On multilayered system dynamics and waves in anisotropic poroelastic media
2016 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]
The mechanical and acoustic anisotropy of media is a governing factor in the behaviour of multilayered systems including such media. The understanding of the mechanisms conditioning the dynamic behaviour of multilayered systems is of paramount importance. In particular, the intrinsic anisotropy of poroelastic media presents a potential for the optimal design of systems for multifunctional performances. Indeed, these multilayered systems are bound by stiffness, thermal and acoustic performance constraints in simultaneously. A plane wave method is presented to study the influence of material orientation in the dynamic behaviour of multilayered systems composed of anisotropic poroelastic media. The method is applied to a system composed of an anisotropic open-celled melamine foam core in between two metal sheets. This particular multilayered configuration allows to shed light on phenomena intrinsic to layers composed of anisotropic poroelastic materials, such as the frequency shift of the fundamental resonance of the panel, or the compression-shear coupling effects taking place in the poroelastic core layers. The latter phenomena is of particular importance, as it is evidenced on the unconventional polarisation of waves in anisotropic poroelastic media. Finally, the method is adapted to the optimisation of multilayered systems for acoustic performance. the design variables are consequently the core material orientations with respect to the global coordinate system. The solutions to the optimisation problem are analysed in terms of dynamic behaviour, thus allowing to correlate acoustic performance of the overall structure, and the response of each individual layer.
Ort, förlag, år, upplaga, sidor
Stockholm: KTH Royal Institute of Technology, 2016. , s. 57
Serie
TRITA-AVE, ISSN 1651-7660 ; 2016:77
Nyckelord [en]
poroelastic media, anisotropy, plane waves, multilayered systems, dynamics, acoustics, optimisation
Nyckelord [fr]
matériaux poro-visco-élastique, anisotropie, ondes planes, panneaux multicouches, dynamique, acoustique, optimisation
Nyckelord [sv]
Poroelastiska material, anisotropi, planvågor, flerskiktssystem, dynamik, akustik, optimering
Nationell ämneskategori
Farkostteknik
Forskningsämne
Farkostteknik
Identifikatorer
URN: urn:nbn:se:kth:diva-195801ISBN: 978-91-7729-172-5 (tryckt)OAI: oai:DiVA.org:kth-195801DiVA, id: diva2:1045470
Disputation
2016-12-06, F3, Lindstedtsvägen 26, Stockholm, 10:00 (Engelska)
Opponent
Handledare
Anmärkning
QC 20161110
2016-11-102016-11-092022-06-27Bibliografiskt granskad
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