• This is the author's version of a work that was accepted for publication in AbstractAn 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 (V.V.K). 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 of quadratic shape (wedge) 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 a 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 2 confirm the existence of the acoustic black hole effect for flexural waves and demonstrate the possibility of its use in practice.

The present paper describes the results of the investigation of low and medium frequency vehicle interior noise carried out using simplified structural-acoustic models. Analytical, finite element (FE) and experimental studies are presented and compared. In particular, the analytical approach is based on the formula representing the interior acoustic pressure in terms of structural and acoustic normal modes. This procedure does not take into account the effect of the enclosed air on structural vibrations. The FE analysis considers structural vibration modes, interior acoustic modes, full structural-acoustic interaction and the resulting structure-borne noise. The above-mentioned analytical and numerical results are compared with each other, and both of them are compared with the experimental results obtained for the simplified reduced-scale vehicle model "QUASICAR" developed in Loughborough University. The comparisons demonstrate some specific features of the analytical and numerical approaches and outline the acceptable limits of simplification in modelling vehicle interior noise. Although this study is concerned with structure-borne vehicle interior noise, its results and conclusions could be of interest for a wider range of engineering problems, such as building acoustics and dynamics of thin shell structures.