The effect of higher harmonic components on MPI process

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21230%2F18%3A00322953" target="_blank" >RIV/68407700:21230/18:00322953 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.cinde.ca/conference/presentations/index.php?show=all" target="_blank" >https://www.cinde.ca/conference/presentations/index.php?show=all</a>

DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

The effect of higher harmonic components on MPI process

Popis výsledku v původním jazyce

Magnetic Particle Inspection (MPI) relies on magnetic forces driving small ferromagnetic particles. Such forces are caused by inhomogeneities (cracks) in ferromagnetic bodies perpendicular to magnetic field intensity. In order to detect defects in all possible directions it is essential to create rotating magnetic field tangential to the surface of the material under test. Such a field is required when the direction of discontinuities is unknown. The field polarization is usually tested by the Quantitative Quality Indicators (QQI). These indicators verify in which directions the field strength is adequate. If the field is indicated by QQI as a sufficient in all directions it is often called circular polarization, despite the fact it may not be really circular polarized. Measurements have shown that the polarization is elliptical at its best [1].The rotating magnetic field ideally consists of two perpendicular harmonic components of equal frequency and a ninety degrees mutual phase shift. In a presence of a nonlinear material (which is mostly the case) higher harmonics are generated. Moreover, heavy use of switching sources has changed power AC current waveform that it is no longer sinusoidal.Higher harmonic components are likely to change the magnetic field polarization nature. This paper investigates nonlinear effect and its impact on a polarization of magnetic field and MPI detection ability. It has been found that higher harmonic components may cause blind angles, eg. directions in which cracks are not likely to be detected. Examining the impulse of magnetic force affecting a particle, the total effect of higher harmonic components in MPI process is evaluated.

Název v anglickém jazyce

The effect of higher harmonic components on MPI process

Popis výsledku anglicky

Magnetic Particle Inspection (MPI) relies on magnetic forces driving small ferromagnetic particles. Such forces are caused by inhomogeneities (cracks) in ferromagnetic bodies perpendicular to magnetic field intensity. In order to detect defects in all possible directions it is essential to create rotating magnetic field tangential to the surface of the material under test. Such a field is required when the direction of discontinuities is unknown. The field polarization is usually tested by the Quantitative Quality Indicators (QQI). These indicators verify in which directions the field strength is adequate. If the field is indicated by QQI as a sufficient in all directions it is often called circular polarization, despite the fact it may not be really circular polarized. Measurements have shown that the polarization is elliptical at its best [1].The rotating magnetic field ideally consists of two perpendicular harmonic components of equal frequency and a ninety degrees mutual phase shift. In a presence of a nonlinear material (which is mostly the case) higher harmonics are generated. Moreover, heavy use of switching sources has changed power AC current waveform that it is no longer sinusoidal.Higher harmonic components are likely to change the magnetic field polarization nature. This paper investigates nonlinear effect and its impact on a polarization of magnetic field and MPI detection ability. It has been found that higher harmonic components may cause blind angles, eg. directions in which cracks are not likely to be detected. Examining the impulse of magnetic force affecting a particle, the total effect of higher harmonic components in MPI process is evaluated.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

20501 - Materials engineering

Projekt

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Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

NDT in Canada Conference Proceedings

ISBN

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ISSN

2561-2050

e-ISSN

2561-2050

Počet stran výsledku

6

Strana od-do

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Název nakladatele

Canadian Institute for Non-destructive Evaluation

Místo vydání

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Místo konání akce

Halifax

Datum konání akce

19. 6. 2018

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

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