Spider web-inspired acoustic metamaterials for sound manipulation, by Anastasiia Krushynska (University of Turin) [Jan. 25, 2017]
DENORMS Action’s Workshop “Modelling of high performance acoustic structures Porous media, metamaterials and sonic crystals”, Rome, 24-25th January 2017
Session on New trends in vibroacoustics (i.e. elastic metamaterials and metasurfaces)
Speaker: Anastasiia Krushynska (University of Turin)
Outstanding mechanical performance of spider webs is attributed not only to remarkable properties of constituent silk materials, but also to an optimized architecture adapted to various spider functionalities. Previous studies have revealed the peculiar response of a spider-web under dynamic loading conditions, which appears to be responsible for the mechanisms of prey recognition and capture. However, a spider-web architecture is yet to be considered for the design of metamaterials. In this talk, we propose two designs for acoustic metamaterials based on the Nephila spider orb web architecture. The first geometry is constructed using the periodic repetition of spider-web-inspired unit cells in a square lattice and is found to efficiently attenuate elastic waves in the sonic frequency range due to locally resonance phenomena. The second geometry consists of a periodic array of spider-web architectures with each of them acting as a circularly polarized metamaterial. The capability of the resulting structure to inhibit elastic wave propagation in subsonic frequency ranges is assessed, also including in the case of coupling between acoustic and elastic fields. Parametric studies are performed to derive optimal configurations and constituent mechanical properties. The results show promise for the design of innovative lightweight structures for tunable sound attenuation as well as for vibration and impact mitigation or the protection of large scale infrastructure such as suspended bridges.