Optimal Design to Ensure Maximum Coupling Between Magnetic Flux and Arterial Blood in a Magneto Plethysmo Gram Sensor Head

In this study, an automated cable monitoring system using a NDE technique and a cable climbing robot is proposed. MFL (Magnetic Flux Leakage- based inspection system was applied to monitor the condition of cables. This inspection system measures magnetic flux to detect the local faults (LF) of steel cable. To verify the feasibility of the proposed damage detection technique, an 8-channel MFL sensor head prototype was designed and fabricated. A steel cable bunch specimen with several types of damage was fabricated and scanned by the MFL sensor head to measure the magnetic flux density of the specimen. To interpret the condition of the steel cable, magnetic flux signals were used to determine the locations of the flaws and the level of damage. Measured signals from the damaged specimen were compared with thresholds set for objective decision making. In addition, the measured magnetic flux signal was visualized into a 3D MFL map for convenient cable monitoring. Finally, the results were compared with information on actual inflicted damages to confirm the accuracy and effectiveness of the proposed cable monitoring method.

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Cross-Sectional Damage Localization and Quantification for Steel Cables Using MFL 3D Imaging Technique

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.281.55 ◽

2013 ◽

Vol 281 ◽

pp. 55-58

Author(s):

Dong Hwan Lee ◽

Ju Won Kim ◽

Chang Gil Lee ◽

Seung Hee Park ◽

Jong Jae Lee

Keyword(s):

Magnetic Flux ◽

Permanent Magnets ◽

Digital Signal ◽

Magnetic Flux Density ◽

Inspection System ◽

Steel Cable ◽

Cross Sectional ◽

Sensor Head ◽

Damage Level ◽

Steel Cables

In this study, a MFL (Magnetic Flux Leakage) based 3D inspection system which is incorporated into a cable climbing robot was investigated to monitor the healthy condition of steel cables. Firstly, a MFL sensor head prototype composed of two permanent magnets and eight hall sensors was designed and fabricated. A steel cable specimen with several types of damage, such as corrosion and cutting, was inflicted and scanned by the MFL sensor head to measure the magnetic flux density of the specimen. The measured MFL signals were used to interpret the healthy condition of the steel cable. For improving the resolution and quantification of the damage level, digital signal processing techniques were performed. In addition, the measured MFL signals were visualized into a 3D MFL map for real-time and online cable monitoring. This visualized MFL map can provide the information about location, shape and size of damages very intuitively. Finally, the results were compared with information on actual inflicted damages to confirm the accuracy and effectiveness of the MFL based cable inspection system.

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Optimal Design of Magnetic Flux Concentrators in Induction Heating

2019 XXI International Conference Complex Systems: Control and Modeling Problems (CSCMP) ◽

10.1109/cscmp45713.2019.8976484 ◽

2019 ◽

Author(s):

Marco Baldan ◽

Mustafa Cetin ◽

Alexander Nikanorov ◽

Bernard Nacke

Keyword(s):

Optimal Design ◽

Magnetic Flux ◽

Induction Heating

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Magnetic Flux Leakage Sensing-Based Steel Cable NDE Technique

Shock and Vibration ◽

10.1155/2014/929341 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 18

Author(s):

Seunghee Park ◽

Ju-Won Kim ◽

Changgil Lee ◽

Jong-Jae Lee

Keyword(s):

Magnetic Flux ◽

Magnetic Flux Leakage ◽

Magnetic Flux Density ◽

Inspection System ◽

Steel Cable ◽

Monitoring Method ◽

Sensor Head ◽

Long Span Bridges ◽

Long Span ◽

Flux Leakage

Nondestructive evaluation (NDE) of steel cables in long span bridges is necessary to prevent structural failure. Thus, an automated cable monitoring system is proposed that uses a suitable NDE technique and a cable-climbing robot. A magnetic flux leakage- (MFL-) based inspection system was applied to monitor the condition of cables. This inspection system measures magnetic flux to detect the local faults (LF) of steel cable. To verify the feasibility of the proposed damage detection technique, an 8-channel MFL sensor head prototype was designed and fabricated. A steel cable bunch specimen with several types of damage was fabricated and scanned by the MFL sensor head to measure the magnetic flux density of the specimen. To interpret the condition of the steel cable, magnetic flux signals were used to determine the locations of the flaws and the levels of damage. Measured signals from the damaged specimen were compared with thresholds that were set for objective decision-making. In addition, the measured magnetic flux signals were visualized as a 3D MFL map for intuitive cable monitoring. Finally, the results were compared with information on actual inflicted damages, to confirm the accuracy and effectiveness of the proposed cable monitoring method.

