夹层边界上布置主动声学边界的有源隔声双层板结构

Active double-panel sound insulation structure based on the active acoustical boundary acting on the boundaries of air gap sound field

在双层板结构中夹层声场边界上布置平面声源作为主动声学边界,构成有源隔声双层板结构,提出基于主动声学边界方法的有源隔声双层板结构。在双层板结构中夹层边界上布置四边简支板,用来代替主动声学边界,控制力作用到该简支板上,采用声弹性理论建立了有源隔声双层板结构的计算模型,分别以辐射声功率最小和夹层声功率最小作为控制目标来优化控制力,计算分析控制前后夹层结构的传声损失以及各子系统的响应,并研究了主动声边界尺寸大小对系统隔声性能的影响。计算结果表明:主动声边界控制策略可以有效提高双层板结构的隔声性能,且以辐射声功率最小为控制目标要优于以夹层声场的声功率最小为控制目标;控制后,主动声边界对入射板振动响应几乎没有影响,辐射面板的振动动能和夹层声场的声功率均被有效地抑制;不同尺寸主动声边界都提高了夹层结构的隔声性能;对于低频率段,不同尺寸主动声边界对夹层结构的隔声性能提高的程度相同;对于其他频率段,主动声边界对传声损失和各子系统响应的影响并没有一定的规律,可以对主动声边界的尺寸进行优化设计,达到提高特定频段隔声性能的目的。

Based on the active acoustical boundary method,an active double-panel sound insulation structure was presented,which consists of a double-panel structure and an active acoustical boundary arranged on the boundary of the air gap sound field. Simply supported panels were used to replace the active acoustical boundary and were acted by control forces. In the light of the acoustoelsticity theory,an analytical model was developed to calculate the optimal control forces,considering the minimum radiation sound power and minimum air gap sound power as the control targets. On the basis of the developed theoretical model,the sound transmission loss（ STL） and responses of the subsystems of the active double-panel sound insulation structure were studied before and after control. Meanwhile,the effect of the dimensions of the active acoustical boundary on STL and responses of the subsystems were taken into account. The simulations carried out show that the active acoustical boundary control strategy can effectively improve the sound insulation performance of double-panel structures and the better control effect can be gotten with the target of minimum radiation sound power than that with the target of minimum air gap sound power. The active acoustical boundary has no influence on the vibration responses of the upper panel whilst the vibration responses of the lower panel and the air gap sound power are suppressed effectively. The active acoustical boundaries with different dimensions can all improve the sound insulation performance.Especially,in low frequency range,the same insulation performance can be gotten for the different dimensions,but in high frequency,range,the effect of the dimensions of active acoustical boundaries on the STL and responses of subsystems has no definite regularity,so the dimensions of the active acoustical boundaries can be optimized to improve the insulationperformance in certain specific frequency ranges.