The effect of higher harmonic components on MPI process

Result code in 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>

Result on the web

<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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Result language

angličtina

Original language name

The effect of higher harmonic components on MPI process

Original language description

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.

Czech name

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Czech description

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Type

D - Article in proceedings

CEP classification

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OECD FORD branch

20501 - Materials engineering

Project

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Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2018

Confidentiality

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

Article name in the collection

NDT in Canada Conference Proceedings

ISBN

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ISSN

2561-2050

e-ISSN

2561-2050

Number of pages

6

Pages from-to

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Publisher name

Canadian Institute for Non-destructive Evaluation

Place of publication

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Event location

Halifax

Event date

Jun 19, 2018

Type of event by nationality

WRD - Celosvětová akce

UT code for WoS article

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