Testing And Analysis Of The Sound Absorption Characteristics Of Perforated Plates

In the field of acoustics,using the sound absorption to control noise is one of the important measures to improve environment.There are two typical ways:one is the sound-absorbing materials,the other is the sound-absorbing structures.Since 19th century,the studies on theory and application of perforated plates have attracted much interests among researchers,that is because it has a lot of advantages like rich decoration?enough strength?manageable acoustic performance and so on.Hence,it has been used widely.In this paper,taking the galvanized perforated plate as an example,using reverberation chamber to test the sound-absorption characteristics of galvanized perforated plates and analyze the different parameters effect on its sound-absorption characteristics;then using impedance tube to test and analyze it;According to the acoustical absorption coefficient,analyzing this two methods' effects on its sound-absorption characteristics.Through studying the sound-absorption characteristics of galvanized perforated plates found that it has low acoustical absorption coefficient and the absorption band is narrow.Moreover,by analyzing different parameters effect on its sound-absorption characteristics,can draw the following conclusions:(1)fixing aperture?perforative rate?thickness and changing arrangement,the absorption peak of square arrangement(near the resonant frequency)is the same with triangle,in other words,arrangement has little effects on its sound-absorption performance;(2)fixing the arrangement?aperture?thickness and changing perforative rate,with the increasing of perforative rate,the absorption peak(near the resonant frequency)moves to higher frequency;(3)fixing the arrangement?perforative rate?thickness and changing aperture,with the increasing of aperture,the absorption peak(near the resonant frequency)moves to lower frequency;(4)fixing the arrangement?aperture?perforative rate and changing thickness,with the increasing of thickness,the absorption peak(near the resonant frequency)moves to lower frequency.The result has some reference value to researching the sound-absorption characteristics of perforated plates.According to the data,the program of the sound-absorption performance of galvanized perforated plate test data management system is written.It divides into three big modules:the user login information management?the galvanized perforated plate absorption coefficient management and the galvanized perforated plate absorption coefficient comparison management,This not only can provide a convenient test information query,also can improve the speed of data processing and prevent the loss of data.