HUESPE Alfredo Edmundo
Computational material design for acoustic cloaking
MÉNDEZ, C.; PODESTÁ, J. M.; LLOBERAS-VALLS, O.; TORO, S.; HUESPE, A. E.; OLIVER, J.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
JOHN WILEY & SONS LTD
Año: 2017 vol. 112 p. 1353 - 1380
A topology optimization technique based on the topological derivative andthe level set function is utilized to design/synthesize the micro-structure of apentamode material for an acoustic cloaking device.The technique provides a micro-structure consisting of a honeycomb latticecomposed of needle-like and joint members. The resulting metamaterial showsa highly anisotropic elastic response with effective properties displaying a ratiobetween bulk and shear moduli of almost 3 orders of magnitude. Furthermore,in accordance with previous works in the literature, it can be asserted thatthis kind of micro-structure can be realistically fabricated.The adoption of a topology optimization technique as a tool for the inversedesign of metamaterials with applications to acoustic cloaking problems is onecontribution of this paper. However, the most important achievement refersto the analysis and discussion revealing the key role of the external shape ofthe prescribed domain where the optimization problem is posed.The efficiency of the designed micro-structure is measured by comparingthe scattering wave fields generated by acoustic plane waves impinging onbare and cloaked bodies.