声-固耦合系统高频局部能量响应的FEM-SmEdA分析

The high-frequency local energy response for structural-acoustic coupling system by using FEM-SmEdA

针对高频激励下声-固耦合系统的局部能量响应预示问题,采用有限元(FEM)和统计模态能量分布分析(SmEdA)相结合的方法预示复杂声-固耦合系统局部能量响应.首先,以平板/声腔耦合系统为研究对象,验证FEM-SmEdA方法的准确性;随后,为了验证该方法的适用性,分别将该方法应用于湍流边界层(TBL)激励下平板/声腔耦合系统局部响应预示及加筋舱段/声腔耦合系统局部响应预示.利用双模态方程法(DMF)对基于FEM-SmEdA法的TBL激励作用下结构局部响应预示结果进行验证,基于FEM-SmEdA方法揭示TBL激励作用下舱段结构和声腔的能量分布随频率的变化规律,并研究加筋对声-固耦合系统能量分布的影响.结果表明:FEM-SmEdA 方法能够准确地预示高频环境下声-固耦合系统的局部能量响应;该方法适用于TBL激励下结构局部响应预示;随着分析频率的升高,舱段和声腔的能量分布更加均匀;加筋后结构的能量分布更加均匀,加筋对声腔能量响应的抑制更加明显.

By combining the finite element method (FEM) and the statistical modal energy distribution analysis (SmEdA), a FEM-SmEdA approach is presented to predict the local energy response of structural-acoustic coupling system under high fre-quency excitation. First,the accuracy of the FEM-SmEdA is verified by a plate/cavity coupling system. Then the approach is applied to a plate/cavity coupling system and a cabin/cavity coupling system under Turbulent Boundary Layer (TBL) excitation to verify its applicability respectively. The energy responses predicted by FEM-SmEdA are verified by Dual Modal Formulation (DMF) method. The influence of analysis frequency band and stiffener on the energy distribution of cabin/cavity coupling sys-tem under TBL excitation are investigated by the FEM-SmEdA. Results show that the FEM-SmEdA is capable of predicting the local energy response of structural-acoustic coupling system under the high frequency excitation with sufficient accuracy.This approach is well adapted for predicting the local response of systems under TBL excitation. With the increase of analysis frequency band.the energy distributions of cabin and cavity become more uniform.The energy distribution of stiffened cabin/cavity coupling system is more uniform than that of cabin/cavity coupling system.The suppression of stiffener to response of cavity is more obvious than structure.