Multi-scale characterisations of materials and structures by ultrasonic methods
Résumé
The characterisation of materials or structures by using ultrasonic techniques is based on the analyses of wave propagation. These inspections reveal elastic material properties or defects presence in the structure. These last twenty years, many different experimental set-ups have been developed to improve the devices and to extend the frequency range investigations, as large as possible. The different methods of wave generation and detection can be based on the usual piezoelectric sensors, non-contact techniques using air-coupled transducers, and either microwave or laser radiation. This complementary array covers the frequency band from tens of KHz to hundreds of GHz and provides facilities to characterise materials and to detect defects from submicron dimension up to airplane size. From a theoretical point of view, a multifaceted perspective is required for interpreting and extracting a maximum of reliable data from the experiments that are performed with diverse physical and geometrical parameters. As a result, the material models under study can combine anisotropy, continuous heterogeneity, presence of inclusions, viscoelasticity, piezoelectricity, heat conductivity, acousto-optic and opto-acoustic interactions and electromagnetism. Characterization of materials and Non Destructive Testing are areas of application addressing the currently growing industrial demand for materials in aeronautics, transport and civil engineering.
Domaines
Acoustique [physics.class-ph]
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