板-腔耦合对腔体共振频率的影响  

The effect of the plate-cavity coupling on the resonance frequency of the cavity

作　　者：张晓排[1,2] 邱小军[1] 

机构地区：[1]近代声学教育部重点实验室,南京大学声学研究所,南京210093 [2]大连交通大学交通运输工程学院,大连116028

出　　处：《南京大学学报（自然科学版）》2012年第1期8-14,共7页Journal of Nanjing University（Natural Science）

基　　金：国家自然科学基金(11004100);南京大学近代声学教育部重点实验室(1004);中央高校基本科研业务费专项基金(1101020402)

摘　　要：基于模态展开法建立板-腔耦合系统受迫振动响应模型,以分析耦合后腔控模态共振频率的偏移.理论分析和仿真发现,与小阻尼近刚性壁面比,弹性板相对较小的声质量使得耦合后腔体共振频率发生偏移,偏移量的大小和方向与板-腔耦合系统的模态耦合系数、板的声质量和板模态共振频率有关.若腔共振频率高于板共振频率,耦合后腔控模态共振频率增加;若腔共振频率低于板共振频率,耦合后腔控模态共振频率减小;通常最大模态耦合系数决定了腔共振频率偏移量的大小.The forced response of an acoustic-structural coupled system has been modeled to analyze the resonance frequency shift of a cavity controlled mode.Theoretical analysis and simulations show that unlike the infinite acoustical mass of the approximately rigid wall with a slight damping,the finite acoustical mass of the plate allows the plate-cavity couple,resulting in the resonance frequency shift of the cavity controlled mode.The degree and direction of the shift are affected by the modal coupling coefficient,the acoustical mass of the plate and the resonance frequency of the plate.If the resonance frequency of the uncoupled cavity mode is higher than the resonance frequency of the uncoupled plate mode,the cavity controlled frequency increases after the plate mode and the cavity mode are coupled,and vice versa.Usually the maximal modal coupling coefficient plays a dominant role to the degree of the resonance frequency shift of the cavity controlled mode among all coupling coefficients of the cavity with the plate modes.

关 键 词：流固耦合 声质量 共振频率 

分 类 号：TN248.1[电子电信—物理电子学]