一种分析周期加筋板声辐射的高效方法

为了研究周期加筋板的声辐射特性,建立了一种计算水中周期加筋板在简谐点力作用下的远场辐射声压的高效方法。该方法借助于傅里叶变换法只要先将耦合系统的声振方程,加强筋的弯曲和扭转运动方程,声学波动方程和耦合边界条件转换到波数域中,联合求解得到一组关于平板横向位移的无限大耦合代数方程组,再将该方程组截断成有限大小由数值方法求出波数域中的位移响应,便可结合稳相法得到远场辐射声压。与现有方法给出的结果对比发现二者完全吻合,验证了本文方法的有效性;通过数值方法研究了激励力位置、板厚,加强筋间距和宽度对周期加筋板声辐射特性的影响,得到了具有实际意义的结论。

An efficient method to investigate the sound radiation from a periodically stiffened plate

To analyze the sound radiation characteristics of a periodic stiffened plate,an efficient method to calculate the far field radiated sound pressure from the stiffened fluid-loaded plate excited by a time-harmonic point force is present. In this approach,the vibro-acoustic equation of the coupled system,the bending and torsional motion equation of the stiffeners,acoustic wave equation and the fluid-structure coupled condition in physical space are firstly transformed to the wavenumber domain by using the Fourier Transform method.By solving these equations together,yields an infinite set of algebraic coupled equations about the transversal displacement of the plate in wavenumber domain,which is numerically solved by truncating them in a finite range.At last,combining with the stationary phase method,the far field radiated sound pressure can be calculated.Validation of the present method is performed by comparing the present predictions with that given by existing method,perfect agreements are achieved.The influences of the excitation locations,thickness of the plate,the periodicity spacing and width of the stiffeners on the sound radiation characteristic of the periodic stiffened plate is numerically quantified and conclusions of significant practical implications are drawn.