Pulsed eddy current empirical modeling
نویسندگان
چکیده
The pulsed eddy current responses to varying material thickness and conductivity are modeled using an electrical circuit ideal transformer non-linear model. The Levenberg-Marquardt algorithm is used to curve fit the experimental signal to the model. The resulting synthetic signal is examined for its ability to preserve experimental signal features such as lift-off point of intersection (LOI), a pulsed eddy current signal feature used successfully in NDE of corrosion, cracks, thickness and conductivity measurements. The method is tested on specimens for its ability to reproduce inspection images using synthetic signals in lieu of experimental signals. This procedure conserves data storage space and allows rapid analysis of images using equations.
منابع مشابه
Compu1er Modeling of Pulsed Eddy-currents in Conducting Materials for Ndt Purposes
The numerical modeling of single frequency eddy-current phenomena based on the magnetic vector potential has been successfully applied to many NDT applications [1-3]. Despite the considerable wealth of sinusoidal eddy-current literature, the numerical modeling of pulsed eddy-currents has received little attention. Most of the recent finite element transient eddy-current NDT modeling [4,5] emplo...
متن کاملCorrosion Steel Inspection under Steel Plate Using Pulsed Eddy Current Testing
Pulsed eddy current inspection techniques were derived from the conventional eddy current testing technology, based on the fundamental principle of an eddy current coil, but using periodic ultrasound pulses. The authors first introduce the principle of pulsed eddy current inspection and some experimental measurement results using pulsed eddy current equipment. This technology can be applied to ...
متن کاملCoupled Transient Thermal and Pulsed Ec Modeling for Ndt of Materials Subjected to Laser Based Heat Treatment
The pulsed eddy current (PEC) technique is widely used to detect and quantify flaws in conducting plates .This method has been used to test materials subjected to heat treatment. Material properties such as conductivity show a marked change with temperature. As the heat diffuses into the material, the probe output changes owing to the changing material properties. Hence, it becomes difficult to...
متن کاملPulsed Eddy-Current Response to a Conducting Half-Space
Eddy-current nondestructive evaluation is commonly carried out using single frequency time harmonic excitations, but a pulsed excitation offers a simple and effective alternative. The pulse signals have been calculated for a probe coil whose current rises and falls exponentially, approximating a square wave when the exponential time constant is small. Predictions of the induced electromotive fo...
متن کاملAutomatic Classification and Characterization of Hidden Corrosion Using Pulsed Eddy Current Data
Detection and characterization of the material loss due to corrosion in aircraft fuselage joints plays an important role in life management of aging aircraft. Pulsed eddy current has been shown to effectively characterize hidden corrosion in lap splices. However, variation of the probe lift-off and interlayer gap can cause false indications or inaccuracy in quantification. This paper presents t...
متن کامل