Time-domain broadband acoustic carpet type invisible garment and manufacturing method

Abstract

The invention belongs to the technical field of acoustics, and particularly relates to a time-domain broadband acoustic carpet type invisible garment and a manufacturing method. A broadband sound pressure local reflection theorem and a parameter optimization method are combined, a multilayer air square hole stacked structure is used as a metasurface basic structure unit, and a time domain broadband metasurface structure is designed through reverse optimization by the aid of a genetic algorithm. According to the designed time domain broadband metasurface structure, invisibility of sound waves within the frequency range of 2,000-5,500 Hz can be realized, the relative bandwidth is 93% or above, the invisible performance of the time domain broadband is displayed under multi-frequency pulse incidence, the limitation of narrow bandwidth of a traditional passive metasurface and the defect of adjustable metasurface time domain broadband are broken through, and a key research basis is providedfor the broadband acoustic metasurface structure design and the practical application of a broadband acoustic device.

Description

technical field [0001] The invention belongs to the technical field of acoustics, and in particular relates to a time-domain broadband acoustic carpet-type invisibility cloak and a manufacturing method thereof. Background technique [0002] In recent years, acoustic metamaterials have demonstrated a unique ability to manipulate sound waves. As a two-dimensional planarization of acoustic metamaterials, the thickness of the acoustic metasurface is controlled within the sub-wavelength scale, and the phase and amplitude of the acoustic wave can be adjusted arbitrarily only through the gradient arrangement of a layer of microstructural units. To achieve the purpose of controlling large wavelengths with a small size, breaking the limitation of larger size of volumetric acoustic metamaterials. [0003] The regulation of acoustic metasurfaces on acoustic waves is usually based on the generalized Snell's theorem, by setting the phase distribution of gradients on the metasurface to c...

AI Technical Summary

Problems solved by technology

However, since the phase that the cloak needs to adjust changes with the incident frequency, the cloak made of metasurface can only work in a narrow target frequency range. The bandwidth is only about 7% to 36%

In addition, although there is an adjustable or reconfigurable way to broaden the operating frequency range of the metasurface cloak, but because the metasurface requires different geometric configurations at different frequencies, this cloak Under the incident of a multi-frequency pulse sound wave, it is still impossible to achieve time-domain broadband invisibility, but the time-domain broadband invisibility cloak can better hide objects from being discovered by the outside world

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