributed with a distribution of aspect ratios having a log-normal statistical function. The effect of this distribution on the mechanical behavior is investigated. A host of cyclic inelastic behavior of polycrystalline metals is predicted under uniaxial and multiaxial loading paths. Using the aluminum alloy 2024, an original complex cyclic loading path type is proposed and carried out experimentally. After the model parameters calibration, the elastic-inelastic cyclic behavior of this alloy is quantitatively described by the model. As a conclusion, the model can successfully describe the elasto-inelastic at the overall and local levels.

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