Genetic algorithm optimization of phononic bandgap structures

Abstract

This paper describes the use of genetic algorithms (GAs) for the optimal design of phononic bandgaps in periodic elastic two-phase media. In particular, we link a GA with a computational finite element method for solving the acoustic wave equation, and find optimal designs for both metal-matrix composite systems consisting of Ti/SiC, and H 2 O-filled porous ceramic media, by maximizing the relative acoustic bandgap for these media. The term acoustic here implies that, for simplicity, only dilatational wave propagation is considered, although this is not an essential limitation of the method. The inclusion material is found to have a lower longitudinal modulus (and lower wave speed) than the surrounding matrix material, a result consistent with observations that stronger scattering is observed if the inclusion material has a lower wave velocity than the matrix material.

Optimization and experimental validation of stiff porous phononic plates for widest complete bandgap of mixed fundamental guided wave modes

“…[10][11][12][13]) some of which addressed porous topologies [14,15]. Two other works reported optimized porous topologies for maximized RBW of asymmetric guided wave modes through genetic algorithm (GA) [16] and gradient based [17] approaches.…”

Reducing symmetry in topology optimization of two-dimensional porous phononic crystals

“…Promising applications of PnCs include sound insulation, 3 sound barrier, 4 damping, 5,6 acoustic resonators, 7,8 elastic/acoustic waveguides, 9 filters, 10 frequency sensing, 11,12 acoustic mirrors, 13 switches, 14 lenses, 15 energy harvesting, 16 negative refraction, 17,18 self-collimation, 19,20 acoustic mirages, 14 rectification, 21 acoustic diodes, 22,23 and thermal conductance. 24,25 In recent years, some researchers have been conducted and focused on topology optimization of photonic crystals (PtCs), 26,27 PnCs [28][29][30][31][32][33] and phoxonic crystals (PxCs). 34 Recent studies have shown that the topology optimization can greatly enhance the performance of PnCs, not only for bulk waves, [28][29][30][31][32][33][34] but also for surface waves 35 and plate waves.…”

“…24,25 In recent years, some researchers have been conducted and focused on topology optimization of photonic crystals (PtCs), 26,27 PnCs [28][29][30][31][32][33] and phoxonic crystals (PxCs). 34 Recent studies have shown that the topology optimization can greatly enhance the performance of PnCs, not only for bulk waves, [28][29][30][31][32][33][34] but also for surface waves 35 and plate waves. 36 However, because of the high computational effort and the complex optimization procedure, most topology optimizations of bandgap maximization assumed that the unit-cell has a primary high-symmetry.…”

“…Some researchers have obtained interesting optimized topologies based on the asymmetric assumption. 29,32,42 Preble et al 42 found that a PtC with low symmetry can open a large TE bandgap. Gazonas et al 29 performed optimization with asymmetric assumption and obtained the symmetrical PnCs in the coarse grids.…”

“…29,32,42 Preble et al 42 found that a PtC with low symmetry can open a large TE bandgap. Gazonas et al 29 performed optimization with asymmetric assumption and obtained the symmetrical PnCs in the coarse grids. Dong et al 32 designed the asymmetric solid-solid PnCs with ultra-large bandgap widths by topology optimization.…”