Optimization study of acoustic characteristics for assembled curled structure

Abstract In this paper, a simple curled G-type structure is used as the basic unit, which is coded according to its different opening directions, and a composite structure model with special acoustic functions is constructed by different types of assembly methods. The curled G-structure as the basic unit has the characteristics of a Helmholtz resonator, which can resonate at a specific frequency and effectively attenuate the acoustic energy. In the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>2</mml:mn> <mml:mo>×</mml:mo> <mml:mn>2</mml:mn> </mml:math> matrix assembly, there exists an optimal model with an ultra-wide forbidden bandwidth of 510 – 2120 Hz, which also has a high degree of symmetry and the bandgap characteristics of phononic crystals. In the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>1</mml:mn> <mml:mo>×</mml:mo> <mml:mi mathvariant="normal">N</mml:mi> </mml:math> matrix assembly, the optimization is performed by genetic algorithm, and N is taken as 4 to achieve tunable acoustic focusing. The simplicity of the curled G-type structure and the simple assembly method make the resulting composite structure have a wide range of potential applications in areas such as noise reduction and imaging.