Electromagnetic Nondestructive Testing Model and Surface Magnetic Field Analysis for Circumferential Cracks on Metal Rod

2019 ◽  
Vol 2 (4) ◽  
Author(s):  
Feng Jiang ◽  
Shulin Liu ◽  
Shaojie Xin ◽  
Hongli Zhang
Keyword(s):  
Magnetic Field ◽  
Analytical Model ◽  
Magnetic Induction ◽  
Crack Depth ◽  
Field Analysis ◽  
Surface Magnetic Field ◽  
Circumferential Crack ◽  
Inner Surface ◽  
Magnetic Induction Intensity ◽  
The Magnetic Field

Abstract In this paper, an analytical model for a metal rod with a coating layer is proposed to evaluate circumferential crack from the signals of the surface magnetic field. In the proposed model, magnetic vector equations for four regions of space were built, and series expressions of the magnetic field were proposed by the truncated region eigenfunction method. The calculation results can show the three-dimensional distribution of axial and radial magnetic induction intensities on the surface of a metal rod clearly. In addition, the analytical model is verified by using comsol finite element simulation, which also demonstrates that induced eddy currents on the inner surface of the metal rod with cracks appear to be propelled toward the inner layer of the metal rod and the presence of a circumferential crack directly causes a decrease in the induced eddy current on the inner surface of the rod. The results calculated from the analytical model indicated that the model is capable of providing an accurate variation in the magnetic field due to circumferential cracks at different depths. The analytical results showed that the radial magnetic induction intensity increases by 0.16 × 10−3 T, while the axial magnetic induction intensity decreases by 0.3 × 10−3 T as the crack depth increases from 0 to 3 mm.

The Magnetic Field Analysis of Dual-Coil Self-Sensing Actuator

2011 ◽  
Vol 181-182 ◽  
pp. 183-188 ◽  
Author(s):  
Cheng Wu Lin ◽  
Fang Dong ◽  
Hao Zheng ◽  
Hua Yan
Keyword(s):  
Magnetic Field ◽  
Magnetic Induction ◽  
Reference Value ◽  
Element Model ◽  
Field Analysis ◽  
Magnetic Field Analysis ◽  
Intensity Changes ◽  
Working Principle ◽  
Magnetic Induction Intensity ◽  
The Magnetic Field

This paper introduced working principle of dual-coil self-sensing actuator based on magnetically controlled shape memory alloy (MSMA). The ANSYS software was used to establish the finite element model of MSMA dual-coil self-sensing actuator. Edge element method was adopted to analyze the MSMA dual-coil self-sensing actuator's 3-D static magnetic field under the influence of different excitation voltages. The analysis obtained MSMA and silicon steel sheet distribution of magnetic induction intensity and the magnetic field intensity, has further confirmed the reliability of MSMA dual-coil self-sensing actuator, and has given the MSMA length relations along with the magnetic induction intensity changes. The results show that magnetic field analysis has certain reference value to the MSMA practical application.

Simulation Research on the Magnetic Field of the Positioning Permanent Magnet for MEMS inside Human Body Based on Ansoft

2014 ◽  
Vol 596 ◽  
pp. 67-71
Author(s):  
Xiu Quan Liu ◽  
Yan Hong Li
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Magnetic Dipole ◽  
Human Body ◽  
Magnetic Induction ◽  
Dipole Model ◽  
Magnetization Direction ◽  
Simulation Research ◽  
Magnetic Induction Intensity ◽  
The Magnetic Field

the magnetic dipole model of the cylindrical permanent magnet was introduced. Then, based on Ansoft software, the simulation model of the cylindrical permanent magnet was established, and the influence of some parameters, such as the height, radius and magnetization direction on the magnetic induction intensity ,were studied; at the same time, under these two models the calculation was compared, the result shows the the magnetic dipole model is applied on condition that distance is nine times greater than the cylindrical permanent magnet size.

scholarly journals Analysis of the Influence of Ferromagnetic Material on the Output Characteristics of Halbach Array Energy-Harvesting Structure

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1541
Author(s):  
Xiangyong Zhang ◽  
Haipeng Liu ◽  
Yunli He ◽  
Tingrui Peng ◽  
Bin Su ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Energy Harvesting ◽  
Magnetic Induction ◽  
Ferromagnetic Material ◽  
Magnetic Medium ◽  
Halbach Array ◽  
Harvesting Efficiency ◽  
Energy Harvesting Efficiency ◽  
Magnetic Induction Intensity ◽  
The Magnetic Field

