COMPUTATIONAL MATERIAL DESIGN FOR ACOUSTIC CLOAKING

CARLOS MÉNDEZ; ALFREDO HUESPE; JUAN MANUEL PODESTÁ; XAVIER OLIVER

Crete Island

Congreso; European Congress on Computational Methods in Applied Sciences and Engineering; 2016

Institute of Structural Analysis and Antiseismic Research

Inspired by its electromagnetic counterpart, acoustic cloaking has been an active field of research in recent years and now the theoretical background of what is called transformation acoustic (TA) is well established. The ideal cloaking predicted by TA is for all frequencies and all directions; however, the feasibility of real devices is still under development because of the peculiar properties that are required for the constituent materials. With the help of topology optimization, in this work we show how these special (meta) materials can be designed. Specifically, we use topological derivative for the optimization and we consider quadrangular and hexagonal RVEs (representative volume elements). We also make the simulation of the acoustic wave propagation through the obstacle and we compare the effectiveness of the cloaking using the designed materials with theoretical predictions by the calculation of the scattering cross section. In addition, the influence of several parameters, like different sizes of the cloak or different materials for the obstacles, is analyzed.