Next Article in Journal
Human Interaction Recognition Based on Whole-Individual Detection
Next Article in Special Issue
Conductivity Classification of Non-Magnetic Tilting Metals by Eddy Current Sensors
Previous Article in Journal
Automatic Anomaly Detection on In-Production Manufacturing Machines Using Statistical Learning Methods
Previous Article in Special Issue
Single-Coil Eddy Current Sensors and Their Application for Monitoring the Dangerous States of Gas-Turbine Engines
Article

Rotating Focused Field Eddy-Current Sensing for Arbitrary Orientation Defects Detection in Carbon Steel

by 1,2,*, 1 and 2
1
School of Mechanical Engineering, Xiangtan University, Xiangtan 411105, China
2
Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI 48824, USA
*
Author to whom correspondence should be addressed.
Sensors 2020, 20(8), 2345; https://doi.org/10.3390/s20082345
Received: 24 January 2020 / Revised: 9 April 2020 / Accepted: 18 April 2020 / Published: 20 April 2020
(This article belongs to the Special Issue Eddy Current Sensor)
This paper presents a rotating focused field eddy-current (EC) sensing technique, which leverages the advantages of magnetic field focusing and rotating magnetic field, for arbitrary orientation defects detection. The sensor consists of four identical excitation coils orthogonally arranged in an upside-down pyramid configuration and a giant magneto-resistive (GMR) detection element. The four coils are connected to form two figure-8-shaped focusing sub-probes, which are fed by two identical harmonic currents with 90 degrees phase difference. A finite element model-based study of arbitrary orientation defects detection was performed to understand the probe operational characteristics and optimize its design parameters. Probe prototyping and experimental validation were also carried out on a carbon steel plate specimen with four prefabricated surface-breaking defects. In-situ spot inspection with the probe rotating above the defect and a manual line-scan inspection were both conducted. Results showed that the probe has the capability of detecting defects with any orientations while maintaining the same sensitivity and the defect depth can be quantitatively evaluated by using the signal amplitude. Compared with the existing rotating field probes, the presented probe does not require additional excitation adjustment or data fusion. Meanwhile, due to its focusing effect, it can generate a strong rotating magnetic field at the defect location with a weak background noise, thus yielding superior signal-to-noise ratio. View Full-Text
Keywords: eddy current testing; rotating electromagnetic field; focusing coil; defect detection; signal-to-noise ratio; non-destructive testing eddy current testing; rotating electromagnetic field; focusing coil; defect detection; signal-to-noise ratio; non-destructive testing
Show Figures

Figure 1

MDPI and ACS Style

Xu, Z.; Wang, X.; Deng, Y. Rotating Focused Field Eddy-Current Sensing for Arbitrary Orientation Defects Detection in Carbon Steel. Sensors 2020, 20, 2345. https://doi.org/10.3390/s20082345

AMA Style

Xu Z, Wang X, Deng Y. Rotating Focused Field Eddy-Current Sensing for Arbitrary Orientation Defects Detection in Carbon Steel. Sensors. 2020; 20(8):2345. https://doi.org/10.3390/s20082345

Chicago/Turabian Style

Xu, Zhiyuan, Xiang Wang, and Yiming Deng. 2020. "Rotating Focused Field Eddy-Current Sensing for Arbitrary Orientation Defects Detection in Carbon Steel" Sensors 20, no. 8: 2345. https://doi.org/10.3390/s20082345

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop