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

TL;DR

This study explores how reducing symmetry in the topology optimization of 2D porous phononic crystals can lead to novel structures and enhanced design flexibility, especially for chiral metamaterials.

Contribution

It demonstrates the impact of symmetry reduction on optimization outcomes and introduces a method to discover new PnC structures with potential applications in metamaterials.

Findings

Symmetry reduction influences optimized structures significantly.

Topology optimization with symmetry reduction uncovers new structures.

Rotationally symmetrical structures enable design of chiral metamaterials.

Abstract

In this paper we present a comprehensive study on the multi-objective optimization of two-dimensional porous phononic crystals (PnCs) in both square and triangular lattices with the reduced topology symmetry of the unit-cell. The fast non-dominated sorting-based genetic algorithm II is used to perform the optimization, and the Pareto-optimal solutions are obtained. The results demonstrate that the symmetry reduction significantly influences the optimized structures. The physical mechanism of the optimized structures is analyzed. Topology optimization combined with the symmetry reduction can discover new structures and offer new degrees of freedom to design PnC-based devices. Especially, the rotationally symmetrical structures presented here can be utilized to explore and design new chiral metamaterials.