A Design Method for Thin Shell Acoustic Superstructures with Arbitrary Surface Shape

A design method and technology of thin shell structure, applied in the direction of sound-producing equipment, instruments, etc., can solve problems such as lack of design methods, and achieve the effect of reducing environmental noise pollution

CN110223666BActive Publication Date: 2021-03-23XI AN JIAOTONG UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2021-03-23

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Abstract

The invention discloses a design method of a thin-shell-type acoustic superstructure in any curved surface shape. The design method is used for design of a thin-shell-type low-and-medium-frequency broadband sound insulation structure, design of a curved surface shell-shaped ultra-thin light sound absorption structure, design of an ultra-thin carpet-type acoustic invisibility cloak fitting the complex curved surface shape, and the like. According to the thin-shell-type sound insulation structure designed through the method, after the curvature radius is decreased to a certain range, a sound insulation index curve can break through the cut-off frequency limit between a stiffness control area and a damping control area, the sound insulation trough at the cut-off frequency is eliminated, and excellent low-frequency broadband sound insulation performance is achieved. By properly selecting the separation distance between double-layer shells, a double-layer shell structure can achieve bianisotropic perfect sound absorption; and in order to adjust phase compensation of the designed complex curved surface shape structure and achieve the function of arbitrary adjusting and control of a wavefront phase, the equiphase design method is adopted, and the curved surface carpet-type acoustic invisibility cloak completely fitting the complex structure surface morphology can be designed.
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Description

technical field

[0001] The invention belongs to the technical field of acoustic superstructures, and in particular relates to a design method for a thin-shell acoustic superstructure with an arbitrary curved surface shape. Background technique

[0002] Acoustic superstructure is an artificial composite structure with subwavelength dimensions. Through microstructure design, acoustic bandgap, negative equivalent mass density, negative bulk modulus, double negative equivalent parameters, negative refractive index, and negative shear can be realized. Modulus, total reflection, anomalous reflection / refraction, perfect sound absorption, sound focusing, self-collimation, anomalous Doppler effect, non-reciprocal sound transmission and many other strange physical phenomena. Therefore, it shows promising and extensive application prospects in vibration and noise suppression, acoustic imaging, acoustic energy focusing, metalens, waveguide and stealth. According to the working principl...

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Embodiment Construction

[0048] The present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments.

[0049] (1) Broadband ultra-strong sound insulation thin shell structure design

[0050] Thin-shell structures are the most commonly used thin-walled structures in engineering. Commonly used thin-shell structures include rotating shells and cylindrical shells, or many structures are complex curved shell structures that are compounded or evolved from these two types of structures, such as attached figure 1 shown. Among the two commonly used thin shell structures, cylindrical shells are more widely used than rotary shells. However, considering that the cylindrical shell structure is not convenient for acoustic performance measurement, the present invention first designs a rotating shell structure for experimental verification. For comparison, two sets of structures (S0 and S1) of thin plate and hemispherical rotating shell were designed respec...