Due to the particular arrangement of permanent magnets, a Halbach array has an significant effect of magnetism and magnetic self-shielding. It can stretch the magnetic lines on one side of the magnetic field to obtain an ideal sinusoidal unilateral magnetic field. It has a wide application range in the field of energy harvesting. In practical applications, magnetic induction intensity of each point in magnetic field is not only related to the induced current and conductor but also related to the permeability of the medium (also known as a magnetic medium) in the magnetic field. Permeability is the physical quantity that represents the magnetism of the magnetic medium, which indicates the resistance of magnetic flux or the ability of magnetic lines to be connected in the magnetic field after coil flows through current in space or in the core space. When the permeability is much greater than one, it is a ferromagnetic material. Adding a ferromagnetic material in a magnetic field can increase the magnetic induction intensity B. Iron sheet is a good magnetic material, and it is easy to magnetize to generate an additional magnetic field to strengthen the original magnetic field, and it is easy to obtain at low cost. In this paper, in order to explore the influence of ferromagnetic material on the magnetic field and energy harvesting efficiency of the Halbach array energy harvesting structure, iron sheets are installed on the periphery of the Halbach array rotor. Iron sheet has excellent magnetic permeability. Through simulation, angle between iron sheet and Halbach array, radian size of iron sheet itself and distance between iron sheet and Halbach array can all have different effects on the magnetic field of the Halbach array. It shows that adding iron sheets as a magnetic medium could indeed change the magnetic field distribution of the Halbach array and increase energy harvesting efficiency. In this paper, a Halbach array can be used to provide electrical power for passive wireless low-power devices.

scholarly journals Numerical Simulation on the Brake Effect of FAC-EMBr and EMBrRuler in the Continuous Casting Mold

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1620
Author(s):  
Zhuang Li ◽  
Lintao Zhang ◽  
Yanming Bao ◽  
Danzhu Ma
Keyword(s):  
Magnetic Field ◽  
Molten Steel ◽  
Casting Speed ◽  
Submerged Entry Nozzle ◽  
Pole Position ◽  
Level Fluctuation ◽  
Steel Flow ◽  
Magnetic Poles ◽  
Magnetic Induction Intensity ◽  
The Magnetic Field

The brake effect of the freestanding adjustable combination electromagnetic brake (FAC-EMBr) and EMBr ruler on the behavior of molten steel flow and the level fluctuation were investigated with the numerical method. The effects of the horizontal magnetic pole position (EMBr ruler), magnetic induction intensity, and casting speed on two types of electromagnetic brakes were studied. The numerical simulation results show that the magnetic field caused by the EMBr ruler is mainly distributed under the submerged entry nozzle (SEN), and it is very weak nearby the meniscus area. After the FAC-EMBr is applied, the magnetic field is mainly distributed in the area below the submerged entry nozzle, the upper roll region, and in the meniscus region. The application of the electromagnetic brake can effectively suppress the impact of the jet and decrease the molten steel velocity in the meniscus area. The brake effect of the EMBr ruler on the behavior of the molten steel flow and the level fluctuation is significantly influenced by the horizontal magnetic pole position. The increasing of the magnetic flux density can significantly increase the velocity of molten steel in the upper roll region and lead to an intense fluctuation in the steel/slag interface, as the horizontal magnetic field cannot cover the three key regions. The brake effect of the FAC-EMBr is less influenced by the variation of the process parameters due to the addition of vertical magnetic poles. Additionally, the “secondary braking effect” of the vertical magnetic poles can help to lower the increase of velocity in the upper roll region caused by the excessive magnetic induction intensity and the high casting speed. Therefore, even under the high casting speed conditions, the application of a new type of FAC-EMBr is also an efficient way to suppress the molten steel flow and level fluctuation at the meniscus area and decrease the possibility of slag entrapment.

2-D Magnetic Field Analysis of Air Cylinder with MR Sensor

2011 ◽  
Vol 121-126 ◽  
pp. 2706-2709
Author(s):  
Dan Jiang ◽  
Ping Yang ◽  
Kun Jiang
Keyword(s):  
Magnetic Field ◽  
Field Analysis ◽  
Magnetic Flux Density ◽  
Piston Motion ◽  
Element Analysis ◽  
Pneumatic Control ◽  
Magnetoresistive Sensor ◽  
Magnetic Field Analysis ◽  
Working Principle ◽  
The Magnetic Field

As a type of solid state switch, MR (magnetoresistive) sensor detects the air cylinder piston’s position in pneumatic control system. The construction and working principle of the air cylinder with MR sensor are introduced. Using 2-D magnetic field finite element analysis (FEA) method, the magnetic field distribution of air cylinder with piston motion is analyzed. Simulation results are given. The magnetic flux density characteristics are compared between piston wear or not.

