Damping of flexural vibrations in rectangular plates using the acoustic black hole effect

Abstract

Journal of Sound and Vibration, 329 (22), Additional Information:• AbstractThe reduction of flexural vibration in plate structures has been investigated using the recently reported acoustic black hole effect for flexural wave reflection in plates with the local thickness varying according to h(x) = x m and m ≥ 2. Since sharp edges of such plates (wedges) are always truncated before x = 0, the real reflection coefficients are relatively high, therefore the application of a small amount of damping is required to achieve large reductions in vibration amplitude. This paper presents a numerical model of a plate incorporating an acoustic black hole wedge, with predictions for vibration amplitudes. These are compared to equivalent experimental measurements for a range of applied damping layers. It is concluded that the above-mentioned power-law wedges can be used as effective vibration dampers in plate structures over a wide frequency range of interest.

Acoustic black holes: recent developments in the theory and applications

“…One of the types of structures that have been recently investigated at Loughborough University both theoretically and experimentally included plates or beams bounded by the attached power-law wedges, with the addition of small amounts of absorbing material at their sharp edges [24,25]. The above-mentioned wedges-like structures (see Fig.…”

Effect of geometrical and material imperfections on damping flexural vibrations in plates with attached wedges of power law profile

“…In the papers [13][14][15], the numerical modelling and experimental measurements of point mobilities in rectangular plates with attached power-law wedges and in circular plates with central tapered holes have been carried out. The results show that substantial damping of resonant peaks takes place in rectangular plates with attached wedges, whereas in circular plates with central tapered holes damping is not as large, which was expected since there was no focusing in this case.…”

Recent developments in the theory and applications of ‘acoustic black holes’

“…Among the structures that have been recently investigated at Loughborough there were plates or beams bounded by the attached power-law wedges, with the addition of small amounts of absorbing materials at their sharp edges [23,24]. The above-mentioned wedges-like structures (see e.g.…”