scholarly journals Examining Ferromagnetic Materials Subjected to a Static Stress Load Using the Magnetic Method

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3455
Author(s):  
Tomasz Chady ◽  
Ryszard Łukaszuk
Keyword(s):  
Statistical Analysis ◽  
Measurement System ◽  
Rolling Direction ◽  
Hysteresis Loops ◽  
Ferromagnetic Materials ◽  
Static Stress ◽  
Magnetic Method ◽  
Experimental Examination ◽  
Stress Load ◽  
Anisotropic Steel

This paper discusses the experimental examination of anisotropic steel-made samples subjected to a static stress load. A nondestructive testing (NDT) measurement system with a transducer, which enables observation of local hysteresis loops and detection of samples’ inhomogeneity, is proposed. Local hysteresis loops are measured on two perpendicular axes, including one parallel to the rolling direction of the samples. The results confirm that the selected features of the local hysteresis loops provide important information about the conditions of ferromagnetic materials. Furthermore, it is shown that the selected parameters of the statistical analysis of the achieved measurements are beneficial for evaluating stress and fatigue changes induced in the material.

STUDY OF THE TEXTURING IN BSCCO-AG TAPES THROUGH MAGNETIC MEASUREMENTS

2000 ◽  
Vol 14 (25n27) ◽  
pp. 3159-3164
Author(s):  
C. FERDEGHINI ◽  
M. R. CIMBERLE ◽  
G. GRASSO ◽  
P. GUASCONI ◽  
A. MALAGOLI ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Magnetic Measurements ◽  
Texture Evolution ◽  
Rolling Direction ◽  
Longitudinal Direction ◽  
Magnetic Method ◽  
Superconducting Compounds

We have developed a method that allows, by a simple set of magnetic measurements, to study the texturing of the grains inside a BSCCO-Ag tape. Because the texture is anisotropic we define the angle ϑ L that identifies the mean grain misalignment angle with respect to the tape surface in longitudinal direction (i.e. rolling direction) and the angle ϑ T in transverse direction. The technique is based on the assumption that, because of the very high anisotropy of the critical current density in BSCCO superconducting compounds, the magnetic moment is essentially generated by the current circulating in the a-b planes of the BSCCO grains. The different magnetisation cycles, measured when the orientation of the magnetic field with respect to the tape surface is changed, depend only on the grain orientation inside the tape, which determines the effective magnetic field component normal to the a-b planes of the grains. Here we present the texture evolution of the BSCCO grains inside silver sheated multifilamentary tape starting from the initial steps of the mechanical deformation up to the final heating stage. The results obtained from the magnetic method are compared with those obtained with other methods, i.e. X-ray diffraction and critical current density anisotropy. Also results obtained on samples prepared in different way will be presented.

scholarly journals Application of Magnetic Noise Method to Control the Mechanical Anisotropy of Ferromagnetic Materials

2019 ◽  
Vol 10 (3) ◽  
pp. 281-292
Author(s):  
V. N. Busko ◽  
A. A. Osipov
Keyword(s):  
Mechanical Properties ◽  
Magnetic Anisotropy ◽  
Sheet Metal ◽  
Elastic Deformation ◽  
Electrical Steel ◽  
Sheet Steel ◽  
Ferromagnetic Materials ◽  
Mechanical Anisotropy ◽  
Magnetic Method ◽  
Magnetic Noise

Presence of anisotropy of the ferromagnetic materials' properties determines the need for its research and control, since it has a significant impact on the basic physicomechanical characteristics of details, products and constructions. The aim of the work was to experimentally investigate the possibility of using the magnetic noise method for non-destructive testing of mechanical properties of ferromagnetic materials particularly value of the coefficient of normal anisotropy Rn of sheet metal, mechanical stresses under elastic deformation of electrical steel and the anisotropy of the physical and mechanical properties of ferromagnetic materials.Since the mechanical anisotropy is related to the magnetic anisotropy, the magnetic method of the Barkhausen effect (MBE) was used in its study, the informative parameters of which belong to the group of magnetic anisotropy. Comparison of the results of anisotropy evaluation on a set of samples of stamped sheet steel using the MBE with values Rn measured by the manufacturer showed their close match. This revealed the possibility of Rn level evaluation using the MBE. Device for circular rotation of the Barkhausen transducer on the sample surface and device for forming of elastic bending stresses in the sample were constructed. To study the magnetic anisotropy in various materials and the impact of elastic tensile and compressive stresses by bending on it using the MBE.It has been found that the elastic deformation in samples of electrical steel leads to dramatic change of the magnetic noise level and the shape of the circular diagrams, taking into account the sign of the stresses generated in the sample. It was established that as a result of cold rolling in the production process, electrical steel samples have a pronounced texture due to the direction of rolled sheet. The created elastic stresses in the considered range practically do not change the texture (induced crystallographic anisotropy) after the material rolling.The results can be useful for studying, monitoring and testing of anisotropy, crystallographic texture, structural heterogeneity of ferromagnetic materials in the form of sheet metal, sheet steel and coil steel, sheet metal forming and for solving other problems using the magnetic noise method in aboratory and workshop conditions.

