Propagation of structure-borne sound in lightweight gypsum board walls

prEN ISO 10848 describes two different methods to measure the vibration reduction index Kij of junctions of building elements. Both methods are applicable to junctions of heavy, monolithic building elements, but only the indirect method that uses airborne sound seems to be practical for junctions of lightweight, assembled building elements, like framed gypsum board walls, so far. In the scope of a current research project at Eindhoven University of Technology to adopt the so-called direct method that is based on the measurement of structure-borne sound to junctions of such kind of elements, basic research is carried out at framed gypsum board walls to characterize the structure-borne sound propagation and the dynamic response of lightweight, assembled structures. Two in its geometry identical walls – the first one with a metal frame and the second one with a wooden frame – are built stepwise and also changes are made in the structure to determine the way structure-borne sound propagates in this type of elements as well as to find construction details that have influence on it. According to the frequency range different measurement techniques, like experimental modal analysis, power balance measurements and wave number measurements, have been applied to investigate the dynamic behaviour itself and to measure the material properties of the assembled structures in situ. The obtained knowledge will be used to find an appropriate analytical model of the structure and finally to describe appropriate conditions for the application of the direct-method of prEN ISO 10848