scholarly journals Giant magneto resistance (GMR) sensors for non destructive testing

2021 ◽  
Author(s):  
◽  
Joseph Bailey
Keyword(s):  
Magnetic Field ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Current Frequency ◽  
Steel Pipes ◽  
Electronic Measurement ◽  
Gmr Sensors ◽  
Non Destructive ◽  
Magneto Resistance ◽  
The Magnetic Field

<p>The thesis investigates the use of giant magneto resistance sensors for eddy current testing in order to identify defects in steel pipes. An automated test rig which included the device under test, sensor array, excitation unit, electronic measurement equipment, mechanical setup and LabVIEW automation was designed and built. This was used to investigate the effect of excitation parameters such as current, frequency and distance to the pipe. Some preliminary algorithms to improve the signal were developed and tested. The effect of the shape and size of the defect and aluminum shield on the magnetic field was investigated. A qualitative model to describe the magnetic field, including measured defect signals, was developed. Minimum defect parameters and maximum distance values were evaluated in the context of signal to noise.</p>

scholarly journals Giant magneto resistance (GMR) sensors for non destructive testing

2021 ◽  
Author(s):  
◽  
Joseph Bailey
Keyword(s):  
Magnetic Field ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Current Frequency ◽  
Steel Pipes ◽  
Electronic Measurement ◽  
Gmr Sensors ◽  
Non Destructive ◽  
Magneto Resistance ◽  
The Magnetic Field

<p>The thesis investigates the use of giant magneto resistance sensors for eddy current testing in order to identify defects in steel pipes. An automated test rig which included the device under test, sensor array, excitation unit, electronic measurement equipment, mechanical setup and LabVIEW automation was designed and built. This was used to investigate the effect of excitation parameters such as current, frequency and distance to the pipe. Some preliminary algorithms to improve the signal were developed and tested. The effect of the shape and size of the defect and aluminum shield on the magnetic field was investigated. A qualitative model to describe the magnetic field, including measured defect signals, was developed. Minimum defect parameters and maximum distance values were evaluated in the context of signal to noise.</p>

Characterization of Magnetic Field in Crack Propagation Stage and Application to Non-Destructive Evaluation

2020 ◽  
Author(s):  
Sheng Bao ◽  
Zhengye Zhao ◽  
Qiang Luo ◽  
Jian Yang
Keyword(s):  
Magnetic Field ◽  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Crack Propagation ◽  
Magnetic Measurement ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Non Destructive ◽  
The Magnetic Field

Abstract Monitoring of fatigue crack propagation is very important in industrial fields. Stress-induced magnetic measurement is a newly developed non-destructive testing technique which can detect early failure of ferromagnetic materials in service. A lot of experiments demonstrate that magnetic measurement is more sensitive compared with other non-destructive testing technologies. In order to explore the correlation between crack propagation and magnetic hysteresis under cyclic stress in X70 pipeline steel, a series of stress-controlled tests were carried out and the changes in magnetic field around cracks during their propagation process were observed throughout the tension-tension fatigue tests. The variations of magnetic field and stress intensity factor K in the crack propagation stage were studied. The results obtained allowed the division of the magnetic behavior of the investigated steels into three stages corresponding to three distinct crack propagation stages. It was found that the magnetic field varies with crack propagation, and the stress intensity factor K increased with the increase of loading cycles. A strong correlation between the variation of the magnetic field and stress intensity factor was recognized, regardless of the loading conditions, maximum load or stress ratio. The results suggest that non-destructive evaluation of fatigue cracks would be possible using this relationship.

