An equivalent circuit description of two coupled vibrations

Abstract

Two adjacent mechanical systems usually affect each other. This is particularly noticeable if their resonance frequencies are almost equal. A simple way of describing this phenomenon, for second-order mechanical systems, is derived in this article. It is shown that the mechanical coupling can be described with the help of an ordinary electric equivalent circuit. The components in the equivalent circuit are easily measured electrically, for instance, with the help of piezoelectric and magnetostrictive devices, strain gauges or with an impedance meter. It is also shown how useful information can be extracted from measurements in a simple way. Predictions of the vibration amplitude of a second system, caused by a first system, can easily be made, if the values of the equivalent components are known. The behavior of the systems in the absence of the coupling can also be predicted from the (electric) measurements.