双层加筋板低频声的隔离与有源控制

Passive and active low frequency sound insulation effects of rib stiffened double-panel structure

为探讨加筋对双层结构低频隔声及有源控制的影响,分析了筋条数目及布放位置对双层加筋结构低频隔声性能、有源控制策略选取及有源隔声性能的影响。首先利用模态叠加与声-振耦合理论对双层加筋结构建模,然后采用数值算例对上述问题展开探讨。研究发现,筋条数目增多或筋条靠近基板的中间位置布放,将有利于双层加筋结构低频隔声性能的提高。对于有源控制措施,声控制策略与力控制策略相比,前者的控制效率较高且降噪效果较好。由于筋复杂的耦合影响,添加多条筋或筋条靠基板中间布置时有源控制效果减弱,需施加多个点源才能获得较好的降噪效果。

The influences of different rib numbers and its arrangements on low frequency passive sound insulation, the selection of active control strategy and active control effects of rib stiffened double-panel system are investigated numerically. The theoretical model of rib stiffened double-panel system is firstly established using a combined modal expansion and vibro-acoustic coupling methods. Then the above issues are analyzed in detail by numerical simulations. It is concluded from investigation that the number of the resonant modes of the ribbed plate will become smMler in the low frequency range of interest when the number of ribs increases or the location of the ribs approaches the middle of the base plate. This is helpful for improving the overall low frequency sound insulation of the system. As for the active method, the control efficiency and noise reduction obtained by cavity control strategy are better than that obtained by panel control strategy. Due to the complex coupling effects of the ribs, the active control effects become worse when the number of ribs increases or its location approaches the middle of the base plate. More secondary sound sources are needed in this case to gain preferable noise reduction.