INSPECTION BY ULTRASONIC TOMOGRAPHY (UT) LEADING TREND IN WELDING JOINT MONITORING

2015 ◽  
Vol 77 (17) ◽  
Author(s):  
Noor Amizan Abd. Rahman ◽  
Ruzairi Abdul Rahim ◽  
Nor Muzakkir Nor Ayob ◽  
Jaysuman Pusppanathan ◽  
Fazlul Rahman Mohd Yunus ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Image Resolution ◽  
Ultrasonic Tomography ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Steel Pipes ◽  
Imaging Result ◽  
Welding Steel ◽  
Joint Monitoring ◽  
Non Destructive

Welding work is a connection process between the structure and the materials. This process is used in the construction, maintenance and repair especially mechanical engineering. This study discusses the type of welding used in the industry, mainly involving the pipeline welds. On-demand need to every work process when finishing weld requires quality tests to ensure compliance to the standards required. Monitoring through the display image has long been used in Non-Destructive Testing (NDT). Various methods of monitoring used in NDT focused on Ultrasonic Tomography (UT) as a method used in NDT and as an option for the future. Previous imaging result was in two-dimensional (2D) and then upgraded to a three-dimensional image (3D). Besides, there is potential of 3D imaging beyond the existing limits in terms of size, material thickness, especially for welding steel pipes. Achievement through research of existing pipe size so far outside diameter of 200 mm and a thickness of 5.8 mm should be limited in view of the obstacles to enhanced image resolution is less effective when compared to other tomography methods.

Electromagnetic Effect of Eddy Currents in Composites with Conductive Components: Magnetic Field Strengthening and its Simple Analytical Estimation

2018 ◽  
Vol 284 ◽  
pp. 37-42 ◽  
Author(s):  
R.R. Sattarov ◽  
T.A. Volkova ◽  
I.Z. Gubaydullin
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Compatibility ◽  
Eddy Currents ◽  
Electromagnetic Effect ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Compatibility Analysis ◽  
Dynamic Materials ◽  
Analytical Estimation ◽  
Non Destructive

Composites and dynamic materials that include conductive components are becoming a suitable choice in different applications. The eddy currents are generated when the conductive components are placed in alternating magnetic field. The eddy currents decrease the primary field and this effect has been well studied and it is used for electromagnetic shielding. Besides, the magnetic field increases in small space near edges of the conductive components. While this effect of magnetic field strengthening is known, it is rarely examined. We will introduce a simple model that can be appropriate for the conductive components in form of long thin sheets. We analytically analyze the model and obtain expressions that give upper bounds for increasing of the net magnetic field. The electromagnetic effect of strengthening should be taken into account when considering an application of the composites. The results are useful for electromagnetic compatibility analysis, non-destructive testing and monitoring of composite and dynamic materials with conductive components.

A Non-Destructive Testing Based on Electromagnetic Measurements and Neural Networks for the Inspection of Concrete Structures

2011 ◽  
Vol 301-303 ◽  
pp. 597-602 ◽  
Author(s):  
Naasson P. de Alcantara ◽  
Danilo C. Costa ◽  
Diego S. Guedes ◽  
Ricardo V. Sartori ◽  
Paulo S. S. Bastos
Keyword(s):  
Neural Networks ◽  
Concrete Structures ◽  
Concrete Surface ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Electromagnetic Devices ◽  
Electromagnetic Measurements ◽  
Steel Bars ◽  
Non Destructive ◽  
The Magnetic Field

This paper presents a new non-destructive testing (NDT) for reinforced concrete structures, in order to identify the components of their reinforcement. A time varying electromagnetic field is generated close to the structure by electromagnetic devices specially designed for this purpose. The presence of ferromagnetic materials (the steel bars of the reinforcement) immersed in the concrete disturbs the magnetic field at the surface of the structure. These field alterations are detected by sensors coils placed on the concrete surface. Variations in position and cross section (the size) of steel bars immersed in concrete originate slightly different values for the induced voltages at the coils.. The values ​​for the induced voltages were obtained in laboratory tests, and multi-layer perceptron artificial neural networks with Levemberg-Marquardt training algorithm were used to identify the location and size of the bar. Preliminary results can be considered very good.

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