在降低结构振动噪声方面,结构声学优化方法展现了很高的应用潜力,并越来越受到研究者们的重视.通过结构声学敏感度分析建立辐射声场与结构材料属性和结构形状参数的关系,结合优化算法可设计出低辐射噪声和高声隐身性能的水下航行结构.发展耦合有限元法与快速多极高阶非连续边界元法进行流固耦合问题的敏感度分析,克服传统耦合算法的计算精度低,内存占有量高,难以进行大规模实际问题的计算等问题.设计变量可选为流体密度、结构密度、泊松比、杨氏模量、壳厚度和形状参数等.针对不同设计变量,采用直接微分法分别推导出结构声学系统和辐射声功率敏感度表达式.通过带有解析解的水下点激励球壳算例验证算法的正确性与有效性,并通过简化潜艇算例展示该算法在大规模实际问题上的应用潜力.%The structural-acoustic optimization method receives more attention of designers due to its high potential in reducing structures'' vibration and noise.The structural acoustic sensitivity analysis can be used to establish relations among radiated acoustic field, structural material properties and structural shape parameters, then unwater navigating structures with lower radiated noise and higher sound-stealth performance can be designed with the optimization method.Here, the coupled algorithm was developed by combining FE and fast multi-pole higher order discontinuous BE to perform the sensitivity analysis for fluid-structure interaction problems.The developed algorithm improved the calculation accuracy and decreased the memory storage.Fluid density, structural density, Poisson''s ratio, Yong''s modulus, structural shape size and so on were taken as design variables.The sensitivity formulas for structural-acoustic system and radiated sound power with respect to different design variables were derived based on the direct differentiation method, respectively.A numerical example for an underwater spherical shell under a point excitation with an analytical solution was used to verify the validity and correctness of the developed algorithm, and an example for a simplified submarine was used to show the application potential of the developed algorithm in large scale practical problems.
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