典型船舶结构中振动波传递特性研究

Characteristics of vibration wave propagation in typical hull structure

以波动理论为基础,根据不均质结构中波型转换、阻抗特性,系统地分析了典型船舶结构中振动波的传递特性,推导并给出了平面弯曲波入射时的隔声量公式。在此基础上人为构造了阻抗失配基座,分析了阻抗失配基座的隔振性能。结果表明,十型结构对弯曲波有较强的阻抑作用,弯曲波在突变截面处的能量再分配关系主要由两块板的特性阻抗所决定;■型构件的连接处机械阻力较大,其隔振效果超过十型结构;■型结构隔振性能随突变截面阻抗失配程度增大显著提高,采取多次截面突变的办法能够得到较大的隔声量;阻抗失配基座加剧了振动波在船体板架中的波型转换、散射和反射,使总的隔振效果显著提高。本文旨在为船舶结构声学设计提供参考。

Based on wave analysis method, the characteristics of vibration wave propagation in typical hull structure were analyzed in consideration of wave type conversion and impedance variation in non-homogeneous structure, and the formula of sound transmission loss during incidence of plane bending wave was deduced. On this basis, the influence of impedance-mismatched ship foundation on isolation performance was discussed. The results show that 十 type structure greatly impedes the bending wave propagation, and the redistribution of bending wave at mutated-section is mainly determined by natural impedance of the two plates. The resistance at the connection of ■ type structure increases and its isolation performance is better than that of 十 type structure. The isolation performance of ■ type structure obviously becomes better with the increase of impedance mismatch level at mutated-section, therefore more sound transmission loss can be get by bringing in a number of cross-sectional mutations. The impedance-mismatched base aggravates type conversion, scattering and reflection of vibration wave in hull plates, so the total isolation performance improved significantly.