Simulation analysis of lift off on an eddy current sensor array's output characteristics based on finite element method

2011 ◽  
Author(s):  
Du Jin-qiang ◽  
He Yu-ting ◽  
Ding Hua ◽  
Wu Liming ◽  
Shao Qing
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Eddy Current ◽  
Simulation Analysis ◽  
Current Sensor ◽  
Eddy Current Sensor ◽  
Lift Off ◽  
Output Characteristics ◽  
Element Method

Simulation Analysis of Conformable Substrate on an Eddy Current Sensor Array’s Output Characteristics Based on Finite Element Method

2011 ◽  
Vol 130-134 ◽  
pp. 2724-2728
Author(s):  
Jin Qiang Du ◽  
Yu Ting He ◽  
Hua Ding ◽  
Li Ming Wu ◽  
Qing Shao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Eddy Current ◽  
Sensor Array ◽  
Simulation Analysis ◽  
Current Sensor ◽  
Finite Element Models ◽  
Eddy Current Sensor ◽  
Output Characteristics ◽  
Couple Method

Finite element models of an eddy current sensor array are built up by electromagnetic-circuit couple method, and the influences of conformable substrate on sensor’s output characteristics are analyzed by those models. It is shown that the model contains the conformable substrate has almost the same output characteristics as the model without it, but the output amplitudes and phases of the former model are higher than the latter. Therefore we can simply the sensor as a single surface to facilitate the analysis, and then revise it to fit to the real sensor.

Simulation Analysis of an Eddy Current Sensor Array Based on Finite Element Method

2011 ◽  
Vol 299-300 ◽  
pp. 1072-1077
Author(s):  
Jin Qiang Du ◽  
Yu Ting He ◽  
Hua Ding ◽  
Hai Wei Zhang ◽  
Li Ming Wu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Eddy Current ◽  
Sensor Array ◽  
Simulation Analysis ◽  
Element Model ◽  
Current Sensor ◽  
Eddy Current Sensor ◽  
Output Characteristics ◽  
Couple Method

A finite element model of an eddy current sensor array is built up by electromagnetic-circuit couple method, and the influences of crack length and frequency on sensor’s output characteristics are analyzed by this model. It is shown that the model established in this paper is reasonable. There would be a change on amplitude and phase when a crack appears below the footprint of sensing coil in metal plane, and the amplitude and phase of sensor coil are increasing gradually as crack propagation. As frequency increased, the differences between the sensing coils’ output become obvious. However, the differences begin decreasing while the frequency above 3MHz approximately. These results will provide a reference for further research and application of the sensor.

Effect of Conformable Substrate Thickness on an Eddy Current Sensor Array’s Output Characteristics

2011 ◽  
Vol 335-336 ◽  
pp. 1503-1507
Author(s):  
Jin Qiang Du ◽  
Yu Ting He ◽  
Hua Ding ◽  
Hai Wei Zhang ◽  
Li Ming Wu
Keyword(s):  
Finite Element ◽  
Eddy Current ◽  
Sensor Array ◽  
Element Model ◽  
Current Sensor ◽  
Substrate Thickness ◽  
Eddy Current Sensor ◽  
Sensor Fabrication ◽  
Output Characteristics ◽  
Couple Method

A finite element model of an eddy current sensor array is built up by electromagnetic-circuit couple method, and the influences of conformable substrate thickness on sensor’s output characteristics are analyzed by the model. It is shown that the amplitude of sensing coils’ output would diminish as substrate thickness increased, besides, the discrepancies of sensing coils’ output also decrease when the substrate becoming thicker. Therefore tt is necessary to make the conformable substrate as thin as possible in sensor fabrication process to enhance the crack inspecting ability of the sensor.

Study on extraction of electrical runout in eddy current measurement using finite element method

2013 ◽  
Vol 228 (6) ◽  
pp. 1077-1086 ◽  
Author(s):  
Xiaolong Chen ◽  
Yanlong Cao ◽  
Zaiyu Lin ◽  
Jiangxin Yang ◽  
Xiaoqi Hu
Keyword(s):  
Finite Element ◽  
Relative Permeability ◽  
Imaginary Part ◽  
Eddy Current ◽  
Material Properties ◽  
Ferromagnetic Material ◽  
Current Sensor ◽  
The Real ◽  
Eddy Current Sensor ◽  
Lift Off

Electrical runout is a bottleneck problem of eddy current sensor, which is caused by the maldistribution/variation of material electromagnetic properties of measurement target. However, extraction methods of electrical runout in eddy current displacement measurement remain ambiguous. Here, a 2D finite element model for the influence analysis of conductivity and permeability of ferromagnetic material on coil impedance of eddy current sensor is reported, which will be beneficial for detecting material properties and guiding manufacturing process. The relationships between the real and imaginary part of coil impedance with the varied material conductivity, relative permeability and the lift-off, which indicates the detecting distance, are investigated. When the conductivity, relative permeability of ferromagnetic material and the lift-off vary within a certain range, the relationships between the real and imaginary part of coil impedance are all nearly linear. This paper further shows that the character of distribution of resistance and reactance in diagram under different material properties and same measuring distance is linear. Furthermore, these lines under different measuring distances are parallel. Also the character under different measuring distances and same material property is linear, but these lines under different material properties are diffuse with same intercept. Altogether, the study shows that this method based on redesign of signal processing and its circuit is feasible and instructive in separating electrical runout from the output of eddy current sensor.

Simplified Calculation Method of Planar Coil Impedance Considering the Eddy Current Distribution by Using Finite Element Method

2014 ◽  
Vol 792 ◽  
pp. 215-220 ◽  
Author(s):  
Hiroyuki Wakiwaka ◽  
Daisuke Ito ◽  
Kunihisa Tashiro ◽  
Hisashi Yajima ◽  
Yuji Manta ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Eddy Current ◽  
Calculation Method ◽  
Metal Plate ◽  
Current Sensor ◽  
Planar Coil ◽  
Simplified Calculation ◽  
Element Method ◽  
Simplified Calculation Method

Eddy current sensors have various uses. However, there are few studies which show theinfluence of a conductor on the impedance of a detector coil using theoretical formulae. This papershows a simplified calculation method for impedance of a planar coil while considering the influenceof eddy current. An eddy current distribution in a metal plate facing to planar coil was calculatedusing finite element method. It assumed the metal plate to be a one-turn coil that can change shape.Therefore, the impedance of a planar coil considering the influence of the eddy current can beestimated from an equivalent circuit. In addition, calculations were simplified by estimating mutualinductance between the planar coil and the metal plate from an area ratio. This simplified calculationmethod can estimate impedance with the same accuracy as finite element method. The calculatedvalue agrees to within ±2.44 % of the measured value. The computation time was shortened by 1/20.Therefore, it can be immediately estimated how each parameter of a planar coil or a target influencesthe characteristic of the eddy current sensor. This simplified calculation method is useful for anoptimum design of an eddy current sensor.

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