2002

Aatola, Seppo

Design of quiet machines and vehicles requires quantitative data of source strengths of sound and vibration sources. In addition mechanical mobility of structures and sources is needed for the estimation of vibrational power transmission from sources to receiving structures. These data are important if energy based methods are used in the estimation of sound and vibration characteristics of machines or vehicles. In this state-of-the-art literature review basic concepts of mechanical impedance and mobility of elements is discussed. Also impedance, mobility and four-pole parameters are included. Thereafter the important issue of characterization of structure-borne sound sources is considered. Methods for the determination of the structure-borne sound power transmission from machines and applications are presented. Special emphasis is given to applications in the ship context. In practise important power transmission through vibration isolators and measurement techniques are reviewed. Finally research and test facilities of vibration isolators in some countries are presented.