Effects of the interface roughness in metal-adhesive-metal structure on the propagation of shear horizontal waves.

The influence of the interface roughness in a three-layer metal-adhesive-metal structure on the propagation of shear horizontal waves and more particularly on the transmission coefficient versus the frequency is studied in the particular case of a periodic grating of triangular grooves. For given phonon frequencies, the interaction of an incident shear horizontal mode with the periodical grating gives rise to a retro-converted mode. A numerical finite element simulation permits us to predict the existence of the phonon mode in the three-layer structure and to obtain the evolution of the transmission coefficient around the phonon frequency.

Use of shear horizontal waves to distinguish adhesive thickness variation from reduction in bonding strength.

The capability of shear horizontal (SH) guided waves, to evaluate geometrical imperfections in a bonding layer, is investigated. SH waves are used in a three-layer structure in which the adhesive layer has variable thickness. It is proven that the SH waves are adapting to the local thickness of the adhesive layer (adiabatic waves).

Propagation of Lamb waves in an immersed periodically grooved plate: experimental detection of the scattered converted backward waves.

Guided waves propagation in immersed plates with irregular surfaces has potential application to detection and assessment of the extent, depth and pattern of the irregularity. The complexity of the problem, due to the large number of involved parameters, has limited the number of existing studies. The simplest case of irregularities of practical interest is the two-dimensional corrosion profile.

Study of the resonances of periodic plane media immersed in water: theory and experiment.

The paper deals with the study of the resonances of 1D periodic media composed of N elementary cells formed with two perfectly bonded layers which exhibit a high acoustic impedance contrast. In the case of a periodic bilayer structure constituted of a fluid layer and an elastic plate, it was shown in previous theoretical works that additional modes appear compared to those of a single plate. These are called structure modes.

Inverse problem for the geometry profile determination of waveguides with varying section using adiabatic behavior of guided waves.

The aim of this work is to obtain the geometry profile of a waveguide of continuous varying section, by inversing the experimental data. This determination is based on the use of the adiabatic behavior of guided waves. The geometry profiles obtained are in good agreement with the exact ones.

Determination of epoxy film parameters in a three-layer metal/adhesive/metal structure.

The aim of this work is to propose a method to determine the elastic parameters and the thickness of a thin epoxy film located inside a 3-layer aluminum/epoxy/aluminum structure, based on ultrasonic measurements. This study is conducted at low frequencies, to allow the vibration of the whole structure. First, the direct problem is addressed.