The interaction between the sound field outside an elastic structure and its boundary is of paramount importance in the field of acoustics. This paper describes the global acoustic impedance in the form of impedance integral operator and impedance matrix for the analysis of elastic structures. In general, the excitation applied locally to the structure can induce vibration on the entire structure surface and hence the global acoustic impedance is introduced to characterize the relationship between the resultant sound pressure and acoustic particle velocity. The main advantage of the global acoustic impedance over the local acoustic impedance is that it facilitates improved physical insights into the sound field due to the presence of excitation sources. Furthermore, the acoustic impedance of an elastic spherical shell in matrix form is solved and analyzed by solving the finite element equation of structural dynamics with programming techniques. The impedance matrix is subsequently taken as the boundary condition to investigate the acoustic scattering from the elastic shell structure using the acoustic boundary element method. Explanations for the difference between the acoustic scatterings calculated based on the global acoustic impedance and the local acoustic impedance are offered.

中文翻译：

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用于分析弹性结构声散射的全局声阻抗

弹性结构外部的声场与其边界之间的相互作用在声学领域中至关重要。本文以阻抗积分算子和阻抗矩阵的形式描述了用于弹性结构分析的全局声阻抗。一般来说，局部施加到结构上的激励可以在整个结构表面上引起振动，因此引入全局声阻抗来表征合成声压和声粒子速度之间的关系。与局部声阻抗相比，全局声阻抗的主要优势在于，由于存在激励源，它有助于提高对声场的物理洞察力。此外，采用编程技术求解结构动力学有限元方程，求解和分析矩阵形式的弹性球壳的声阻抗。随后将阻抗矩阵作为边界条件，使用声边界元法研究弹性壳结构的声散射。解释了基于全局声阻抗和局部声阻抗计算的声散射之间的差异。