Main Article Content
Nowadays, numerical modelling has become an interesting tool for determining impedance variations due to various conductive flaws in eddy current non-destructive evaluation systems. These kinds of defects, rarely treated in the published works, are taken into consideration in the modelling while introducing them as electrically conductive volumes with a finite electric resistivity. This step is very important since it permits to improve qualitatively several models developed so far by many authors whose consider the defect as loss of material only. However, in several applications, the defect can occur with a finite resistivity such as impurity, small burns and micro-solder. On the other hand, even though the defect appears with a loss of materials, some polluting materials can fill the affected region. Indeed, the volume of the initial defect will be completely or partially occupied by these conducting pollutant materials. For this reason, this contribution consists of studying the effect of physical and geometrical characteristics of this kind of defect on the differential sensor response. Furthermore, we shall explain the necessity of taking the defect electric conductivity as an important parameter in order to develop a reliable and accurate inverse method allowing a full characterization of conductive defects.