Development on Light and Thin Broadband Sound Absorption Structure Based on Unequal-Cross-Section Microperforated Plate Series Connection

The sound absorption structure of a microperforated plate has many advantages and has great potential in the field of noise control. In order to solve the problem of broadband sound absorption of microperforated plates, a series acoustic structure of microperforated plates of unequal cross-section was designed based on the traditional microperforated plate series acoustic structure. Compared with the traditional series structure, the sudden change of cross-section increases the sound energy dissipation and greatly improves the sound absorption performance. Through the analysis of its parameters, when the overall thickness of the structure is 20 mm, its sound absorption coefficient is above 0.5 in the frequency range of 1000-3450 Hz; there are three formants, and the sound absorption coefficients corresponding to the three formants reach 1. This study provides new ideas and methods for the design of broadband acoustic structures.