Automated Non-Destructive Evaluation of Spot Welds using the Imaging Analyses of the Residual Magnetic Flux Density

2019 ◽  
Author(s):  
Christian Mathiszik ◽  
◽  
Jörg Zschetzsche ◽  
Uwe Füssel
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Magnetic Flux Density ◽  
Spot Welds ◽  
Non Destructive Evaluation ◽  
Non Destructive

scholarly journals Концептуальная модель квазибессилового магнита малого объема c инерционным удержанием его торцевой части

2021 ◽  
Vol 47 (11) ◽  
pp. 40
Author(s):  
Г.А. Шнеерсон ◽  
А.А. Парфентьев ◽  
В.В. Титков ◽  
С.И. Кривошеев ◽  
А.Д. Лагуткина ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Mechanical Strength ◽  
Flux Density ◽  
Pulse Duration ◽  
Small Volume ◽  
Characteristic Dimension ◽  
Magnetic Flux Density ◽  
Superstrong Magnetic Field ◽  
Non Destructive

The efficiency of using a diamagnetic screen with inertial retention in a non-destructive quasi-force-free magnet of a small volume (with a characteristic dimension about 10 cm^3 ) for generating a superstrong magnetic field with a pulse duration of about 10 µs is shown. A configuration of the magnet was developed, in which the end part of the winding is balanced due to the fact that the screen virtually does not move during the discharge. Mechanical stresses in the winding were calculated, and it was demonstrated that mechanical strength of the winding can be ensured in a field with magnetic flux density up to 100T. Calculations of the heating of the winding were performed and the possibilities of its reduction to an acceptable level are indicated.

Three-Dimensional Scanning Hall Probe Microscopy for Final Stage of Crack Growth of Chromium Molybdenum Steel SCM440

2017 ◽  
Vol 748 ◽  
pp. 386-390
Author(s):  
Tatsurou Nakashima ◽  
Katsuyuki Kida
Keyword(s):  
Magnetic Flux ◽  
Crack Propagation ◽  
Crack Growth ◽  
Flux Density ◽  
Evaluation Method ◽  
Three Dimensional ◽  
Vertical Component ◽  
Magnetic Flux Density ◽  
Hall Probe ◽  
Non Destructive

Crack propagation around the stress concentration area causes fatigue failure. Non-destructive method is necessary for monitoring structure fatigue before destruction. We focused on a magnetic non-destructive evaluation method for crack growth. In order to understand the relation between crack propagation and changes in magnetic flux density, we observed the position of the positive and negative magnetic flux density distributions around the crack of tool steel (SCM440) plate using a scanning Hall probe microscope (SHPM). We found that the vertical component of the three-dimensional magnetic flux density moved as the crack growth. Furthermore, the magnetic component which is parallel to the tensile stress appeared just before destruction of the specimen.

scholarly journals Design of a New 1D Halbach Magnet Array with Good Sinusoidal Magnetic Field by Analyzing the Curved Surface

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2522
Author(s):  
Guangdou Liu ◽  
Shiqin Hou ◽  
Xingping Xu ◽  
Wensheng Xiao
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Permanent Magnet ◽  
Flux Density ◽  
Permanent Magnets ◽  
Air Gap ◽  
Curved Surface ◽  
Magnetic Flux Density ◽  
Sinusoidal Magnetic Field ◽  
The Magnetic Field

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.

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