空心砖墙隔声有限元数值模拟分析

Finite Element Numerical Simulation Analysis of Sound Insulation of Hollow Brick Wall

为探究空心砖砌块内部孔洞数量及孔洞排布方式对隔声效果的影响,利用有限元方法分析两种常见厚度(115mm和190mm)空心砖墙的隔声效果,对比不同长度及宽度方向开孔数量对隔声量的影响,并通过模态分析对隔声低谷进行解释,旨在为空心砖砌块墙隔声设计提供参考。结果表明:在所设孔洞形式与尺寸下,190mm厚空心砌块墙的计权隔声量比115mm厚的高6d B;同尺寸的空心砖墙隔声量比实心砖墙低6~7d B;空心砖墙隔声低谷出现的位置取决于特征频率下的振型及位移幅值大小;增加空心砌块长度或宽度方向的开孔数可以有效提高隔声低谷处的隔声量,也可提高计权隔声量,将长度方向开孔数从2孔增加到4孔,计权隔声量增加6d B;将宽度方向开孔数从1孔增加到2孔,计权隔声量增加5d B;但当开孔数增加到一定值以后,继续增加则作用不再明显。

In order to explore the influence of the number of holes in hollow brick blocks and the way of hole arrangement on the sound insulation effect,the finite element method was used to analyse the sound insulation effect of two kinds of hollow brick walls with common thickness(115mm and 190mm),the influence of the number of openings in different length and width directions on sound transmission loss was compared,and the sound insulation trough was explained through modal analysis.The aim is to provide reference for sound insulation design of hollow brick block wall.The results show that the weighted sound transmission loss of 190mm thick hollow block wall is 6dB higher than that of 115mm.The sound transmission loss of hollow brick wall is 6-7dB lower than that of solid brick wall;the location of sound insulation trough depends on the vibration mode and displacement amplitude of eigen frequency.Increasing the number of holes in the length or width direction can effectively improve the sound transmission loss at the trough,and also improve the weighted transmission loss.By increasing the number of holes in the length direction from 2 to 4,the weighted transmission loss is increased by 6dB;as the number of openings in the width direction increases from 1 to 2,the weighted sound transmission loss is increased by 5dB;however,when the number of holes increases to a certain value,the effect is no longer obvious.