采用波叠加法技术求解加肋板的辐射声功率

摘要

A method for calculating the radiation sound power of a stiffened plate was proposed using the principle of wave superposition. First of all, Fourier transform or element volume-velocity match was applied to the structural dynamic equation, and the volume velocity of the structure elements was obtained. According to the compatibility condition between the structure and the medium, a set of algebraic equations was established for calculating the virtual sound source intensity and the element volume velocity. Furthermore, the virtual sound source intensity could be used to compute the radiation sound power of the structure. Two methods were provided which can be used to compute the sound power of the stiffened plate without computing the surface pressure. As an example, the structural radiation sound power of a rectangular simply-supported baffled plate was computed. The result was compared with that of the analytical solution. It is shown that both the methods have high precision. Since the method based on the element volume velocity matching principle does not need to calculate the vibration modal coupling matrix, it is more straightforward and simple than the method using Fourier transform.%波叠加原理提供了计算加肋板辐射声功率的方法。首先对结构的动力方程进行Fourier变换或者单元体积速度匹配，获得结构离散单元的体积速度。然后根据结构与介质的交界面相容性条件，建立虚拟声源强度与单元体积速度的代数方程。进而求解虚拟声源的强度，获得计算结构辐射声功率的两种方法。以求解加肋简支矩形板的声功率为例，其结果与解析法获得的结果进行了对比，表明这两种方法都同样具有较高的计算精度。相对于利用Fourier变换的方法，采用单元体积速度匹配原则的方法不需要计算结构的振动模态耦合矩阵，计算简单直接，而且行之有效。