Visualization of travelling waves propagating in a plate equipped with 2D ABH using wide-field holographic vibrometry

This paper presents a method for wide-field vibrometry based on high-speed digital holographic interferometry. We demonstrate the possibility of measuring transient vibrations of structures at 100 kHz frame rate when providing 46600 quantitative data on 380 cm2 rectangular spot at the object surface. Investigation of travelling acoustic waves propagating in alloy plate equipped with a two-dimensional acoustic black hole (ABH) is considered. Such a structure leads to localized vibrations of high amplitude and constitutes a good candidate for methodology testing. The wave front is generated by a short shock with duration about 50 μs? The time sequence of the vibration field obtained after the shock is depicted and exhibits the propagation of the wave front in the plate and inside the ABH. It follows that the observation of the modification of the wave propagation can be observed at very short time scale. The modification of the wave front due to the gradient in elastic properties related to the ABH area is also highlighted.