船体结构粘弹性夹层阻抑振动波传递特性研究

Research on Hull Structure Elastic Interlayer Impending Vibration Wave Propagation

基于波动理论分析了含粘弹性材料夹层的船体板架中振动波传递特性,给出粘弹性夹层对弯曲波的隔声量公式.同时将粘弹性夹层引入转角含阻振质量的典型船舶L型结构中,通过多次构造阻抗失配有效地阻断船体振动噪声主分量的传递.在此基础上,将这种复合隔振技术引入到动力舱段声学设计中并开展相应的数值实验.结果表明:粘弹性夹层对船体结构波具有较强的阻抑作用,夹层隔振性能随其杨氏模量降低及尺度增加而增大,夹层杨氏模量对隔声量的影响较其尺度更为显著,在刚性隔振基础上联合应用较小尺度的聚氨酯夹层可显著增加隔振效果并有效拓宽了隔振频带,具有较高的效费比.

Based on wave theory, the characteristics of elastic interlayer impeding vibration wave propagation from typical hull structure were analyzed, and the formula of its bending wave sound transmission loss was deduced. Furthermore, elastic interlayer were introduced into L-typed hull structure with blocking mass, the main factor of hull structure-borne sound could be reduced by structuring multi impedance mismatch. On this basis, the structure-borne sound design of power cabin with composite vibration isolation technique was verified through numerical calculation.The results show that elastic interlayer greatly attenuate the structure-borne sound, the isolation performance of interlayer is increased with Young＇s modulus reduction and its length addition.Combination of finite scale of polyurethane elastic interlayer with rigid vibration isolation can enhance the vibration isolation performance and continue isolation frequency band, which has a high cost-effective ratio.