Conception de multicapteurs à courants de Foucault et inversion des signaux associés pour le contrôle non destructif

The growing complexity of industrial processes and manufactured parts, the increasing need of safety in service and the will of life span optimization, require more and more complex quality evaluations to be set up. Among the different anomalies to consider, submillimetric breaking surface notches have to be subject to special care. Indeed, it often constitutes a start to larger notches, which can cause destruction parts. Penetrant testing is nowadays widely used for that kind of defect, owing to its good performances. Nevertheless, it should be eventually dropped because of environmental norms. Among the possible substitution solutions, the use of eddy currents (EC) for conductive parts is a reliable, fast and inexpensive alternative. The study is about the conception and the use of multielements EC probe structures featuring microsensors for non destructive testing of surface breaking defects. A methodology has been established in order to develop such structures and to compare their performances within the framework of submillimetric surface breaking notch research. These structures has been employed for calibrated notches evaluation with a specific acquisition bench. Original detection and defect characterization algorithms have been designed and implemented on acquired signals. The most efficient structure has been determined, the notch detection quality has been quantified, and the geometric characteristics of notches has been estimated.