The 3D Magnetic Field Analysis of Excitation Unit of Drill Pipe MFL Testing Based on ANSYS

2013 ◽  
Vol 694-697 ◽  
pp. 1179-1182
Author(s):  
Yi Lai Ma ◽  
Li Lin ◽  
Kai Wen Jiang ◽  
Xu Lin Zhao
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Drill Pipe ◽  
Magnetic Flux Leakage ◽  
Field Analysis ◽  
Ansys Software ◽  
Magnetic Field Analysis ◽  
The Cost ◽  
The Magnetic Field ◽  
Flux Leakage

Magnetic flux leakage is one type of electromagnetic nondestructive testing (NDT) which is widely utilized in the testing the integrity of drill pipe in the field. In this paper, the 3D model of excitation unit is completely built and analyzed by ANSYS software. The magnetic field of drill pipe in the combination of full excitation device is showed by ANSYS software instead of the physic experiments which increases the efficiency tremendously and decreases the cost and achieves the anticipated desire. It is considered that this technique can provide the theoretical basis of drill pipe excitation device and the magnetic flux leakage testing of drill pipe.

Magnetic Field Analysis of Surface-Mounted Permanent-Magnet Motors

2011 ◽  
Vol 52-54 ◽  
pp. 285-290
Author(s):  
Yi Chang Wu ◽  
Feng Ming Ou ◽  
Bo Wei Lin
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Magnetic Circuit ◽  
Circuit Model ◽  
Field Analysis ◽  
Permanent Magnet Motors ◽  
Element Analysis ◽  
Magnetic Field Analysis ◽  
Field Estimation ◽  
The Magnetic Field

The prediction of the magnetic field is a prerequisite to investigate the motor performance. This paper focuses on the magnetic field estimation of surface-mounted permanent-magnet (SMPM) motors based on two approximations, i.e., the magnetic circuit analysis and the finite-element analysis (FEA). An equivalent magnetic circuit model is applied to analytically evaluate the magnetic field of a SMPM motor with exterior-rotor configuration. The two-dimensional FEA is then applied to numerically calculate the magnetic field and to verify the validity of the magnetic circuit model. The results show that the errors between the analytical predictions and FEA results are less than 6%. It is of benefit to further design purposes and optimization of SMPM motors.

Magnetic Field Analysis for Magnetron Sputtering Apparatus for Accurate Composition Control

2009 ◽  
Vol 154 ◽  
pp. 175-179 ◽  
Author(s):  
Yutaka Sakurai ◽  
Ryo Nakajima ◽  
Hiroko Nakamura
Keyword(s):  
Magnetic Field ◽  
Finite Element Method ◽  
Magnetron Sputtering ◽  
Field Analysis ◽  
The Finite Element Method ◽  
Film Composition ◽  
Composite Target ◽  
Composition Control ◽  
Magnetic Field Analysis ◽  
The Magnetic Field

Authors use magnetron sputtering technique for controlling the film composition by modifying the magnetic field with an external solenoid in addition to the magnetic field with a permanent magnet on back of composite target. It is necessary to understand the contribution of the solenoid quantitatively for the effective application of this technique. The magnetic field changes by the solenoid current on the target were calculated by the finite element method (FEM), and compared with the film composition. As the solenoid current increases, magnetic tunnel region on the target (correspond with the well sputtered region by the confined plasma) moves to the centre of the target. The behaviour corresponds with the actually formed film composition. The calculated results also give an information to design the composite target and the correction value for using the already eroded target.

Magnetic Field Analysis of the Actuator in a Semi-Active Vibration Control of the Beam with MR Fluid

2015 ◽  
Vol 759 ◽  
pp. 37-44
Author(s):  
Mateusz Romaszko ◽  
Łukasz Łacny
Keyword(s):  
Magnetic Field ◽  
Vibration Control ◽  
Field Distribution ◽  
Active Vibration Control ◽  
Magnetic Field Distribution ◽  
Field Analysis ◽  
Mr Fluid ◽  
Active Vibration ◽  
Comparison Of The Results ◽  
The Magnetic Field

In this study the analysis of the magnetic field distribution of an electromagnet is presented. This electromagnet is used as an actuator in a semi-active vibration control of the three-layer beam with MR fluid. Two separate numerical methods are used for the purpose of calculating the magnetic field distribution. The first method is based on the Finite Element Method and implemented using ANSYS software. The second, simplified one is based on the assumption that the electromagnet can be substituted by a simple magnetic circuit divided into separate paths, with each sub-path defined by the value of reluctance of the corresponding electromagnet part. The comparison of the results from both methods with the ones obtained from an experiment is also presented and analyzed in the paper.

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