摘要
阻隔质量是结构噪声控制的一项重要技术。从波传播的研究出发,推导了具有阻隔质量的无限长杆类结构中纵波的无量纲化传递损失公式,分析了阻隔质量对纵波的传递损失特性。开展了阻隔质量技术对杆类结构纵波隔离的工程应用研究。理论分析表明,阻隔质量对纵波的传递损失仅与无量纲化频率α(阻隔质量与单位波长杆的质量之比的2π倍)有关,传递损失随着α的增加而增加。在阻隔质量技术对纵波隔离的工程应用中,传递损失仅受阻隔质量与单位长度杆的质量之比β控制,与杆的横截面形状无关。对钢杆而言,当β=2,4时,分别在1000Hz和500Hz处可以取得将近4dB的传递损失。对硬橡胶杆而言,当β=2,4时,分别在1000Hz和500Hz处可以取得将近12dB的传递损失。
Blocked mass is an important technique for the control of structural noise. Based on the research of wave propagation, the formulation of transmission loss for longitudinal wave of an infinite rod with a blocked mass is derived. The characteristics of transmission loss are analyzed. The results of theoretical analysis show that transmission loss for longitudinal wave is relevant to non -dimensional frequency. As non - dimensional frequency increases, transmission loss increases. In the engineering application of blocked mass, transmission loss is controlled by the ratio of blocked mass to the mass of the rod with unit length, and has no relevance to the shape of the rod. Whenβ = 2,4, for steel rod, 4dB transmission loss may be approximately obtained at 1000Hz and 500Hz respectively. Whenβ = 2,4, for rubber rod, 12dB transmission loss may be approximately obtained at 1000Hz and 500Hz respectively. There are two ways to improve the transmission loss for longitudinal wave.
出处
《噪声与振动控制》
CSCD
北大核心
2006年第6期54-57,共4页
Noise and Vibration Control
关键词
声学
杆
阻隔质量
纵波
传递损失
acoustics
rod
blocked mass
longitudinal wave
transmission loss
