Broadband micro-perforated board sound absorber, absorber performance prediction method and absorber structure design method

Abstract

The invention discloses a broadband micro-perforated board sound absorber, a sound absorber performance prediction method and a sound absorber structure design method. The sound absorber comprises a surface micro-perforated board and a back chamber with unequal periodicity depth, and the back chamber is used for expanding sound absorption bandwidth of the sound absorber. The performance prediction method is used for predicting a sound absorption coefficient frequency spectrum of the sound absorber, through finite element simulation and experiment measurement verification, the performance prediction method is accurate and reliable; the structure design method used for effectively realizing the broadband micro-perforated board sound absorber comprises steps that (1), a depth matrix of the periodic back chamber is designed on the basis of the secondary residual sequence combination arrangement theory; and (2), evaluation is realized on the basis of the performance prediction method, combination of parameters of the sound absorber are sequentially determined, including total sound absorber width of the periodic back chamber, depth of each sub back chamber, board thickness of the micro-perforated board, aperture and perforated percentage. Through the sound absorber performance prediction method and the sound absorber structure design method, the micro-perforated board sound absorber having the broadband sound absorption performance can be accurately, reliably and simply designed.

Description

technical field [0001] The invention relates to the field of environmental noise control and sound absorption of indoor acoustic decoration, in particular to a wide-band high-performance micro-perforated plate sound-absorbing body and its performance prediction and structural design methods. Background technique [0002] At present, a typical micro-perforated panel sound absorber consists of a single-layer uniformly perforated micro-perforated panel and its corresponding single panel rear cavity. Different from the sound-absorbing materials of traditional porous materials and fiber materials, it has a simple structure, and the structure can be made of various materials, such as metal, plastic, wood and even glass. The advantages include no debris after long-term use, the surface can resist impact, moisture and water, and can adapt to high-speed airflow, etc. It is an environmentally friendly new sound-absorbing material. However, a prominent problem in the application of th...

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Problems solved by technology

[0004] CN1311380A discloses an ultra-wideband micro-perforated plate sound absorber and its manufacturing method and equipment, including a micro-perforated plate and a box-shaped member with a rear cavity depth D integrated with the micro-perforated plate, and the box-shaped member is provided with a support The baffle grid, by reducing the perforated plate constant K of the micro-perforated plate, can achieve the purpose of increasing the sound-absorbing frequency band for practical applications, and achieve high-frequency sound-absorbing performance, but the depth of the back cavity of the box-shaped member is constant, and it is impossible to form local Resonance effect; CN102968985A discloses a thin broadband sound-absorbing structure of a composite multilayer mechanical impedance plate, including sound-absorbing materials and supports, and at least two layers of mechanical impedance plates, and the sound-absorbing materials can be traditional porous materials and micro-perforated plate absorbers The acoustic structure is used to absorb high-frequency noise, while the low-frequency noise is dissipated by the vibration of the mechanical impedance plate; CN102646414A discloses a combined sound-absorbing structure based on micro-perforation and intracavity resonance system, including micro-perforation plate, back cavity and the intracavity resonance system, aiming to adjust the parameters of the intracavity resonance system (plate mass, force resistance, spring stiffness coefficient), parameters of the micro-perforated plate (aperture diameter, plate thickness, perforation rate) and the depth of the back cavity to achieve a relatively Broadband sound absorption; CN102332259A discloses an adaptive micro-perforated plate sound absorber and its micropore real-time adjustment method, including a piezoelectric film micro-perforated plate, an active control circuit, an adaptive controller and a noise detector. The incident noise adjusts the size of the micropores on the piezoelectric film micro-perforated plate in real time to effectively expand the sound-absorbing frequency band of the resonant sound-absorbing structure of the micro-perforated plate

[0005] The existing technology and design of micro-perforated plate sound absorbers, there is no report on broadband micro-perforated plate sound absorbers based on “parallel” arrangement of different depth back cavity design

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