水下双层圆柱壳全频段声振特性研究

摘要

为研究水下双层圆柱壳结构全频段声振特性,基于VA-ONE建立了FE-BEM混合法、FE-SEA混合法及SEA法3种不同的计算模型,进行了不同辐射介质中辐射声功率及外壳振速的计算,并进一步研究了内外壳及肋板厚度、约束条件、激励位置及层间流体对双层圆柱壳声辐射特性的影响;基于FE-BEM混合法研究了圆柱壳结构的声散射特性;研究了肋板在结构振动能量传递中的作用,提出了2种阻尼肋板的减振降噪方案并进行相关仿真分析.结果表明:重流体能够抑制结构的振动,但由于重流体声阻抗较大,结构的辐射声功率变大;结构声散射曲线在某些频率处出现峰值,且峰值频率与结构自身的固有特性有关;阻尼肋板能得到较好的减振降噪效果,工程上建议使用金属聚氨酯阻尼肋板.%In order to study the acoustic vibration characteristics of underwater double layered cylindrical shells in the whole frequency band, three different calculation models are established based on VA-ONE, which are hybrid FE-BEM method, hybrid FE-SEA method and hybrid SEA method; the radiated sound power and the vibration velocity of the shell in different radiation medium were calculated. The effects of inner and outer shell and ribbed plate thickness, constraint condi-tion, incentive position and inter layer fluid on the sound radiation characteristics of double cylindrical shell are further stud-ied. Study acoustic scattering characteristics of double cylindrical shell structures based on FE-BEM hybrid method. The function of the ribbed plate in the structural vibration energy transmit is further studied, put forward two vibration and noise reduction schemes of damping boards and carry out corresponding simulation analysis. The results show that heavy fluid can suppress the vibration of structure, however, because of the large acoustic impedance of the heavy fluid, the radiated sound power of structure becomes larger. The peak value of the structure acoustic scattering curve appears at some frequencies, and the peak frequency is related to the inherent characteristics of the structure itself. The damping ribbed plate can get better vi-bration and noise reduction effect, metal polyurethane damping ribbed plate is recommended to use in engineering.