Sakamoto Shuichi, Iizuka Ryo, Nozawa Takumi
Department of Engineering, Niigata University, Ikarashi 2-no-cho 8050, Nishi-ku, Niigata City 950-2181, Japan.
Graduate School of Science and Technology, Niigata University, Ikarashi 2-no-cho 8050, Nishi-ku, Niigata City 950-2181, Japan.
Materials (Basel). 2022 May 27;15(11):3840. doi: 10.3390/ma15113840.
The purpose of this study was to improve the accuracy of the theoretical analysis of sound absorption mechanisms when a back air space is used in nonwoven fabrics. In the case of a nonwoven sheet with a back air space, it can be shown that there is a difference between the experimental results and theoretical analysis results obtained using the Miki model when the area of the nonwoven sheet is large. Therefore, in this study, the accuracy of the theoretical values was improved using the plate vibration model in conjunction with the Miki model. The experimental results showed that when the vibration of the nonwoven sheet was suppressed, the sound absorption coefficient was higher than that of the vibration-prone nonwoven sheet alone. The sound absorption coefficient at the peak frequency was increased by >0.2, especially for 3501BD. Using the support frame, the sound absorption coefficient at the peak frequencies of 3A01A and 3701B was increased to 0.99. In the theoretical analysis of a large-area, vibration-prone nonwoven fabric, in which the vibration of the nonwoven fabric was taken into account, the theoretical values were in agreement with the experimental values, and the accuracy of the theoretical values was improved. Comparing the theoretical values for nonwoven fabrics without high ventilation resistance, the sound absorption coefficient was greater when vibration was not considered. Therefore, it was suggested that the vibration of the nonwoven fabric hinders sound absorption.
本研究的目的是提高在非织造织物中使用背衬空气层时吸声机制理论分析的准确性。对于带有背衬空气层的非织造片材，当非织造片材面积较大时，可以发现使用三木模型得到的实验结果与理论分析结果之间存在差异。因此，在本研究中，结合三木模型使用板振动模型提高了理论值的准确性。实验结果表明，当非织造片材的振动受到抑制时，吸声系数高于单独的易振动非织造片材。峰值频率处的吸声系数增加了>0.2，特别是对于3501BD。使用支撑框架，3A01A和3701B的峰值频率处的吸声系数提高到了0.99。在考虑非织造织物振动的大面积、易振动非织造织物的理论分析中，理论值与实验值一致，理论值的准确性得到了提高。比较无高透气阻力的非织造织物的理论值，不考虑振动时吸声系数更大。因此，有人认为非织造织物的振动会阻碍吸声。
