Keywords: fibre fluctuation, maximum tension, compress modulus, sound absorption coefficient, fibrous material, acoustic behaviour, porous materials, elastic sound absorption
Elastic sound absorption theory of fibrous material
Because of the complexity of classical sound absorption theory's expressions, it is difficult to obtain physical insight into the acoustic behaviour of porous materials and to determine the dominant mechanism for sound absorption for a given material at a given frequency. Alternatively, there are very simple expressions. A new theory has been put forward that fibrous material absorbs sound by the fibre's fluctuation. This theory has been justified by the equation obtained from the vibration analysed in this paper as well as the empirical sound absorption formula of fibrous material in the author's previous paper.