A new retroreflector named "quatriplan" based on the corner-cube principle, for advanced ultrasonic telemetry applications.

Telemetry consists in remotely detecting and locating an object. For applications in immersed structures as in nuclear primary vessel, ultrasonic waves are well adapted. Moreover, fixing a target on the structures of interest maximizes the signal-to-noise ratio and provides a reference point.

Acoustical properties of an immersed corner-cube retroreflector alone and behind screen for ultrasonic telemetry applications.

Ultrasonic telemetry measurements consist in remotely detecting and locating an object. To maximize the signal-to-noise ratio, a target may be used, positioned at a reference point. In this framework, the ultrasonic reflective characteristics of a corner-cube retroreflector (CCR) are investigated.

Multi-modal leaky Lamb waves in two parallel and immersed plates: Theoretical considerations, simulations, and measurements.

Leaky Lamb waves have the potential to be used to perform non-destructive testing on a set of several parallel and immersed plates. Short-time Fourier transform and two-dimensional Fourier transform have both been successfully used to measure the propagation properties: phase and group velocity, and leaky attenuation. Experimental measurements were validated by comparison between theory, experimentation and finite-element simulations (using comsol multiphysics software) in the case of one immersed plate in water.

Measurement of ultrasonic scattering attenuation in austenitic stainless steel welds: realistic input data for NDT numerical modeling.

Multipass welds made of 316L stainless steel are specific welds of the primary circuit of pressurized water reactors in nuclear power plants. Because of their strong heterogeneous and anisotropic nature due to grain growth during solidification, ultrasonic waves may be greatly deviated, split and attenuated. Thus, ultrasonic assessment of the structural integrity of such welds is quite complicated.

An experimental evaluation of two effective medium theories for ultrasonic wave propagation in concrete.

This study compares ultrasonic wave propagation modeling and experimental data in concrete. As a consequence of its composition and manufacturing process, this material has a high elastic scattering (sand and aggregates) and air (microcracks and porosities) content. The behavior of the "Waterman-Truell" and "Generalized Self Consistent Method" dynamic homogenization models are analyzed in the context of an application for strong heterogeneous solid materials, in which the scatterers are of various concentrations and types.

Ultrasonic wave propagation in heterogeneous solid media: theoretical analysis and experimental validation.

This research deals with the ultrasonic characterization of thermal damage in concrete. This damage leads to the appearance of microcracks which then evolve in terms of volume rate and size in the material. The scattering of ultrasonic waves from the inclusions is present in this type of medium.