One-dimensional magneto-mechanical model for anhysteretic magnetization and magnetostriction in ferromagnetic materials

Author(s):  
Pengpeng Shi
2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
C. Bertrand ◽  
A. Allou ◽  
F. Beauchamp ◽  
E. Pluyette ◽  
P. Defrasne ◽  
...  

The MECTUB code was developed to evaluate the risk of swelling and bursting of Steam Generator (SG) tubes. This code deals with the physic of intermediate steam-water leaks into sodium which induce a Sodium-Water Reaction (SWR). It is based on a one-dimensional calculation to describe the thermomechanical behavior of tubes under a high internal pressure and a fast external overheating. The mechanical model of MECTUB is strongly correlated with the kind of the material of the SG tubes. It has been developed and validated by using experiments performed on the alloy 800. A change to tubes made of Modified 9Cr-1Mo steel requires more knowledge of Modified 9Cr-1Mo steel behavior which influences the bursting time at high temperatures (up to 1200°C). Studies have been initiated to adapt the mechanical model and to qualify it for this material. The first part of this paper focuses on the mechanical law modelling (elasticity, plasticity, and creep) for Modified 9Cr-1Mo steel and on overheating thermal data. In a second part, the results of bursting tests performed on Modified 9Cr-1Mo tubes in the SQUAT facility of CEA are used to validate the mechanical model of MECTUB for the Modified 9Cr-1Mo material.


2011 ◽  
Vol 26 (16) ◽  
pp. 2735-2742 ◽  
Author(s):  
S.-H. HO

We investigate a one-dimensional quantum mechanical model, which is invariant under translations and dilations but does not respect the conventional conformal invariance. We describe the possibility of modifying the conventional conformal transformation such that a scale invariant theory is also invariant under this new conformal transformation.


2004 ◽  
Vol 15 (4) ◽  
pp. 451-486 ◽  
Author(s):  
CARLOS J. GARCÍA-CERVERA

Ferromagnetic materials may present a complicated domain structure, due in part to the nonlocal nature of the self interactions. In this article we present a detailed study of the structure of one-dimensional magnetic domain walls in uniaxial ferromagnetic materials, and in particular, of the Néel and Bloch walls. We analyze the logarithmic tail of the Néel wall, and identify the characteristic length scales in both the Néel and Bloch walls. This analysis is used to obtain the optimal energy scaling for the Néel and Bloch walls. Our results are illustrated with numerical simulations of one-dimensional walls. A new model for the study of ferromagnetic thin films is presented.


2019 ◽  
Vol 125 (23) ◽  
pp. 233901 ◽  
Author(s):  
Pengcheng Zhang ◽  
Pengpeng Shi ◽  
Ke Jin ◽  
Xiaojing Zheng

2014 ◽  
Vol 616 ◽  
pp. 14-18
Author(s):  
Kouichi Yasuda ◽  
Tadachika Nakayama ◽  
Satoshi Tanaka

A mechanical model is proposed to estimate internal stress during sintering of ceramic multiphase laminates. A symmetrical multi-layered laminate is assumed, and one-dimensional elastic analysis is carried out on the change in stress of each layer during sintering, based on the differences in sintering strain, thermal expansion strain and phase transformation strain between the layers. By taking a limit such that the thickness of each layer approaches infinitesimally small, the internal stress expression can be extended into the case of the materials with continuous compositional change (viz. functionally gradient materials).


2007 ◽  
Vol 22 (37) ◽  
pp. 2791-2797
Author(s):  
S. S. AFONIN

A one-dimensional quantum mechanical model possessing mass-gap, a gapless excitation, and an approximate parity doubling of energy levels is constructed based on heuristic QCD-inspired arguments. The model may serve for illustrative purposes when considering the related dynamical phenomena in particle and nuclear physics.


2001 ◽  
Vol 120 (1-3) ◽  
pp. 1009-1010
Author(s):  
A. Ardavan ◽  
J. Singleton ◽  
S.J. Blundell

Author(s):  
Hu Xiangyi ◽  
Bu Yang ◽  
Zhang Jianhua

Abstract As seen in the Jiles-Atherton (J-A) model and its modified form, the linear relationship between the magnetization coefficient and the stress deviates significantly from the experimental results. It is required to introduce many parameters that are difficult to obtain or unknown to describe the effect of elastoplastic deformation on magnetization or hysteresis, such as shape coefficient, pinning coefficient, and molecular field coefficient. In this paper, a new nonlinear magneto-elastoplastic model for ferromagnetic materials is established based on the magneto-mechanical coupling effect, and both the sixth-order term of magnetization and the nonlinear equation of the magnetization coefficient are introduced into the magnetostriction equation. In the models established in this paper, the elastoplastic deformation equivalent magnetic field is introduced into the effective magnetic field, and the Frohlich-Kennelly equation is used to describe the anhysteretic magnetization. After comparing the prediction results of different models with the available experimental results, it is observed that the proposed model in this paper exhibits superior prediction ability for magnetostrictive strain, magnetization, and hysteresis phenomena under different stresses. This paper has also analyzed the mechanism of the effect of elasto-plastic loading and residual plastic deformation on the hysteresis in different models as well as the differences between them. The determination coefficient of the proposed model in this paper is closer to 1 that is better than the existing models, indicating that it has a better fitting effect and is of great significance to the development of quantitative nondestructive testing technology.


1966 ◽  
Vol 25 ◽  
pp. 46-48 ◽  
Author(s):  
M. Lecar

“Dynamical mixing”, i.e. relaxation of a stellar phase space distribution through interaction with the mean gravitational field, is numerically investigated for a one-dimensional self-gravitating stellar gas. Qualitative results are presented in the form of a motion picture of the flow of phase points (representing homogeneous slabs of stars) in two-dimensional phase space.


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