Thin broadband sound-absorbing structure of composite multi-layer mechanical impedance plates

Abstract

The invention provides a thin broadband sound-absorbing structure. The structure comprises a sound-absorbing material, a support and at least two layers of mechanical impedance plates, wherein the sound-absorbing material is installed on the inner side of one end of the support, a supporting plate is arranged on the inner wall of the other end of the support, each of the mechanical impedance plates consists of a back plate and sticky elastic rings at two ends of the back plate, adjacent back plates are not in contact, sticky elastic rings are stuck to the supporting plate through an adhesive, the sticky elastic rings, the support inner wall and the back plates are attached tightly, a hollow is formed among the sound-absorbing material and the mechanical impedance plates, and the back plate on the outermost side is recessed towards the support end face by certain distance. Mechanical impedance is coupled to a traditional sound-absorbing material and a cavity resonance absorption mechanism, a novel thin broadband sound-absorbing mechanism is formed, the structure thickness is not increased basically based on the acoustic performance, the middle / high-frequency sound absorption performance is good, the low-frequency sound absorption effect is improved greatly and the sound-absorbing structure of which the thickness is thin and the sound-absorbing frequency band is wide is produced.

Description

technical field [0001] The invention relates to a sound-absorbing device, a novel sound-absorbing structure combining mechanical impedance and traditional sound-absorbing materials, and belongs to the technical field of environmental noise control. Background technique [0002] Among the sound-absorbing materials of traditional porous materials and micro-perforated plate sound-absorbing structures, there are sound-absorbing materials of glass wool, slag wool, rock wool, foam plastic, asbestos wool, felt, and soft fiberboard. Generally, sound-absorbing materials (structures) have good medium and high sound-absorbing performance, but poor low-frequency sound-absorbing performance; the micro-perforated plate structure uses the resonance of the cavity, and in the case of limited space, it also has poor low-frequency sound-absorbing performance; The thin-film sound-absorbing structure and the thin-plate sound-absorbing structure only absorb sound near the resonance frequency, and...

AI Technical Summary

Problems solved by technology

Generally, sound-absorbing materials (structures) have good medium and high sound-absorbing performance, but poor low-frequency sound-absorbing performance; the micro-perforated plate structure uses cavity resonance, and in the case of limited space, also has poor low-frequency sound-absorbing performance; Film sound-absorbing structure and thin-plate sound-absorbing structure only absorb sound near the resonance frequency, and the sound-absorbing frequency band is narrow

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