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Zieliński T.G., Opiela K.C., Dauchez N.♦, Boutin T.♦, Galland M.-A.♦, Attenborough K.♦, Extremely tortuous sound absorbers with labyrinthine channels in non-porous and microporous solid skeletons,
APPLIED ACOUSTICS, ISSN: 0003-682X, DOI: 10.1016/j.apacoust.2023.109816, Vol.217, pp.109816-1-13, 2024Abstract: An assembly of additively-manufactured modules to form two-dimensional networks of labyrinthine slits results in a sound absorber with extremely high tortuosity and thereby a relatively low frequency quarter wavelength resonance. Fully analytical modelling is developed for the generic design of such composite acoustic panels, allowing rapid exploration of various specific designs. In addition to labyrinthine channels in a non-porous solid skeleton, a case is also considered where the skeleton has microporosity such that its permeability is very much lower than that due to the labyrinthine channels alone. The analytical modelling is verified by numerical calculations, as well as sound absorption measurements performed on several 3D printed samples of modular composite panels. The experimental validation required overcoming the non-trivial difficulties related to additive manufacturing and testing samples of extreme tortuosity. However, due to the two-dimensionality and modularity of the proposed design, such absorbers can possibly be produced without 3D printing by assembling simple, identical modules produced separately. The experimental results fully confirmed the theoretical predictions that significant sound absorption, almost perfect at the peak, can be achieved at relatively low frequencies using very thin panels, especially those with double porosity. Keywords: Sound absorption,Extreme tortuosity,Double porosity,Acoustic composites,Additive manufacturing Affiliations:
Zieliński T.G. | - | IPPT PAN | Opiela K.C. | - | IPPT PAN | Dauchez N. | - | Sorbonne University Alliance (FR) | Boutin T. | - | Sorbonne University Alliance (FR) | Galland M.-A. | - | École Centrale de Lyon (FR) | Attenborough K. | - | The Open University (GB) |
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Zielinski T.G., Dauchez N.♦, Boutin T.♦, Leturia M.♦, Wilkinson A.♦, Chevillotte F.♦, Bécot F.-X.♦, Venegas R.♦, Taking advantage of a 3D printing imperfection in the development of sound-absorbing materials,
APPLIED ACOUSTICS, ISSN: 0003-682X, DOI: 10.1016/j.apacoust.2022.108941, Vol.197, pp.108941-1-22, 2022Abstract: At first glance, it seems that modern, inexpensive additive manufacturing (AM) technologies can be used to produce innovative, efficient acoustic materials with tailored pore morphology. However, on closer inspection, it becomes rather obvious that for now this is only possible for specific solutions, such as relatively thin, but narrow-band sound absorbers. This is mainly due to the relatively poor resolutions available in low-cost AM technologies and devices, which prevents the 3D-printing of pore networks with characteristic dimensions comparable to those found in conventional broadband sound-absorbing materials. Other drawbacks relate to a number of imperfections associated with AM technologies, including porosity or rather microporosity inherent in some of them. This paper shows how the limitations mentioned above can be alleviated by 3D-printing double-porosity structures, where the main pore network can be designed and optimised, while the properties of the intentionally microporous skeleton provide the desired permeability contrast, leading to additional broadband sound energy dissipation due to pressure diffusion. The beneficial effect of additively manufactured double porosity and the phenomena associated with it are rigorously demonstrated and validated in this work, both experimentally and through precise multi-scale modelling, on a comprehensive example that can serve as benchmark. Keywords: double porosity, additive manufacturing, sound absorption, pressure diffusion, multi-scale modelling Affiliations:
Zielinski T.G. | - | IPPT PAN | Dauchez N. | - | Sorbonne University Alliance (FR) | Boutin T. | - | Sorbonne University Alliance (FR) | Leturia M. | - | Sorbonne University Alliance (FR) | Wilkinson A. | - | Sorbonne University Alliance (FR) | Chevillotte F. | - | MATELYS – Research Lab (FR) | Bécot F.-X. | - | MATELYS – Research Lab (FR) | Venegas R. | - | MATELYS – Research Lab (FR) |
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Zieliński T.G., Opiela K.C., Pawłowski P., Dauchez N.♦, Boutin T.♦, Kennedy J.♦, Trimble D.♦, Rice H.♦, Van Damme B.♦, Hannema G.♦, Wróbel R.♦, Kim S.♦, Ghaffari Mosanenzadeh S.♦, Fang N.X.♦, Yang J.♦, Briere de La Hosseraye B.♦, Hornikx M.C.J.♦, Salze E.♦, Galland M.-A.♦, Boonen R.♦, Carvalho de Sousa A.♦, Deckers E.♦, Gaborit M.♦, Groby J.-P.♦, Reproducibility of sound-absorbing periodic porous materials using additive manufacturing technologies: round robin study,
Additive Manufacturing, ISSN: 2214-8604, DOI: 10.1016/j.addma.2020.101564, Vol.36, pp.101564-1-24, 2020Abstract: The purpose of this work is to check if additive manufacturing technologies are suitable for reproducing porous samples designed for sound absorption. The work is an inter-laboratory test, in which the production of samples and their acoustic measurements are carried out independently by different laboratories, sharing only the same geometry codes describing agreed periodic cellular designs. Different additive manufacturing technologies and equipment are used to make samples. Although most of the results obtained from measurements performed on samples with the same cellular design are very close, it is shown that some discrepancies are due to shape and surface imperfections, or microporosity, induced by the manufacturing process. The proposed periodic cellular designs can be easily reproduced and are suitable for further benchmarking of additive manufacturing techniques for rapid prototyping of acoustic materials and metamaterials. Keywords: porous materials, designed periodicity, additive manufacturing, sound absorption Affiliations:
Zieliński T.G. | - | IPPT PAN | Opiela K.C. | - | IPPT PAN | Pawłowski P. | - | IPPT PAN | Dauchez N. | - | Sorbonne University Alliance (FR) | Boutin T. | - | Sorbonne University Alliance (FR) | Kennedy J. | - | Trinity College (IE) | Trimble D. | - | Trinity College (IE) | Rice H. | - | Trinity College (IE) | Van Damme B. | - | other affiliation | Hannema G. | - | other affiliation | Wróbel R. | - | other affiliation | Kim S. | - | other affiliation | Ghaffari Mosanenzadeh S. | - | other affiliation | Fang N.X. | - | other affiliation | Yang J. | - | Clemson University (US) | Briere de La Hosseraye B. | - | other affiliation | Hornikx M.C.J. | - | other affiliation | Salze E. | - | other affiliation | Galland M.-A. | - | École Centrale de Lyon (FR) | Boonen R. | - | other affiliation | Carvalho de Sousa A. | - | other affiliation | Deckers E. | - | Katholieke Universiteit Leuven (BE) | Gaborit M. | - | other affiliation | Groby J.-P. | - | other affiliation |
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