TY - CHAP A1 - Mayr, Andreas R. A1 - Gibbs, Barry A1 - Fischer, Heinz Martin T1 - On force- and moment mobilities of a timber joist floor T2 - 35th German Annual Conference on Acoustics (DAGA), Rotterdam, March 2009. N2 - In wood framed buildings, floors are formed by fastening wood sheathing to joists spaced at a regular interval. The sheathing is typically fastened to the joist using screws so the resulting system is a complicated periodic point-connected plate-rib structure. It is shown that the point force mobility varies significantly with position. A machine installation generally is close to discontinuities, such as at: floor edges, joist-screw locations, joints between the sheathing plates, and due to workmanship. In such cases, moment excitation might become important at some frequencies and the neglect of moments a priori can ead to inaccurate prediction of the total emission. This paper presents measured point moment mobilities with respect to the distance to discontinuities for a timber joist floor where a single layer of chipboard forms the sheathing. It is shownthat the measured point moment mobility indicates an infinite plate behaviour. This includes for positions above a joist but between screw positions. To determine the relative contribution of moments and perpendicular forces to the total structure-borne sound power, case studies of two sources, a fan unit and a whirlpool bath, are described, for various locations on a timber joist floor. KW - Force- and moment mobilities KW - Timber joist floor Y1 - 2009 ER - TY - JOUR A1 - Mayr, Andreas R. A1 - Gibbs, Barry T1 - Point and transfer mobility of point-connected ribbed plates JF - Journal of Sound and Vibration N2 - The work reported in this paper addresses the problem of structure-borne sound transmission between vibrating sources and ribbed-plate receiver structures. Vibrating sources, such as pumps, motors, fans, etc., transmit vibro-acoustic power, causing noise complaints by occupants in cars, trains, aircraft, buildings and/or material fatigue and damage. The transmission process is complicated in that sources transmit power through several contacts and by up to six components of excitation at each contact. The structure-borne sound power is a function of source activity, source mobility and receiver mobility, and all three quantities must be known to some degree. For non-homogeneous receiver structures, such as thin-plate cavity constructions or lightweight framed constructions, the sheathing plates are typically fastened to the framing members using bolts, screws or spot-welded joints. Hence the resulting system is a point-connected ribbed plate structure and the receiver mobility is expected to vary significantly with position. Since measured receiver data seldom is available for prediction purposes, a method of estimating the point and transfer mobility of point connected ribbed plates is required. In this paper, an approximate approach, based on substitution forces, is described. The model uses infinite beam and infinite plate behaviour as input quantities. Estimates of point and transfer mobility are compared with measured results using a timber joist floor construction as an example. KW - Point and transfer mobility KW - point-connected ribbed plates Y1 - 2011 IS - 330 (2011) SP - 4798 EP - 4812 ER - 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 R. T1 - Estimates of mobility for prediction of structure-borne sound transmission in buildings T2 - 19th International Congress on Sound and Vibration, ICSV19, Vilnius, Lithuania, July 2012. N2 - This paper aims to provide a practical approach to the prediction of structure-borne sound power of mechanical installations in buildings. For structure-borne power, two source quantities, activity and mobility, are required, in combination with one receiver quantity, the receiver mobility. The source activity, in the form of free velocity or blocked force, is usually measured. For source mobility and receiver mobility, estimates, based on simple expressions, can provide a useful starting point. Also, machine bases may be categorised as: compact, plate-like, flanged