Product novelty 04. October 2021

Noise, vibrations and shocks affect the quality of life and everyday comfort. According to the latest studies by the World Health Organization, noise is the second biggest health threat to people. The mobility sector in particular is one of the main sources of noise. With the lightweight structures that are increasingly used here, lower fuel consumption and CO2 emissions can be achieved, but these structures cause greater vibration amplitudes due to their greater flexibility, which results in unfavorable operating conditions, wear and tear and noise. Conventional approaches for vibration and noise reduction, such as the use of insulating material, individual dampers and acoustic resonators, can only solve these problems to a limited extent. Structures with periodically arranged resonators, on the other hand, can resolve the trade-off between lightweight construction and optimal vibroacoustic behavior. These structures are called vibroacoustic metamaterials (VAMM). The aim of the “Metavib” project is to make these VAMM usable for industrial purposes. For the first time, the Fraunhofer researchers have made it possible to address the entire value chain of VAMM. Active metamaterials in particular are of great interest. While with the passive VAMM vibration damping is achieved solely through the use of a certain material, with the active VAMM additional small actuators are built in, with which the acoustic properties of the material can be continuously adjusted. In this way, a basic module can be adapted to a variety of applications. Aging processes and external disturbances in operation can also be compensated. The added value: Metamaterials are more efficient than natural materials and can address existing problems such as susceptibility to vibration in the lightweight construction industry or the lack of compactness of noise abatement measures in the low frequency range.