AbstractAn interesting option for coastal wave attenuation can be provided by tethered floating breakwaters (see e.g. Agerton, 1976 and Seymour, 1979). This type of structure can be designed to be effective, while determining a very small impact on the environment (Dai, 2018). In principle, a regular lattice of reversed pendula (i.e. the breakwater) can be seen as an approximation to a mechanical metamaterial with interesting properties related to its periodic structure. The tethered floating breakwater we are studying has been designed as a finite lattice of submerged inverse pendula. The objective is to determine the efficiency of a regular two-dimensional lattice of spherical pendula. To isolate the one-dimensional behavior, a single array of reversed cylindrical pendula anchored to the bottom and excited by long crested waves has been tested.
Agerton, Savage and Stotz (1976): Design, analysis and field test of a dynamic floating breakwater, In: Proceedings of Coastal Engineering 1976 3, 2792-2809.
Brulè, Enoch and Guenneau (2020): Emergence of seismic metamaterials: Current state and future perspectives, Physics Letters A 384, 126034.
Dai et al. (2018): Review of recent research and developments on floating breakwaters, Ocean Engineering 158, 132-151.
Davies and Heathershaw (1984): Surface wave propagation over sinusoidally varying topography, Journal of Fluid Mechanics 144, 419-443.
De Vita et al. (2021): Attenuating surface gravity waves with mechanical metamaterials, Physics of Fluids, 33(4).
Grue (1992): Nonlinear water waves at a submerged obstacle or bottom topography, Journal of Fluid Mechanics 244, 455.
Hussein et al. (2014): Dynamics of phononic materials and structures: Historical origins, recent progress, and future outlook. Applied Mechanics Reviews, 66(4).
Lorenzo et al. (2022): METAREEF, a sustainable submerged floating metamaterial structure to attenuate surface gravity waves, Proceedings of 37th IWWWFB.
Lu, Feng and Chen (2009): Phononic crystals and acoustic metamaterials, Materials Today 12, 34-43.
Luijendijk, Hagenaars et al. (2018): The State of the World’s Beaches, Scientific Reports, 8(1), 1-11.
Ouyang, Chen and Tsai (2015): Investigation on Bragg reflection of surface water waves induced by a train of fixed floating pontoon breakwaters, International Journal of naval Architecture and Ocean Engineering 7, 951-963.
Patil and Matlack (2021): Review of exploiting nonlinearity in phononic materials to enable nonlinear wave responses, Acta Mechanica 233, 1-46.
Seymour and Hanes (1979): Performance analysis of tethered float breakwater, Journal of the Waterway, Port, Coastal and Ocean Division 105, 265-280.
Zelt and Skjelbreia (1992): Estimating incident and reflected wave fields using an arbitrary number of wave gauges, In: Proc. of the 23rd Int. Conf. on Coastal Eng. 1, 777-788.
This work is licensed under a Creative Commons Attribution 4.0 International License.
Copyright (c) 2023 Matteo Lorenzo, Paolo Pezzutto, Filippo De Lillo, Piero Ruol, Federico Bosia, Miguel Onorato