用耦合有限元／边界元方法研究加筋板的声传输

采用耦合的有限元／边界元方法，建立了考虑流体结构耦合的加筋板结构声传输计算模型，并利用该模型计算研究了加筋板的声传输特性。数值计算表明：结构的传声损失与结构的固有频率和激励频率密切相关，避免共振仍是产要的；改变板厚或肋骨惯性矩后，由于结构固有频率发生了变化会使得结构传声损失曲线上极小值的位置发生改变；当声波从空气经结构向空气中传递时，增大板厚或肋骨惯性矩可明显增大结构的传声损失；而当声波从空气经结构向水中传递时，增大板厚或肋骨惯性矩也增大了结构的传声损失，但效果明显不如当声波从空气经结构向空气中传递时显著。

Coupled FEM/BEM Approach for Analysis of Sound Transmission through Stiffened Plates

The computational model of sound transmission through a stiffened plate excited by a harmonic oblique incident plane wave and mounted in an infinite baffle using the coupled finite element/boundary element approach is presented. The finite element method is used to model the structure and the boundary element method based on the Rayleigh integral on the plate surface is employed for the acoustic fluid. The proposed model takes the acoustic fluid structure coupling into account. The sound transmission losses through stiffened plates are calculated and discussed with the proposed model. The numerical results show that: the sound transmission losses are closely dependent on the natural frequency of the structure and the excitation frequency and it is important to detune the structural resonant frequency away from the excitation frequency; the position of minimum values of the sound transmission losses curve varies with the changes of the structural nutural frequencies after modifying plate thickness and moment of inertia of stiffeners; an increase in the plate thickness or the moment of inertia of stiffeners reduces the sound transmission through stiffened plates markedly from air to air and mildly from air to water.