scholarly journals Magnetic field of a radial tire after puncture caused by ferromagnetic elements

2018 ◽  
Vol 3 (21) ◽  
pp. 183-194
Author(s):  
Agnieszka Szegda ◽  
Stanisław Radkowski ◽  
Sebastian Brol

Tire, an element of wheel, is made in a sophisticated vulcanization process of many components and some of which such as: bead wire, belt and carcass exhibit ferromagnetic properties. Such components create variable in direction and intensity magnetic field, which expands around tire and the complete wheel. Since the layout of magnetic field is exceptional for every single wheel many of information might be obtained on the basis of it alteration. The reported since now application concentrates on rotational speed measurement, wheel rotations counting and therefore also vehicle linear speed and distance estimation. However up to the present the known solutions did not describe changes in magnetic field in case of damage induced by e.g. puncture caused by ferromagnetic elements. This paper’s aim is to test the thesis that it is possible to detect puncture in tire made by ferromagnetic element by using measurement and analysis of changes of magnetic flux density around tire. The tests were executed using original measuring device, designed especially for such experiments. It registers a magnetic profile, which consists of data series of magnetic flux density measured in this investigations 55 mm above tire’s tread and arranged along with rotation angle. Tire magnetic properties were assessed by using of circumferential magnetic profiles and parameters such as: minimum value (Mmin), maximum value (Mmax), peak to peak value (Mm), average value of ordinates of profile (Mb), skewness of ordinate distribution (Ms) and kurtosis of ordinate distribution (Mk). Magnetic profiles before after puncture were analysed as well as the parameters. Moreover differential signal caused by puncture were determined. It turned out that detected changes are directly related to tire damage and showing in rotation angle where puncture occurs.

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2522
Author(s):  
Guangdou Liu ◽  
Shiqin Hou ◽  
Xingping Xu ◽  
Wensheng Xiao

In the linear and planar motors, the 1D Halbach magnet array is extensively used. The sinusoidal property of the magnetic field deteriorates by analyzing the magnetic field at a small air gap. Therefore, a new 1D Halbach magnet array is proposed, in which the permanent magnet with a curved surface is applied. Based on the superposition of principle and Fourier series, the magnetic flux density distribution is derived. The optimized curved surface is obtained and fitted by a polynomial. The sinusoidal magnetic field is verified by comparing it with the magnetic flux density of the finite element model. Through the analysis of different dimensions of the permanent magnet array, the optimization result has good applicability. The force ripple can be significantly reduced by the new magnet array. The effect on the mass and air gap is investigated compared with a conventional magnet array with rectangular permanent magnets. In conclusion, the new magnet array design has the scalability to be extended to various sizes of motor and is especially suitable for small air gap applications.


2010 ◽  
Vol 129-131 ◽  
pp. 692-696
Author(s):  
Jian Bing Meng ◽  
Xiao Juan Dong ◽  
Chang Ning Ma

A mathematical model was developed to describe the oscillating amplitude of the plasma arc injected transverse to an external transverse alternating magnetic field. The characteristic of plasma arc under the external transverse alternating magnetic field imposed perpendicular to the plasma current was discussed. The effect of processing parameters, such as flow rate of working gas, arc current, magnetic flux density and the standoff from the nozzle to the workpiece, on the oscillation of plasma arc were also analyzed. The results show that it is feasible to adjust the shape of the plasma arc by the transverse alternating magnetic field, which expands the region of plasma arc thermal treatment upon the workpiece. Furthermore, the oscillating amplitude of plasma arc decreases with decrease of the magnetic flux density. Under the same magnetic flux density, more gas flow rate, more arc current, and less standoff cause the oscillating amplitude to decrease. The researches have provided a deeper understanding of adjusting of plasma arc characteristics.


Open Physics ◽  
2017 ◽  
Vol 15 (1) ◽  
pp. 997-1003
Author(s):  
Antonio Poveda-Lerma ◽  
Guillermo Serrano-Callergues ◽  
Martin Riera-Guasp ◽  
Manuel Pineda-Sanchez ◽  
Ruben Puche-Panadero ◽  
...  

AbstractIn this paper the lamination effect on the model of a power transformer’s core with stacked E-I structure is analyzed. The distribution of the magnetic flux in the laminations depends on the stacking method. In this work it is shown, using a 3D FEM model and an experimental prototype, that the non-uniform distribution of the flux in a laminated E-I core with alternate-lap joint stack increases substantially the average value of the magnetic flux density in the core, compared with a butt joint stack. Both the simulated model and the experimental tests show that the presence of constructive air-gaps in the E-I junctions gives rise to a zig-zag flux in the depth direction. This inter-lamination flux reduces the magnetic flux density in the I-pieces and increases substantially the magnetic flux density in the E-pieces, with highly saturated points that traditional 2D analysis cannot reproduce. The relation between the number of laminations included in the model, and the computational resourses needed to build it, is also evaluated in this work.


