KRYLOV, K.K. and WINWARD, R.E.T.B., 2005. Experimental evidence of the acoustic black hole effect for flexural waves in tapered plates. IN: Proceedings of the 12th International Congress on Sound and Vibration, Lisbon, Portugal, 11-14 th July.
A new efficient method of reducing edge reflections of flexural waves in plates or
bars based on the 'acoustic black hole effect' has been recently proposed and
described theoretically by one of the present authors  (see also [2-4]). The method
utilises a gradual change in thickness of a plate or bar, partly covered by thin damping
layers, from the value corresponding to the thickness of the basic plate or bar (which
is to be damped) to almost zero. The present paper describes the results of the
experimental investigation of the damping system consisting of a steel plate (wedge)
of quadratic shape covered on one side by a strip of absorbing layer. The results of
the measurements of point mobility in such a system show that for the wedge covered
by an absorbing layer there is a significant reduction of resonant peaks, in comparison
with the uncovered wedge or with the covered plate of constant thickness. Thus, the
measurements confirm the existence of the acoustic black hole effect for flexural
waves and demonstrate the possibility of its use in practice.