Eddy current examination of carbon fibres in carbon-epoxy composites and Kevlar (2024)

NDT & E International, 2015

In the present paper we propose the development of a new method of ultrasound and eddy current data fusion using the theory of evidence given by Dempster and Shafer.

Nondestructive Evaluation of Materials and Composites V, 2001

This work aims at presenting two electromagnetic methods for non-destructive evaluation of delaminations in graphite- epoxy composites: the eddy current holography and the measurement of field reflected by delamination. The obtained results permit to get delamination images that are compared to the results obtained by ultrasonic C-scan procedure which is considered as reference method.

Advanced Electromagnetics, 2019

In this paper, an iterative technique, employing the T formulation associated with the finite element method, based on Maxwell's equations and the Biot-savart law, is used for analyzing the density of eddy currents in composite carbon fiber reinforced polymer (CFRP) materials. For this purpose, a code has been developed for solving an electromagnetic 3D non-destructive evaluation problem. This latter permits the characterization of this CFRP and determinate of fibers orientation using the impedance variation which is implanted in polar diagram. Firstly, the obtained results are compared with those of the analytical model. This comparison reveals a high concordance which proves the validity of the proposed method. Secondly, three different applications are shown for illustrating the characterization of unidirectional, bidirectional and multidirectional piece using a rectangular coil plotted in normalized impedance diagram.

Proceedings of the 2020 International Conference on Quantitative InfraRed Thermography, 2020

IEEE Transactions on Magnetics, 1996

Studies in Applied Electromagnetics and Mechanics, 2020

Carbon Fiber Reinforced Polymer (CFRP) materials are widely used in aerospace due to their low weigh to strength ratio. Non-destructive Testing (NDT) Techniques becomes a necessity with increasing use of CFRP materials. Induction Thermography is a new NDT technique that can be exploited as a promising fast and global control. However, the detection of typical flaws in carbon composites such as delamination, fibers rupture and impact damages need to be further investigated in order to optimize the technique. Optimization can be done in the test configuration level and by the use an appropriate image technique. In this paper Eddy Current Pulse Compression Thermography (ECPuCT) is used to detect impact damages on CFRP materials. The Principal Component Analysis (PCA) based image processing technique is used to detect and visualize impact damage area from transient thermal images. Flaw detection results using experimental measures will be shown and discussed.

The European Physical Journal Applied Physics, 2018

This paper proposes a contactless method for the identification of the electrical conductivity tensor of a carbon fiber composite materials plate using a rotating magnetic field and multi-coil eddy current sensor. This sensor consists of identical rectangular multi-coil, excited by two-phase sinusoidal current source in order to generate a rotating magnetic field and to avoid the mechanical rotation of the sensor. The fibers orientations, the longitudinal and transverse conductivities in each ply of carbon fiber composite material plate were directly determined with analysis of the impedance variation of each coil as function of its angular position. The inversion process is based on the use of artificial neural networks. The direct calculation associated with artificial neural networks makes use of 3D time-harmonic finite element method based on the A, V–A formulation.

Nucleation and Atmospheric Aerosols, 2012

Clad material is manufactured by creating a metallurgically bonded between few metals. The most important advantage of the materials is that the end product combines the superior properties of each component. A tested sample is commonly used for underwater petroleum pipelines. The sample consist of two metals: carbon steel, and Inconel. The aim of this paper is to present a massive multi-frequency excitation and spectrogram eddy current method for detection of surface cracks and dissections in clad materials. The system consists of a small differential eddy current transducer and four subsystems: a scanner, an excitation subsystem, a data acquisition subsystem and a controlling computer. The signal measured during transducer movement can be presented in the form of spectrogram. Properties of the spectrograms can be used for defect’s detection and identification. The experimental verification is done and selected results are presented.

Advances in Acoustics and Vibration, 2009

Journal of Intelligent Material Systems and Structures, 2010

Sensor Actuator a Phys, 2008

Due to richness of frequency content and robustness of anti-interference, pulsed eddy current testing of cracks in conductive materials attracts great interests. The objective of this study is to identify the surface and subsurface cracks that probably extends in all directions with pulsed eddy current probe. Based on the principle that cracks crossing the eddy current path with a right angle help PEC probe to gain the highest sensitivity, some probes with improved structures are developed to detect cracks in all directions. First, the structures of probes are described and their detection mechanisms are deduced. Then, experiments are carried out to verify probes’ performance. Comparison and further analysis are also derived with experimental results.

Sensors, 2015