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Magnetic flux leakage–based local damage detection and quantification for steel wire rope non-destructive evaluation

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x17721038 ◽

2017 ◽

Vol 29 (17) ◽

pp. 3396-3410 ◽

Cited By ~ 9

Author(s):

Ju-Won Kim ◽

Seunghee Park

Keyword(s):

Magnetic Flux ◽

Damage Detection ◽

Permanent Magnets ◽

Steel Wire ◽

Threshold Value ◽

Wire Rope ◽

Magnetic Flux Leakage ◽

Magnetic Flux Density ◽

Sensor Head ◽

Flux Leakage

A magnetic flux leakage method was applied to detect damage when inspecting steel wire rope. A multi-channel magnetic flux leakage sensor head was fabricated using Hall sensors and permanent magnets to adapt to the wire rope. Three types of artificial damage were created on a wire rope specimen. The magnetic flux leakage sensor head scanned the damaged specimen to measure the magnetic flux density while the damage was expanding in three steps. Signal processing processes including the enveloping process based on Hilbert transform were performed to clarify the flux leakage signal due to the damage. The enveloped signals were then analyzed for objective damage detection by comparing with the threshold value. For improvement of quantitative analysis, three types of new damage indexes that utilize the relationship between the enveloped magnetic flux leakage signal and the threshold value were additionally proposed. By using the proposed damage indexes and the general damage indexes for the magnetic flux leakage method, the detected magnetic flux leakage signals from each damage type were quantified. The trends of the extracted damage indexes according to damage levels were analyzed to examine the applicability and reliability of the proposed damage indexes for the magnetic flux leakage based wire rope inspection.

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Optimal design of a novel hybrid MR brake for motorcycles considering axial and radial magnetic flux

Smart Materials and Structures ◽

10.1088/0964-1726/21/5/055003 ◽

2012 ◽

Vol 21 (5) ◽

pp. 055003 ◽

Cited By ~ 41

Author(s):

Q H Nguyen ◽

S B Choi

Keyword(s):

Optimal Design ◽

Magnetic Flux

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Optimal design of a three phase magnetic flux leakage transformer for industrial microwave generators

Bulletin of Electrical Engineering and Informatics ◽

10.11591/eei.v9i1.1679 ◽

2020 ◽

Vol 9 (1) ◽

pp. 57-66

Author(s):

Hamid Outzguinrimt ◽

Mohammed Chraygane ◽

Mouhcine Lahame ◽

Rajaa Oumghar ◽

Ali Bouzit ◽

...

Keyword(s):

Optimal Design ◽

Magnetic Flux ◽

Active Material ◽

Optimal Solution ◽

Computation Time ◽

Search Space ◽

Global Optimum ◽

Magnetic Flux Leakage ◽

Three Phase ◽

Flux Leakage

This paper aims to get an optimal high voltage magnetic flux leakage transformer design of a three-phase shell type. Optimal design of transformer requires determination of design variables to optimize a particular objective and satisfying a set of constraints. The objective function is to minimize the total mass and reduce the volume of the transformer. This function depends on inputs, which are divided into optimization variables. Each optimization variable varies within a certain interval thus defining a global search space. It is within this space that we seek the optimal solution. The constraints: maximum and average current of magnetron anode are part of the problem in order to limit the overall search space. The results obtained indicate that the method has provided a global optimum. The computation time and cost of active material are much reduced compared with the conventional design results.

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Emergence of Twisted Magnetic Flux Related Sigmoidal Brightening

International Astronomical Union Colloquium ◽

10.1017/s0252921100064630 ◽

2000 ◽

Vol 179 ◽

pp. 263-264

Author(s):

K. Sundara Raman ◽

K. B. Ramesh ◽

R. Selvendran ◽

P. S. M. Aleem ◽

K. M. Hiremath

Keyword(s):

Magnetic Field ◽

Magnetic Fields ◽

Magnetic Flux ◽

Ultra Violet ◽

Active Regions ◽

Morphological Properties ◽

Energy Storage And Conversion ◽

The Sun ◽

X Rays ◽

The Magnetic Field

Extended AbstractWe have examined the morphological properties of a sigmoid associated with an SXR (soft X-ray) flare. The sigmoid is cospatial with the EUV (extreme ultra violet) images and in the optical part lies along an S-shaped Hαfilament. The photoheliogram shows flux emergence within an existingδtype sunspot which has caused the rotation of the umbrae giving rise to the sigmoidal brightening.It is now widely accepted that flares derive their energy from the magnetic fields of the active regions and coronal levels are considered to be the flare sites. But still a satisfactory understanding of the flare processes has not been achieved because of the difficulties encountered to predict and estimate the probability of flare eruptions. The convection flows and vortices below the photosphere transport and concentrate magnetic field, which subsequently appear as active regions in the photosphere (Rust & Kumar 1994 and the references therein). Successive emergence of magnetic flux, twist the field, creating flare productive magnetic shear and has been studied by many authors (Sundara Ramanet al.1998 and the references therein). Hence, it is considered that the flare is powered by the energy stored in the twisted magnetic flux tubes (Kurokawa 1996 and the references therein). Rust & Kumar (1996) named the S-shaped bright coronal loops that appear in soft X-rays as ‘Sigmoids’ and concluded that this S-shaped distortion is due to the twist developed in the magnetic field lines. These transient sigmoidal features tell a great deal about unstable coronal magnetic fields, as these regions are more likely to be eruptive (Canfieldet al.1999). As the magnetic fields of the active regions are deep rooted in the Sun, the twist developed in the subphotospheric flux tube penetrates the photosphere and extends in to the corona. Thus, it is essentially favourable for the subphotospheric twist to unwind the twist and transmit it through the photosphere to the corona. Therefore, it becomes essential to make complete observational descriptions of a flare from the magnetic field changes that are taking place in different atmospheric levels of the Sun, to pin down the energy storage and conversion process that trigger the flare phenomena.

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