Conductivity Simulation for Material Characterisation by Eddy Current
M. Zergoug, A. Hammouda, A. Benchaala, CSC, Algeria
ABSTRACT
The sensitivity to defects and other parameters of control can be improved by the optimal choice of the probe. The Eddy Current NDT simulation can resolve the material characterisation problems. The principal rule of simulation is to explain the physical phenomena between the power source and the material testing. The approach is to determinate material conductivity simulation by using the diagram impedance and different variable parameters (Frequency, factor K,...). The testing probe realisation by eddy currents was satisfactory at the sight of control and testing results of coating samples. The fundamental parameters to keep in mind for a probe construction are to diminish the reluctance of the measure circuit. For the determination of the material conductivity, we opted for a physical approach based on the simulation. We noticed, in return for certain hypotheses, that the variation of the conductivity or the frequency in the diagram of impedance. In the first case, the simulation is valid for non-ferromagnetic materials, and it is necessary to saturate ferromagnetic samples in order to give back their near relative permeability of the unit. For the simulation of the conductivity, it would be interesting to generalise the measure of this parameter to ferromagnetic material without saturating this last, while working in the domain of Weiss. For it, a physical approach of the relative magnetic permeability and by following the simulation of the phase between parts activates, and reactive impedance is necessary. We have proceeded a control for samples with a different permeability. The simulation of this displacement would permit to measure the conductivity for ferromagnetic materials. The knowledge of conductivity allows to characterise metallurgical states of materials and develop NDT by eddy current.
Publication Source: 3nd International Conference on NDE in Relation to Structural Integrity for Nuclear and Pressurized Components, November 14-16, 2001, Seville Spain. Publisher: Tecnatom s.a. - [Homepage]