or framed. Receiver structures, floors and walls, may be categorised as: plate-like, ribbed plate or framed plate. The estimates of source mobility are based on the rigid body value, the characteristic plate mobility and the fundamental plate frequency. For ribbed and framed plate structures, the mobility will vary with location, but again simple estimates of mobility, based on characteristic values and distance from the ribs, are possible. KW - Structure-born sound transmission KW - Estimates of mobility Y1 - 2012 ER - TY - JOUR A1 - Mayr, Andreas R. A1 - Gibbs, Barry T1 - Single equivalent approximation for multiple contact structure-borne sound sources in buildings JF - Acta Acoustica unitet with Acoustica N2 - The work reported in the paper addresses structure-borne sound transmission between multiple contact sources and non homogeneous plate receiver structures. This study concentrates on a practical method of predicting the installed structure-borne sound power from mechanical installations in lightweight buildings. The structure-borne sound power is a function of source activity, source mobility and receiver mobility, and all three quantities must be known to some degree. It is rarely practical to consider all transmission paths individually and in detail, and therefore, reduced data sets and less computationally demanding procedures are proposed. The paper examines how source data can be used to assemble single equivalent values, using spatial averages and magnitudes. Single equivalent values of receiver mobility also are proposed for lightweight, point-connected ribbed plate constructions. In case studies, the single equivalent values are used for predicting the structure-borne power in the installed condition. KW - Single Equivalent Approximation KW - Contact Structure-Borne Sound Sources in Buildings KW - Sound transmission Y1 - 2012 IS - 98 (2012) SP - 402 EP - 410 ER - TY - CHAP A1 - Mayr, Andreas R. T1 - Schallemissionen gebäudetechnischer Anlagen im Holzbau T2 - HolzBauSpezial Akustik & Brandschutztage 2013, Bad Wörishofen N2 - Vor dem Hintergrund des Klimawandels ist die Nachhaltigkeit von Wohngebäuden von enormer Bedeutung für die Gesellschaft des 21sten Jahrhunderts. Niedrigenergie-und Passivhauskonzepte können entscheidend dazu beitragen, den Energieverbrauch in Deutschland maßgeblich zu reduzieren. Diese Konzepte erfordern neue Bauweisen und energieeffiziente gebäudetechnische Anlagen, insbesondere Heizungsanlagen, Wärmepumpen und Lüftungsanlagen. Zusätzlich zur Energieeffizienz wird aber bei modernen Gebäuden ein hoher Wohn- und Arbeitskomfort gefordert und geschuldet. Diesbezüglich ist der bauliche Schallschutz zu einem wesentlichen Qualitätskriterium von Wohngebäuden geworden. Der beim Betrieb von gebäudetechnischen Anlagen erzeugte Lärm wird zunehmend als Problem wahrgenommen, das die Wohnqualität, das Wohlbefinden und damit verbunden die Gesundheit negativ beeinträchtigen kann. Durch die permanente Lärmbelästigung am Arbeitsplatz, durch Verkehr etc. ist die Erholung von Lärmeinwirkungen im eigenen Wohnbereich unerlässlich und lässt der Nachhaltigkeit des baulichen Schallschutzes eine große Bedeutung zukommen. Dieser kann momentan aufgrund fehlender Planungswerkzeuge für die von gebäudetechnischen Anlagen ausgehenden Schallimmissionen nicht gewährleistet werden. Im Rahmen eines aktuellen, kooperativen Forschungsvorhabens der Hochschule Rosenheim und der Hochschule für Technik Stuttgart soll dieser Missstand beseitigt werden,indem aufeinander abgestimmte Mess-und Prognoseverfahren für die Körperschallerzeugung und Schallübertragung gebäudetechnischer Anlagen im Massivbau sowie im Holz- und Leichtbau erarbeitet, validiert und Anwendern bereitgestellt werden. Damit soll ein vollständiges Instrumentarium geschaffen werden, mit dem die Geräusche gebäudetechnischer Anlagen unter besonderer Berücksichtigung ihrer Körperschalleigenschaften von der Quelle über die Übertragung im Gebäude bis zum Einwirkungsort geschlossen beschrieben werden können. Die Methoden sollen den Anlagenhersteller für die Charakterisierung der Schallquellen und deren