Based on the Rayleigh integral, the vibro-acoustic characteristics of plates and stiffened plates mounted in an infinite baffle is discussed. The fluid-structure interaction equation is established by added mass, which is turned into by dynamic fluid force. Lanczos-QR algorithm is applied to solve unsymmetric generalized eigenvalue problem. Radiation power and radiation damping are obtained by structural surface velocity and energy ratio, respectively. The effects of fluid density and compressibility on the nature frequency and mode shape are discussed. Some numerical examples are used to discuss the influence of the fluid characteristics, compressibility, excitation location, plate thickness, stiffener types, and boundary condition on the acoustic characteristics, which are useful for prediction of vibration and noise.%以镶嵌在无限大刚性障板上的板和板加筋结构为研究对象,应用Rayleigh积分计算得到流体对结构的加载效应以附加质量的形式,叠加到有限元离散的结构动力方程中进行耦合.针对附加质量矩阵不对称的特点应用Lanczos-QR算法求取非对称阵的广义特征值和特征向量问题,基于结构表面振速计算声功率,并基于能量的概念计算声辐射阻尼.研究分析了流体可压缩性、附加质量计算频率、板厚以及加筋方式对板式结构的振动特性影响,和流体特性、激励位置、板厚、加筋方式、边界条件对板式结构的声辐射特性影响,为板和板加筋结构振动噪声预报提供了一定依据.
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