We developed a highly integrated, Field Programmable Gate Array (FPGA)-based digital multi-frequency eddy current platform which is capable of detecting surface breaking and subsurface cracks in non-magnetic plates. Excitation signal generation, receiving signal demodulation, and USB communication were all implemented inside a Xilinx FPGA (Spartan III). Multi-frequency test results provide rich...

This paper presents an inverse problem methodology in the domain of non-destructive testing, and more precisely eddy-current testing. Our objective is to use a precise but expensive-to-evaluate model of the electromagnetic induction phenomenon in a conductive material and to estimate the characteristics of a flaw by minimization of a regularized criterion with the Expected Improvement (EI) glob...

Exist forms and criticalities of disfigurements of marine engines were studied from main propulsive engine, auxiliary facility and hull. Eddy current Non-destructive testing method was brought forward to disfigurement inspection of marine engines with advantages such as celerity and nicety. Cracks, as one form of disfigurements, testing of marine engines were demonstrated in detail, and the dev...

A perturbation method is used to solve eddycurrent testing problems for a flaw of arbitrary shape situated in a conducting half-space when the electric conductivities of the flaw and the surrounding medium are nearly the same. A general formula for the change in impedance is obtained. Examples of cylindrical flaws of finite length and spherical flaws are given. Detailed numerical results are gi...

− This paper proposes an eddy-current nondestructive weld testing solution that uses a sensing probe including an excitation coil and a giant magneto-resistance sensor. The testing system control and the acquisition tasks are performed using a PXI system that includes a sinusoidal signal generator, a data acquisition module and a XY scanning stage control interface. For different positions of t...

This study proposes an investment for the evaluation of fatigue cracks by eddy current testing (ECT). Fatigue cracks (FC) manufactured on SUS316 plates are detected using ECT. Inverse analysis is applied to the ECT signals and both crack depth and length are estimated. Two models are applied, one is the EDM model without conductivity, and the other is the SCC model with partial conductivity. Th...

Control by eddy current is one of techniques that’s very used in nondestructive evaluation of materials .These processes find an application significant in the determination of the mechanical and metallurgical parameters of materials. The object of this work is to carry out an analysis of the residual stresses in the material created by external solicitations and analysed by eddy currents as a ...