schalltechnische Optimierung zur Verfügung stehen und sollen von den Gebäudeplanern als Prognoseinstrument für die schalltechnische Planung und Auslegung genutzt werden können. Dies ist ausgesprochen anspruchsvoll, da gebäudetechnische Anlagen in vielen Fällen vor allem Körperschallquellen darstellen, deren physikalische Beschreibung aufgrund von Wechselwirkungen zwischen Quellen und Empfangsstrukturen ungleich komplizierter ist als die von Luftschallquellen. So ist die Körperschallerzeugung und -übertragung im Massivbau bekanntermaßen völlig unterschiedlich gegenüber den im Holzbau vorliegenden Bedingungen. Dies erfordert eine separate Betrachtung der Anrege- und Übertragungsmechanismen für beide Gebäudearten und bedingt die Kooperation der HFT-Stuttgart (spezialisiert auf Massivbau) und der HS Rosenheim (spezialisiert auf Holz und Leichtbau). Durch die Beteiligung von Unternehmen aus der gewerblichen Wirtschaft wird zudem sichergestellt, dass die aktuellen Bedingungen des Bauwesens Berücksichtigung finden und die praktische Umsetzbarkeit der Lösungen gewährleistet ist. KW - Schallemissionen KW - Holzbau Y1 - 2013 ER - TY - CHAP A1 - Schöpfer, Fabian A1 - Hopkins, Carl A1 - Mayr, Andreas R. A1 - Schanda, Ulrich T1 - Structure-borne sound propagation across a double leaf timber-frame wall T2 - 22nd International Congress on Sound and Vibration, ICSV22, Florence, Italy, July 2015. N2 - With the increasing mechanization of buildings, it is necessary to be able to predict both the structure-borne sound power input from building machinery and the subsequent propagation of structure-borne sound in the building. This paper considers lightweight constructions and describes the results of an experimental study in the laboratory on a T-junction that was constructed from a timber joist floor and two double leaf timber-frame walls. The focus in this paper is on the vibrational behaviour of one of the timber-frame walls. To assess the vibration pattern and the propagation of structure-borne sound, the surface velocity levels were measured on a grid on both leaves of the wall with point force excitation on one side. This grid allowed calculation of structural intensity vectors. The influence of elements such as the timber studs and tongue and grooved joints between the boards were apparent in different frequency regions. Experimental modal analysis was carried out using measurements on both leaves of the wall, giving information about the coupling in different frequency regions. The results give insight into how such a timber-frame wall could be modelled using statistical energy analysis. KW - Double-leaf timber-frame wall KW - Structure-borne sound propagation Y1 - 2015 ER - TY - CHAP A1 - Mayr, Andreas T1 - Schallschutz mit der neuen DIN 4109, Was hat sich im Bauteilkatalog Trockenbau geändert? T2 - Das Forum 2017 - Zukunft Trockenbau Ausbau, Berlin, Deutschland, September 2017. N2 - Die DIN 4109 regelt die Anforderungen an den Schallschutz in Gebäuden sowie den Nachweis der Einhaltung dieser Anforderungen. Im Juli 2016 erschien die komplett überarbeitete und neu strukturierte „neue“ DIN 4109. Im Vortrag werden wesentliche Änderungen, die neuen Rechenverfahren und die relevanten Bauteilkataloge kurz erläutert. Änderungen, die sich speziell für die schalltechnische Planung und Ausführung des Trockenbaus ergeben, werden anhand von praktischen Beispielen aufgezeigt. Damit soll ein Gefühl für Möglichkeiten und Grenzen in der Anwendung der neuen Norm vermittelt werden. KW - Trockenbau KW - Schallschutz KW - Bauteilkatalog Y1 - 2017 ER - TY - CHAP A1 - Schöpfer, Fabian A1 - Mayr, Andreas R. A1 - Schanda, Ulrich A1 - Bayer, Jeremias T1 - Analysis of measured transmission functions in timber buildings T2 - Proceedings of Forum Acusticum 2023 Y1 - 2023 ER - TY - CHAP A1 - Schöpfer, Fabian A1 - Mayr, Andreas R. A1 - Schanda, Ulrich A1 - Nusser, Bernd A1 - Arnold, Jörg A1 - Vogel, Albert A1 - Völker, Conrad T1 - Entwicklungen bei der Prognose von Geräuschen aus gebäudetechnischen Anlagen T2 - 12. Bauphysiktage 2024 KW - Körperschall KW - Normung KW - Körperschallquellen KW - Installationen Y1 - 2024 ER -