Variation of Eddy Current Density Distribution and its Effect on Crack Signal in Eddy Current Non-Destructive of Testing
The paper deals with variation of eddy current density distribution along material depth and investigates an effect of the variation on a crack signal in eddy current non-destructive testing. Four coaxial rectangular tangential coils are used to induce eddy currents in a tested conductive object. Th...
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| Format: | Article |
| Language: | English |
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VSB-Technical University of Ostrava
2006-01-01
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| Series: | Advances in Electrical and Electronic Engineering |
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| Online Access: | http://advances.utc.sk/index.php/AEEE/article/view/461 |
| Summary: | The paper deals with variation of eddy current density distribution along material depth and investigates an effect of the variation on a crack signal in eddy current non-destructive testing. Four coaxial rectangular tangential coils are used to induce eddy currents in a tested conductive object. The exciting coils are driven independently by phase-shifted AC currents; a ratio of amplitudes of the exciting currents is continuously changed to vary the distribution of eddy current density along material depth under a circular pick-up coil positioned in centre between the exciting coils. Dependences of a crack signal amplitude and its phase on the ratio are evaluated and special features are extracted. It is revealed that the dependences are strongly influenced by depth of a crack, and thus the extracted features can enhance evaluation of a detected crack. |
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| ISSN: | 1336-1376 1804-3119 |