Thermal imaging of the structural damping induced by an acoustic black hole

Abstract

An Acoustic Black Hole (ABH) is a passive and efficient way to control the flexural vibrations of beams or plates. In its classical form, an ABH consists of a local reduction of the thickness of a structure according to a power law profile, associated with a thin viscoelastic coating placed in the thinnest region. A focalization and a wave trap effect occur, leading to a localized energy dissipation, which induces a local temperature increase. The objective of this paper is twofold. First, the goal is to develop an adequate experimental methodology capable of accurately mapping the small temperature variations induced by the local dissipation mechanism. Second, from the thermal standpoint, the goal is to provide experimental evidence of a local temperature increase associated with a damping effect in the case of an ABH beam. This paper thus describes a new kind of experimental methodology able to provide original data, bringing some new insight into the ABH physical understanding and the analysis of structural damping.