Derivation of an equivalent acoustic network of a circular drum membrane

Abstract

The drum is a mechano-acoustic system. The analysis of its characteristics and in most cases that of the membrane (mechanical system) is based on energy principles. However, we know that there are analogies between mechanical, acoustic and electrical systems. If the analogies are correctly made we can easily transform problems in one system to the other. It should be possible therefore to study the behaviour of drum membrane by methods and laws used in the theory of electrical circuits through the application of appropriate analogies. This paper presents a method for the derivation of an equivalent acoustic network of the drum circular membrane based on electrical circuit analogy. This is achieved by first obtaining the transverse displacement of the membrane through the use of Fourier-Bessel functions. The displacement is then processed to obtain the acoustic impedance of the membrane. In a companion paper, the model here was used to represent the membrane. The results compared favourably with experimental results available in the literature.

Journal of Applied Science, Engineering and Technology Vol. 3(1) 2003: 39-43