The Generalized Dynamic Factor of Hydraulic Excavator Working Device

2015 ◽  
Vol 757 ◽  
pp. 75-80
Author(s):  
Zhi Gui Ren ◽  
Jin Chen ◽  
Xiao Ping Pang ◽  
Dong Sheng Zhang
Keyword(s):  
Statistical Analysis ◽  
Dynamic Stress ◽  
Static Strength ◽  
Static Stress ◽  
Strength Analysis ◽  
Dynamic Factor ◽  
Hydraulic Excavator ◽  
Test Points ◽  
Working Device

Synchronous test platforms were built to test the dynamic stress and working device attitude. The dynamic stress spectrums of all the test points under a variety of common conditions were obtained. The digging gestures corresponding to the peak of the dynamic stress spectrums were found out and taken as the specified digging gestures for the calculation of the static stress. The static stress nephogram of working device under the specified digging gestures was calculated using traditional static strength analysis. By conducting statistical analysis on the ratio of dynamic stress and static stress of all the testing points. Then, the range of generalized dynamic factor of working device was obtained.

Laboratory Comparison of Retroreflection Measurement System

2011 ◽  
Vol 308-310 ◽  
pp. 1041-1045 ◽  
Author(s):  
Wei Li ◽  
Chuan Zheng Zhu ◽  
Yong Yang
Keyword(s):  
Statistical Analysis ◽  
Test Data ◽  
Measurement System ◽  
Manufacturing Technology ◽  
Test Method ◽  
Measurement Systems ◽  
Safety Warning ◽  
National Test ◽  
Warning Effect

As the wide application of retroreflective materials, following problems such as safety warning effect, quality, manufacturing technology, test method become more and more important. Many national test centers or big manufactures build retroreflection measurement systems. In order to identify these laboratories’ ability, we organize this laboratory comparison. After 6 months experiments, this comparison successfully finishes. And all the test data are dealt with statistical analysis.

scholarly journals Might Cardiac Catheterization Influence Diurnal Rhythm of the Steroid Stress Hormones Secretion?

2012 ◽  
pp. 25-34 ◽  
Author(s):  
H. SKARLANDTOVÁ ◽  
M. BIČÍKOVÁ ◽  
P. NEUŽIL ◽  
M. MLČEK ◽  
V. HRACHOVINA ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Plasma Concentration ◽  
Stress Hormones ◽  
Circadian Variation ◽  
Young Female ◽  
Heart Catheterization ◽  
Limiting Factor ◽  
Early Age ◽  
Stress Load ◽  
Experimental Pigs

Glucocorticoids (GCs) are steroid hormones produced by the adrenal cortex in reaction to stress stimuli. GCs production is not stable over a 24-hour period; the plasma concentration peaks in the morning (approximately upon awakening) and then the plasma levels decrease, reaching the nadir in the evening. In our experiments, the levels of cortisol, cortisone, DHEA and DHEAS were tested in young female pigs (n=23) during heart catheterization at two different day times (in the morning and in the afternoon). The non-parametric Mann-Whitney test for statistical analysis was used. We found only minimal statistical differences in studied markers between the morning and afternoon group (p>0.05). The absence of circadian variation in GCs levels could originate either at an early age of our experimental pigs, or in stressful conditions on the experiment day, or most likely the day before (e.g. social isolation, fasting, transport, and catheterization), respectively. We can conclude there is no difference in the stress load between morning and afternoon experiments, and therefore we can assume the stress load is not a limiting factor for the timing when catheterization should be preferably performed.

Experimental Study on Electro-Magneto-Mechanical Behaviour of Electromagnetic Solids

2006 ◽  
Vol 326-328 ◽  
pp. 5-12
Author(s):  
Dai Ning Fang ◽  
Xu Jun Zhao ◽  
Yong Mao Pei ◽  
Zhan Wei Liu ◽  
Fa Xin Li ◽  
...  
Keyword(s):  
Electromagnetic Coupling ◽  
Hysteresis Loops ◽  
Correlation Method ◽  
Strain Curve ◽  
Ferromagnetic Materials ◽  
Ferroelectric Ceramics ◽  
Uniform Electric Field ◽  
Technical Problems ◽  
Digital Speckle Correlation Method ◽  
Electromagnetic Solids

New experiment systems that can offer electromechanical and electromagnetic coupling loads were established. Measurement skills and technologies under coupling loads have been developed. The experimental difficulties and technical problems, such as insulation, discharge, compressive testing of brittle ferroelectrics and so on, were well resolved. The constitutive experiments of piezo/ferroelectrics or ferromagnetic materials were carried out. Moiré Interferometry was applied to the measurement of transformation of the crack tip in ferroelectric ceramics under coupling loads. The deformation concentration near the internal electrode tip caused by non-uniform electric field was investigated by means of Digital Speckle Correlation Method (DSCM). With an aim to accomplish both measurements of constitutive response of the magnetostrictive materials and the fracture experiments of general soft ferromagnetic materials, a magnetomechanical-coupling testing setup was established, which is controlled by an industrial PC. The software was programmed to monitor the testing process and to deal with the acquired data. The characteristic curves of ferromagnetic materials, such as TbxDy1-xFe2 alloys, were measured, including the hysteresis loops, the magnetostriction curve and stress-strain curve.

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