舰船舷间双层声桥声振传递特性研究

Study on vibro-acoustic transmission characteristics of ship's double-layer acoustic bridge

[目的]双层壳之间的舷间结构是声振动从耐压壳向轻外壳传递的重要桥梁,为降低对舰船振动声辐射水平的影响,提出一种双层声桥的舷间结构形式并开展声振传递特性研究。[方法]采用有限元方法建立舷间双层声桥的有限长双层圆柱壳振动声辐射模型,对比分析双层声桥与传统单层声桥结构的声振传递特点,揭示双层声桥结构形式、结构参数以及轴向分布间距等因素对声辐射和振动传递特性的影响规律。[结果]对比结果表明:双层圆柱壳间的双层声桥连接结构比传统单层声桥结构的降噪效果更好;双层圆柱壳间“2-1”型双层声桥结构模型的振动传递降低效果优于“1-2”型和“2-2”型,而3种不同的“1-1”型双层声桥连接结构的振动传递降低效果则较为相近;底层声桥肋板间距和横铺板宽度对双层壳体结构的振动传递降低效果的影响较大,而声桥层高的影响则较小;双层圆柱壳间双层声桥的轴向分布越紧密,其振动传递降低的效果越差。[结论]研究成果可为舰船舷间结构的减振降噪设计提供参考。

[Objectives]The inter-ship structure between double-layer shells is an important bridge for the transmission of acoustic vibration from pressure shell to light shell.To reduce the impact on the acoustic vibra-tion radiation level of ships,a double-layer acoustic bridge inter-ship structure is proposed and its acoustic vibration transmission characteristics studied.[Methods]The finite element method is used to establish a finite-length double-layer cylindrical shell acoustic vibration radiation model of an inter-board double-layer acoustic bridge.The differences between the sound and vibration transmission of the double-layer acoustic bridge and those of a traditional single-layer acoustic bridge structure are compared and analyzed.Finally,the influence of the double-layer acoustic bridge's structure,structural parameters and axial distribution spacing on its acoustic radiation and vibration transmission characteristics is revealed.[Results]The results show that the double-layer acoustic bridge connection structure between double cylindrical shells has a better noise reduction effect than the traditional single-layer acoustic bridge structure.The effect of the"2-1"double-layer acoustic bridge structure model on reducing vibration transmission between double cylindrical shells is better than that of"1-2"and"2-2"double-layer acoustic bridge structures.Three different"1-1"double-layer acoustic bridge con-nection structures show similar vibration transmission reduction effects.The spacing of the bottom acoustic bridge ribs and the width of the transverse plate have a great influence on the vibration transmission reduction effect of the double-layer shell structure,while the height of the acoustic bridge has little effect.The closer the axial distribution of double-layer acoustic bridges between double cylindrical shells,the worse the vibration transmission reduction effect.[Conclusions]The results of this study can provide references for the shock absorption and noise reduction design of the inter-board structures of ships.