Low-frequency broadband composite micro-perforated panel sound absorption structure

Abstract

The invention provides a low-frequency broadband composite micro-perforated plate sound absorption structure which comprises a perforated plate, a sound absorption back cavity with an opening in the upper end and a plurality of inclined back plates, submillimeter holes are formed in the perforated plate, the perforated plate covers the opening in the upper end of the sound absorption back cavity, and the inclined back plates are arranged in the sound absorption back cavity. All the inclined back plates are sequentially and fixedly connected end to end from top to bottom to form a snakelike fold line structure, the included angles between all the inclined back plates and the horizontal plane are the same, one ends of the inclined back plates are alternately fixed to the front frame plate and the rear frame plate, and slits are formed between the other ends of the inclined back plates and the left frame plate and the right frame plate. And all the inclined back plates divide the sound absorption back cavity into bent channels. The inclined back plate structure is added in the micro-perforated plate sound absorber, so that the frequency of the sound absorption peak of the micro-perforated plate sound absorber is reduced, and the sound absorption coefficient at the peak frequency is improved; an additional absorption peak is introduced on an original sound absorption curve; and after the porous material is added into the structure, the sound absorption frequency band of the perforated plate is effectively widened.

Description

technical field [0001] The invention belongs to the technical field of sound-absorbing structures, and in particular relates to a low-frequency broadband composite micro-perforated plate sound-absorbing structure. Background technique [0002] The micro-perforated plate is formed by punching submillimeter-level small holes on the surface of the plate with a certain thickness, and the micro-perforated plate structure sound absorber (MPA) is generally composed of a micro-perforated plate and a cavity with a certain depth of plate thickness. When the sound wave is incident on the small hole, the inner wall of the small hole will frictionally absorb the sound wave and absorb the sound wave to achieve the purpose of sound absorption. The existing micro-perforated plate sound absorber has only one resonant absorption peak, and the effective absorption bandwidth (sound absorption coefficient greater than 50%) is mainly concentrated in the intermediate frequency. The acoustic bandw...

AI Technical Summary

Problems solved by technology

The existing micro-perforated plate sound absorber has only one resonant absorption peak, and the effective absorption bandwidth (sound absorption coefficient greater than 50%) is mainly concentrated in the intermediate frequency. The acoustic bandwidth is narrow, and effective sound absorption cannot be performed above high frequencies. Therefore, it is necessary to design a low-frequency broadband composite micro-perforated plate sound-absorbing structure to solve the above problems.

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