| 1. | Niedzielczyk M., Galland M.-A.♦, Zieliński T.G., An acoustic material with tortuous slits filled with fibres, ISMA2024 / USD2024, 31st International Conference on Noise and Vibration Engineering / International Conference on
Uncertainty in Structural Dynamics, 2024-09-09/09-11, Leuven (BE), pp.323-336, 2024 Abstract:The work presents a comprehensive approach to the design and modelling of acoustic materials based on labyrinth structures filled with fibres. It has recently been shown that exceptionally favourable acoustic properties can be obtained in labyrinthine materials due to their extreme tortuosity. Such materials, typically produced by methods such as 3D printing, exhibit high sound absorption values at lower frequencies. The next step in the development of this type of acoustic treatment (explored here) involves introducing fibres into labyrinthine channels. Such acoustic composite designs can have a beneficial effect of shifting the absorption peak to even lower frequencies and also widening its efficiency range. Two samples of slotted labyrinth materials, designed using analytical acoustic modelling, were 3D printed, and their slits were filled with selected fibrous materials, such as biofibres, cotton wool, acrylic yarn, etc. They were tested in an impedance tube to confirm the predicted improvement, but also to show a dramatic change in sound absorption. Affiliations:| Niedzielczyk M. | - | IPPT PAN | | Galland M.-A. | - | École Centrale de Lyon (FR) | | Zieliński T.G. | - | IPPT PAN |
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