Acoustic metamaterials for structure-borne sound isolation in multi-storey timber buildings

Overview

Transmission of 20–120 Hz structure-borne sound through timber floor systems in multi-storey timber buildings does not fall within NCC requirements yet causes significant discomfort for occupants. Existing approaches to attenuation – increased mass and stiffness and viscoelastic vibration isolation – are impractical due to the very long wavelengths. Recent advancements in solid state physics have shown potential to overcome this impasse. This project is developing a system using a novel technology (metamaterials) to attenuate low frequency structure-borne sound in multi-storey timber buildings.

Key outcomes

A solution to this problem would improve the low frequency acoustic performance of multi-storey timber buildings. This has been recognised as a significant issue for over forty years. Acoustic metamaterial approaches offer real potential for the development of a practical and cost-effective solution. The key challenge is to achieve broadband attenuation with minimal additional mass. Nonlinear acoustic metamaterials, capable of inducing wide chaotic attenuation bands for low amplitude vibrations offer outstanding performance in this respect. That approach is therefore being employed in this project. The system is currently being modelled. The model will be used to undertake a parametric design study in order to identify an optimal configuration for design, construction and testing a physical prototype.

Research team

• Bernard Gibson
• Prof Tuan Ngo
• Prof Priyan Mendis
• Benoit Belleville

Research partners and collaborators

• FWPA