SILENT TIMBER BUILD - modelling acoustic characteristics of timber structures

In year 2017 the WWN+ project "Silent Timber Build" is finishing. The project focused on studying timber structures with regard to their sound insulation characteristics, both airborne sound insulation and impact sound insulation. The aim is to develop calculation models (and / or to provide input to standardized models) for various timber structures available in Europe but also to facilitate future optimization of buildings using wood as structural bearing system. Divided into several subprojects, an efficient managing of the project was possible. In one part of the project, current timber structures are "grouped", considering their acoustical behaviour and their various compositions. Another part of the project was to use the grouping in order to develop and refine general prediction models by using FEM in combination with an SEA software that was included in the project from start. Throughout the project, the software was refined and adapted to typical building structures and groups. By comparing laboratory measurement results with calculated results, improvements of the software successively were introduced. The aim at the end is to deliver a calculation tool adapted to future sound insulation requirements in multi storey residential units, e.g. the accuracy of the model has to fit to the frequencies that causes annoyance. Additionally Silent Timber Build models are used in order to design some of the timber structures presented in the European Database available at www.lignum.ch. In this database a listening tool is integrated, making it easier for users to translate acoustical figures to hearing impression. Specifically, this paper comprises a description of the project and its main results but also some significant examples of calculated floor assemblies and wall assemblies. It also summarizes some main difficulties as modelling timber structures and finally recommendations for future development of the wooden industry.