LASER GENERATION AND DETECTION OF ULTRASOUNDS: R&D ACTIVITIES AT ELECTRICITE DE FRANCE - OPUS Project

Our laboratory is involved in the development of non-conventional techniques for the non-destructive evaluation of metallic materials. Our technological and scientific developments in progress include -laser generation of US waves, -laser heterodyne interferometry for contactless detection of US waves. Concerning the inlerferometric contactless detection, we address the major drawback of this technique, the speckle effect due to the coherent scattering. We investigate some new approaches to overcome this problem. The main applications of these combine techniques, that we suggest, are: -on-line materials characterization (e.g. grain size evaluation in steel sheets) -damage measurements to evaluate the material degree of ageing