Analytical model for mutual inductance between two rectangular coils in driver pickup mode for eddy current testing

2017 ◽  
Vol 33 (1) ◽  
pp. 20-34 ◽  
Author(s):  
Wu Dehui ◽  
He Tianfu ◽  
Wang Xiaohong ◽  
Su Lingxin
Keyword(s):  
Analytical Model ◽  
Eddy Current ◽  
Mutual Inductance ◽  
Eddy Current Testing ◽  
Current Testing

scholarly journals Analysis of Lift-Off Effect on Transmitter-Receiver Probe in Eddy Current Testing

2020 ◽  
Author(s):  
Qing Zhang ◽  
Xin Li ◽  
Guiyun Tian
Keyword(s):  
Analytical Model ◽  
Eddy Current ◽  
Signal To Noise Ratio ◽  
Ferromagnetic Materials ◽  
Eddy Current Testing ◽  
Probe Design ◽  
Deep Penetration ◽  
Current Testing ◽  
Straight Line ◽  
Lift Off

The Transmitter-Receiver Probe (TR probe), which has improved signal-to-noise ratio, deep penetration depth, and directional measurement is used in pulsed eddy current testing (PECT). Whereas, the lift-off effect on the TR probe is one of the main obstacles. The purpose of this paper is to analyze the lift-off effects on the TR probe and presents a feature for lift-off estimation. Firstly, an analytical model of a TR probe is given based on previous studies. Secondly, on the basics of the analytical model, the spectrum of the PECT signal is studied, and the lift-off effects on the TR probe are analyzed. Then, the lift-off effects under different coil distances are studied and a D Intersect Point (DIP) is proposed for the lift-off estimation. Results show that the TR probe can be used to reduce the lift-off effect for the non-ferromagnetic materials and the ferromagnetic materials. And both the DIP time and amplitude can be used for lift-off estimation. However, the DIP time is better, as its evolution curve with lift-off is a straight line with the same slope. The study is believed to be helpful for the TR probe design, the lift-off measurement, and the thickness assessment and defect quantification.

scholarly journals Analytical model for probe impedance using reflection and transmission theory in eddy current testing

2009 ◽  
Vol 58 (9) ◽  
pp. 5950
Author(s):  
Fan Meng-Bao ◽  
Huang Ping-Jie ◽  
Ye Bo ◽  
Hou Di-Bo ◽  
Zhang Guang-Xin ◽  
...  
Keyword(s):  
Analytical Model ◽  
Eddy Current ◽  
Eddy Current Testing ◽  
Reflection And Transmission ◽  
Current Testing

Evaluation of circumferential cracks in metal tubes based on a magnetic field response model of eddy current testing

2020 ◽  
Vol 62 (2) ◽  
pp. 91-97
Author(s):  
Feng Jiang ◽  
Shulin Liu ◽  
Shaojie Xin ◽  
Hongli Zhang
Keyword(s):  
Magnetic Field ◽  
Theoretical Model ◽  
Analytical Model ◽  
Eddy Current ◽  
Eddy Current Testing ◽  
Metal Tube ◽  
Destructive Testing ◽  
Current Testing ◽  
Field Response ◽  
The Magnetic Field

According to the characteristics of circumferential cracks on the inner surface of metal tubes, a magnetic field response method has been proposed and a mathematical analytical model for detecting the circumferential crack has also been established. The theoretical model, based on the magnetic field response, could be expressed as a series sum of trigonometric and Bessel functions. The relationship between the distribution of the magnetic field in the inner region of the metal tube and the geometrical size of the cracks is also analysed. The results show that the analytical model can effectively explain and analyse the variation of the surrounding magnetic field caused by the crack. The characteristic parameters of the crack, Br and Bz , which are extracted from the magnetic field, have certain quantitative recognition abilities. In addition, an increase in the thickness of the metal tube causes a larger range of magnetic field variations and is considered to be disadvantageous for detecting a change in the magnetic induction intensity that is a result of the crack. A theoretical model and research results contribute to the development of eddy current testing and improve the accuracy of the non-destructive testing and evaluation of metal tubes.

Probabilistic evaluation of detection capability of eddy current testing to inspect pitting on a stainless steel clad using multiple signal features

2020 ◽  
Vol 64 (1-4) ◽  
pp. 47-55
Author(s):  
Takuma Tomizawa ◽  
Haicheng Song ◽  
Noritaka Yusa
Keyword(s):  
Stainless Steel ◽  
Eddy Current ◽  
Pressure Vessels ◽  
Eddy Current Testing ◽  
Probability Of Detection ◽  
Current Testing ◽  
Multiple Signal ◽  
Signal Features ◽  
Inner Surface ◽  
Drill Holes

This study proposes a probability of detection (POD) model to quantitatively evaluate the capability of eddy current testing to detect flaws on the inner surface of pressure vessels cladded by stainless steel and in the presence of high noise level. Welded plate samples with drill holes were prepared to simulate corrosion that typically appears on the inner surface of large-scale pressure vessels. The signals generated by the drill holes and the noise caused by the weld were examined using eddy current testing. A hit/miss-based POD model with multiple flaw parameters and multiple signal features was proposed to analyze the measured signals. It is shown that the proposed model is able to more reasonably characterize the detectability of eddy current signals compared to conventional models that consider a single signal feature.

scholarly journals Research on Detection Mechanism of Weld Defects of Carbon Steel Plate Based on Orthogonal Axial Eddy Current Probe

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5515
Author(s):  
Linnan Huang ◽  
Chunhui Liao ◽  
Xiaochun Song ◽  
Tao Chen ◽  
Xu Zhang ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Eddy Current ◽  
Steel Plate ◽  
Difficult Problem ◽  
Eddy Current Testing ◽  
Detection Sensitivity ◽  
Detection Mechanism ◽  
Current Testing ◽  
Weld Defects ◽  
Lift Off

The uneven surface of the weld seam makes eddy current testing more susceptible to the lift-off effect of the probe. Therefore, the defect of carbon steel plate welds has always been a difficult problem in eddy current testing. This study aimed to design a new type of eddy current orthogonal axial probe and establish the finite element simulation model of the probe. The effect of the probe structure, coil turns, and coil size on the detection sensitivity was simulated. Further, a designed orthogonal axial probe was used to conduct a systematic experiment on the weld of carbon steel specimens, and the 0.2 mm width and 1 mm depth of weld defects of carbon steel plates were effectively detected. The experimental results showed that the new orthogonal axial eddy current probe effectively suppressed the unevenness effect of the weld surface on the lift-off effect during the detection process.

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