Double-acoustic-impedance periodic micropunch ultra-wide-band sound absorption structure

Abstract

The invention relates to a double-acoustic-impedance micropunch sound absorption structure of periodic change. A micropunch panel, a unit separator plate, a unit base plate and left, right, front andback end surfaces are connected to form an enclosed cavity in periodic arrangement, a cavity change periodically between two depths, and the higher depth is 1.5-4.5 times of the lower depth. Micropores which occupy 0.5%-4% the area of the panel are distributed in the micropunch panel, the aperture of the micropores is 0.3-1.2mm, and the unit width does not exceed 0.2m. During use, it is only required to install the structure in a place which needs sound absorption by fix the structure on the wall surface. The structure is simple, easy to process, thin, light, and excellent in a sound absorption performance, the sound-absorption frequency band width can reach three frequency multiplication ranges when the sound absorption coefficient is greater than 0.8 within 2.5KHz, the peak value approaches 1.0, the sound absorption performance is smooth, the applicability is wide, the structure is easy to clean and resistant to high temperature, has a high weather resistance, can be reutilized completely, includes no filled fibrous materials, avoids secondary pollution completely, and has high environment protection performance.

Description

technical field [0001] The invention belongs to the technical field of acoustics, in particular to a double-acoustic impedance periodic change micro-perforated ultra-wideband sound-absorbing structure for middle and low frequency noise. Background technique [0002] The problem of noise pollution is becoming more and more serious with the development of urban economy and the growth of population. The complaints caused by the impact of noise pollution on people account for more than 50% of all kinds of environmental complaints in economically developed cities. With the advancement of urbanization, the increasing social activities and the use of equipment make people's living environment have obvious low-frequency characteristics, which often causes people to feel annoyed subjectively when the sound pressure level of environmental noise has not reached the standard limit. Low-frequency noise can significantly interfere with people's thinking ability and affect people's auditor...

AI Technical Summary

Problems solved by technology

[0005] However, for ordinary resonant sound-absorbing structures with a single cavity, in order to have good sound-absorbing performance at low frequencies, the depth of the cavity must be greatly increased, and the volume is often large

In addition, the common resonant sound-absorbing structure with a single cavity has a narrow sound-absorbing frequency band. For a micro-perforated plate with a pore size of 1 mm, the half-sound-absorbing bandwidth (sound absorption coefficient ≥ 0.5) is usually less than 2 octaves

The lower the sound-absorbing frequency requirement, the greater the thickness of the sound-absorbing structure. In situations where the space is generally limited, ordinary resonant sound-absorbing structures cannot well meet the actual needs of noise control.

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