2019 ◽  
Vol 9 (3) ◽  
pp. 22
Author(s):  
António Roque ◽  
Duarte M. Sousa ◽  
Pedro Sebastião ◽  
Elmano Margato ◽  
Gil Marques

This paper describes an innovative solution for the power supply of a fast field cycling (FFC) nuclear magnetic resonance (NMR) spectrometer considering its low power consumption, portability and low cost. In FFC cores, the magnetic flux density must be controlled in order to perform magnetic flux density cycles with short transients, while maintaining the magnetic flux density levels with high accuracy and homogeneity. Typical solutions in the FFC NMR literature use current control to get the required magnetic flux density cycles, which correspond to an indirect magnetic flux density control. The main feature of this new relaxometer is the direct control of the magnetic flux density instead of the magnet current, in contrast with other equipment available in the market. This feature is a great progress because it improves the performance. With this solution it is possible to compensate magnetic field disturbances and parasitic magnetic fields guaranteeing, among other possibilities, a field control below the earth magnetic field. Experimental results validating the developed solution and illustrating the real operation of this type of equipment are shown.


Author(s):  
Seok Woo Lee ◽  
Seung S. Lee

In this paper, PDMS membrane for a large displacement is fabricated by new fabrication process which can be integrated with electrical components on substrates fabricated by conventional microfabrication processes and the performance of the membrane using electromagnetism was evaluated. Rectangular PDMS membranes are designed as 2mm and 3mm in width, respectively and are actuated by Lorentz force induced by current paths spread on the membrane. The PDMS membrane is fabricated by reducing a viscosity of uncured PDMS with dilution and spin coating on the substrate on which electric components generating Lorentz force. Finally, PDMS membrane including electric components is opened by a bulk micromachining. The device is tested in magnetic field induced by Nd-Fe-B magnet whose magnetic flux density is 90G. When applied currents are 20, 25, and 30mA, the maximum deflections of membranes are 1.21, 3.07, and 20.2μm for 1.5mm width membrane and 3.34, 31.0, and 50.9μm for width 3mm membrane, respectively. The large displacement PDMS membrane actuator has potentially various applications such as fluidics, optics, acoustics, and electronics. Currently, we are planning to measure the optical performance of the actuator as a focal tunable liquid lens.


Author(s):  
Ping-Hsun Lee ◽  
Jen-Yuan (James) Chang

Abstract In this paper we proposed a platform for measuring shear force of magnetorheological (MR) fluid by which the relationship of yield stress and magnetic flux density of specific material can be determined. The device consisted of a rotatable center tube in a frame body and the magnetic field was provided by two blocks of permanent magnets placed oppositely outside the frame body. The magnitude and direction of the magnetic field were manipulated by changing the distance of the two permanent magnets from the frame body and rotating the center tube, respectively. For determining the magnetic field of the device, we adopted an effective method by fitting the FEM (finite element method) result to the measured one and then rebuilt the absent components to approximate the magnetic field, which was hardly to be measured simultaneously as different device setup were required. With the proposed platform and analytical methods, the drawing shear force and the corresponding yield stress contributed by MR fluid could be evaluated in respect to the magnitude and direction of given magnetic flux density with acceptable accuracy for specific designing purposes without a large, complex, and expensive instrument.


1999 ◽  
Vol 3 (2) ◽  
pp. 157-161 ◽  
Author(s):  
Yunbo Zhong ◽  
Zhongming Ren ◽  
Kang Deng ◽  
Guochang Jiang ◽  
Kuangdi Xu

2014 ◽  
Vol 565 ◽  
pp. 133-137
Author(s):  
Athirot Mano ◽  
Wisut Titiroongruang

In a measurement of magnetic flux density with high accuracy by using Hall effect sensor must be considered position of Hall sensor, that perfect perpendicular with magnetic flux line for measurement. Only one Hall element can cause measuring error. Therefore, this paper presents an application of independent directional magnetic field measurement technique on two dimensions for high accuracy magnetometer. It is presented by using two Hall sensors locate perpendicular to each other and use the relation of the two voltage output signal from both Hall sensors to calculate constant Hall voltage and Magnetic flux density with high accuracy by using trigonometric function with Lab-View programming. And as the result of experiment, this technique can reduce the limitation in term of this angle in the range magnetic flux density can be measured 0-1800 gauss. A calibration curve of this system compare with standard Gauss meter shows the coefficient of determination (R2) equal to 1 and has the accuracy percentage as less than 0.5%.


Author(s):  
Gui-Ping Zhu ◽  
Nam-Trung Nguyen

This paper reports the numerical and experimental investigation on magnetic particle concentration in a uniform magnetic field. The flow system consists of water-based ferrofluid and glycerol/DI water mixture streams. Two regimes were observed with spreading and mixing phenomena. With a low magnetic field strength, the spread of magnetic particles is caused by improved diffusion migration. With a relatively high field strength, instability at the interface would occur due to the mismatch in magnetization of the fluid streams. The transport of magnetic particles is induced by chaotic mixing of the fluids caused by a secondary flow. The mixing phenomena are characterized by magnetic flux density. For configuration with flow rate and viscosity ratio (between diamagnetic and magnetic streams) being set at 1 and 0.5, the mixing efficiency analyzed based on magnetic particles concentration increases approximately by 0.3 at around 3.5 mT. This value of magnetic flux density indicates the requirement on instability inception. The mixing efficiency increases with magnetic flux density increases further. Complete mixing can be achieved with a magnetic flux density at around 10 mT. The magnetic approach offers a wireless, heat-free and pH-independent solution for a lab-on-a-chip system.


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