Multilayered Tubular Structures (MTS) such as pipeline are widely employed in such industrial fields as nuclear energy, petroleum, etc. It is vital to non-destructively evaluate MTS periodically before catastrophic accidents take place. As one of the advanced Electromagnetic Nondestructive Evaluation (ENDE) techniques, Pulsed Eddy Current Testing (PECT) has been found advantageous over the other ENDE methods regarding evaluation of integrity of MTS. In this paper, a fast forward model of PECT inspection of MTS is proposed based on the analytical modeling, namely the Extended Truncated Region Eigenfunction Expansion (ETREE). The closed-form expressions of PECT signals of 3D magnetic field and coil Electromotive Force (EMF) have been formulated. The proposed model has been verified by Finite Element Modeling (FEM) and experiments. The advantages of the model in terms of high computational speed and accuracy have been identified.

Pulsed Eddy Current Testing (PECT) is one of the advanced Electromagnetic Nondestructive Evaluation (ENDE) technology. In applications for crack detection and evaluation, rectangular probes are found superior to the cylindrical ones in terms of the directional characteristics and capability of creating uniform eddy current distributions. In this paper, in a bid to investigate the influence of parameters of a rectangular probe on inspection sensitivity and seek the optimal probe structure, a numerical model for conductivity/defect assessment with a rectangular probe is built up by using Comsol. Following this, experiments on flaw evaluation are undertaken by using the probe with the optimal parameters found in Finite Element Modelling (FEM). Through simulations and experiments, it can be seen that the rectangular probe with dimensions in the proportion of 2:1:1.5 (length:width:height) is optimal for conductivity evaluation.

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