Topological Optimization of Two-Dimensional Binary Solid Phononic Crystals Based on the FDTD Method and Multiple-Elitist Genetic Algorithm
Xiao-Xing Su (School of Electronic and Information Engineering, Beijing Jiaotong University), Hao-Wen Dong (), yue-Sheng Wang (Institute of Engineering Mechanics, Beijing Jiaotong University), Chuanzeng Zhang (Department of Civil Engineering, University of Siegen)
Mechanics and Dynamics of Periodic Structures
Wed 3:10 - 4:30
Salomon 101
The topological optimization for maximizing the absolute band gaps of the two-dimensional (2D) bi-component solid phononic crystals (PnCs) is studied. The finite difference time-domain (FDTD) method and the multiple-elitist genetic algorithm (MEGA), are adopted as the forward calculation method and the inverse search scheme, respectively. The square-latticed Au/Epoxy and Pb/Epoxy PnC systems that are with different material contrast are considered. The optimizations are performed for the symmetric structure that is invariant under the mirror reflection with respect to both the two axes and under a 90° rotation around the origin, and the asymmetric structure with an arbitrary material distribution in the unit-cell as well. The numerical results show that the combination of the FDTD method and the MEGA can be effectively used to perform the topological optimization of 2D PnCs. Moreover, the results also show that material contrast has significant effects on the optimal structures. For the Au/Epoxy and Pb/Epoxy systems, the simple- and compound-latticed “hard in soft” optimal structures are obtained, respectively. By breaking the structural symmetry, an approximately 20% increase of the relative band gap width (RBGW) of the optimal structure can be achieved for the Pb/Epoxy system. For the Au/Epoxy system that is with significantly higher material contrast, however, no evident increase of the RBGW can be brought about by the symmetry breaking.