双层圆柱壳振动传递及近场声辐射特性研究

Research on the vibration passing and near-field acoustic radiation of double cylindrical shell

水下加筋圆柱壳体振动和声辐射是近年来研究的一个热点问题。文章从实验和数值计算两个方面,对水下加筋双层圆柱壳的振动传递及声辐射进行了研究。实验模型表面敷设了隔声去耦材料,分为四种工况:双壳全敷设、内全敷设、外全敷设、外部分敷设,对单频激振时内外壳体间的振动传递以及各工况下的近场声压进行了分析。结果表明,托板在内外壳的振动传递中起着较大的作用,内外壳全部敷设隔声去耦材料对抑制振动和声辐射最有效。为了减小托板对振动及声辐射的影响,提出了复合托板结构,即在托板上添加方钢结构,并对含复合托板的圆柱壳声学特性进行了数值研究,表明方钢在中高频段能有效降低壳体的振动及声辐射。

Finite cylindrical shells with stiffened ribs are major structure of cabin on the submerged or underwater vehicles. It has important theoretic value and practicality to research sound-vibration characteristic of the finite cylindrical shell with stiffened ribs. On the basis of experimental and numerical calculation, this paper studies the vibration and sound radiation of underwater ribbed cylindrical shell. Test model is coated with a kind of isolated and sound decoupled material. In four working conditions the vibration passing through the two shells and the radiated sound pressure are analyzed when the model is shocked by a single frequency. The result indicates that the brace has a great contribution towards vibration passing. Vibration and sound radiation are controlled effectively when the shells of the model are all coated with the isolated and sound decoupled material. A composite brace structure （including quadrate steel） is presented in order to reduce the influence of the brace on the vibration and sound radiation. The acoustic characteristic of double cylindrical shell including quadrate steel beam is analyzed as well. It shows that the quadrate steel beam can reduce the vibration and sound radiation of the underwater cylindrical shell effectively.