oil and gas transmission pipelines are critical items of infrastructure in providing energy sources to regions and countries. steel pipes are commonly used which can be subject to both internal and external corrosion. this paper presents an advanced nondestructive inspection technique for detection of oil-gas pipeline corrosion defect. the pulsed eddy current (pec) method has been successfully ...

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 ...

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...

stress and residual stress are the main problems in the operating performance of materials. they are the principal causes of material failure and can affect life time of component. however measurement or predictions of them are typically difficult. two common non-destructive methods, x-ray diffraction and ultrasound are not reliable methods for subsurface residual stress measurements and destru...

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...

This paper reports a noncontact inspection method, using Pulsed Eddy Current (PEC) stimulated thermography, for the evaluation of the anisotropic dependency of electrical conductivity of steel exposed to tensile stress. This method combines microscope lens based thermography with PEC using a rectangular excitation coil, giving directional excitation, to infer the electromagnetic properties vari...

Abstrac t Pulsed eddy current (PEC) is a new technique of non-destructive material evaluation (NDE). In comparison with other eddy current techniques, PEC uses pulsed excitation that is characterized by wide frequency content and thus the response carries more complex information about a tested object. PEC method is used in many NDE common applications such as inspection of defects, measurement...

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...

Oil and gas transmission pipelines are critical items of infrastructure in providing energy sources to regions and countries. Steel pipes are commonly used which can be subject to both internal and external corrosion. This paper presents an advanced nondestructive inspection technique for detection of oil-gas pipeline corrosion defect. The Pulsed Eddy Current (PEC) method has been successfully ...