TY - THES A1 - Mayr, Andreas R. T1 - Vibro-Acoustic Sources in Lightweight Buildings N2 - The work reported in this thesis addresses the problem of structure-borne sound transmission in buildings. Vibrating sources, such as services plant and domestic appliances, transmit vibro-acoustic power, causing noise complaints by occupants in rooms removed from the source room. There is not yet an accepted practical method of predicting the installed power into floors or supporting walls, and thence the resultant sound pressure in rooms. This study concentrates on the prediction of the installed power from mechanical installations in lightweight buildings composed of framed and ribbed plates. To identify the characteristics of such receiver elements, a field survey has been undertaken, which involved measurement of the point and transfer mobilities of common wall and floor structures. It is shown that the range of measured values of receiver point mobility is surprisingly small and that the constructions investigated often displayed thin plate-like characteristics, with relatively small spatial variations in point mobility. These field measurements give support to the notion of averaging over contacts. This single equivalent receiver mobility has been assembled both from measured data and from the approximate method and then used in combination with single equivalent source data, to yield an approximate prediction of the installed power. The agreement obtained between the exact and approximate values allowed consideration of a practical implementation of the approximate prediction method, based on a reception plate method which yields the activity and mobility of the tested machine as single equivalent values. KW - Vibro-acoustic sources KW - Lightweight buildings Y1 - 2010 PB - Logos Verlag Berlin GmbH ER - TY - CHAP A1 - Gibbs, Barry A1 - Mayr, Andreas T1 - Structure-borne sound from machines in lightweight buildings. T2 - 15th International Congress on Sound and Vibration (ICSV15), July 2008, Daejeon, Korea N2 - A practical method is proposed for predicting the total structure-borne sound transmission from machines installed in lightweight buildings. The total structure-borne sound power is a function of the source activity and mobility, and the receiver mobility, at each contact and for each component of excitation. The data and computational requirements for prediction normally are large and are required to be in complex form for the cases where source mobility and receiver mobility are of the same magnitude. This can occur in lightweight framed buildings. However, manufacturers view their products as single entities and desire corresponding single values of source strength. They also desire simple measurement methods and the data obtained to be in octave or one-third octaves. A laboratory reception plate measurement procedure has been proposed which yields single equivalent values of source strength and source mobility. The source data, in combination with an estimate of the single equivalent value of receiver mobility, yields a simple prediction of the total installed power. The accuracy of the simple prediction depends on the spatial variation in contact conditions. For example, the receiver mobility over a joist is likely to be significantly lower than for positions between joists. Case studies are described for multiple contact sources on a timber-joist floor where the simple predictions are compared with exact values obtained from a full mobility formulation. KW - Structure-born sound KW - Lightweight buildings Y1 - 2008 ER - TY - CHAP A1 - Mayr, Andreas R. A1 - Gibbs, Barry T1 - On the use of a single equivalent receiver mobility in lightweight buildings. T2 - 19th International Congress on Acoustics 2007 (ICA 2007), Madrid, Spain, September 2007. KW - Lightweight buildings KW - Single equivalent receiver Y1 - 2007 ER - TY - CHAP A1 - Mayr, Andreas R. A1 - Gibbs, Barry A1 - Fischer, Heinz Martin T1 - Structure-borne sound transmission in lightweight buildings: Consideration of an equivalent single receiver mobility T2 - DAGA 2007, Deutsche Jahrestagung für Akustik, Stuttgart. KW - Sound tramsmission KW - Lightweight buildings Y1 - 2007 ER -