Experimental setup for acoustic and mechanical characterisation of lightweight building elements

This study investigates the vibro-acoustic characterisation of lightweight building elements within an alternative test rig, developed in order to speed up the measurement procedure by reducing the size of the samples. Not so many years ago, building construction concerned mostly heavyweight and massive structures, although nowadays lightweight elements are often preferred. Sustainability and energy eciency requirements have contributed in the development and widespread use of newbuilding technologies and materials. In order to properly design acoustically comfortable buildings by using recently developed prediction models, such as the EN 12354 standards for example, it is necessary to accurately characterise each partition. A reliable characterisation of the elastic and damping properties of a certain building element is fundamental to determine the input data necessary for the simulation of its acoustics performance. This aspect is mostly underestimated and the designers often uniquely rely on database values. However, in order to apply simulation models to complex structures, such as inhomogeneous and non-isotropic elements or multilayer systems, it is indispensable to adopt homogenisation techniques and characterise the elastic and damping properties within the entire frequency range of interest. In this paper an experimental setup to investigate elastic and acoustic properties of lightweight panels, which are usually required as input data in prediction models, is presented. The test rig has been developed for a rectangular element with a surface area of approximately one square metre. One inhomogeneous plywood panel has been characterised, by measuring the plate response due to a mechanical excitation with accelerometers. The structures' elastic properties have been experimentally evaluated, by means of a wave correlation technique. Moreover the radiation eciency of the mechanically excited plate has been determined. The obtained results are presented, and the advantages and drawbacks of this approach are discussed.