弹性基础上的双层隔振结构声辐射的主动控制

Active noise control for sound radiated from flexible base of a two-stage vibration isolation system

采用阻抗导纳法建立了以弹性矩形板为基础的双层主动隔振系统数学模型。以基础向外的声辐射为控制对象,探讨不同前馈控制策略的声辐射主动控制效果。分别选取两种面向振动及两种面向声辐射的控制性能函数,考察施加控制后弹性基础的辐射声功率,并综合考虑声压分布及控制力幅值等参数对控制效果进行全面地分析比较,进而评价各控制策略的优劣。结果表明,由于结构振动的耦合作用,面向振动的控制策略会恶化某些频段基础向外的辐射声功率,而直接面向声辐射的控制策略则可能会以放大振动响应或需要大的控制力为代价。最后,还对控制力作用位置对控制效果的影响进行了探讨。

In order to evaluate control performances of different feed-forward control strategies for sound radiated from the flexible base of a two-stage vibration isolation system,a mathematical model of a two-stage vibration isolation system mounting on an elastic rectangular plate was established.Two vibration-oriented cost functions and two sound radiation-oriented ones were chosen and the acoustic radiation power of the plate after control was investigated.Further more,the control effects were comprehensively analyzed by taking parameters like sound pressure distribution,and control force amplitude into account.Then the advantages and disadvantages of different control strategies were evaluated.The simulation results showed that the vibration oriented control strategies may lead to increase in the radiated sound power at specific frequencies while the sound radiation-oriented control strategies may amplity vibration responses and need a larger control force amplitude.In addition,the influence of the location of control force on the control effect was studied.