复合结构隔声理论分析与实验特性研究

基于无限大分层介质波传递理论,采用传递矩阵方法和声能量分布理论,开展了水下复合阻尼结构隔声特性的研究。仿真结果表明橡胶材料属性对结果隔声有很大的影响。软和小泊松比的橡胶可以明显提高结构的隔声特性。多层橡胶复合结构在隔声方面比单层复合结构具有更大的优势,在多层橡胶中打孔可有效提高结构的隔声性能。空腔越多,隔声特性越好。蜂窝三明治复合结构的隔声特性要好于含圆柱空腔复合结构的隔声性能和多层均匀复合结构。结合现有的试验条件,在消声水池开展了蜂窝三明治复合结构自由场大样测试,实验结果表明,测量值与理论预测有很好的一致性。

Numerical analysis and experimental study of sound insulation performance of underwater viscoelastic coated compound structures

Based on wave transfer propagation theory in infinite layered medium,sound insulation performance for underwater compound damping structures(basic materials are rubber and steel) is investigated using transfer matrix method and percentage distribution of sound energy in certain area.Simulations show that the property of rubber material influences sound insulation of structure greatly.Soft rubber as well as those with small Poisson's ratio may improve sound insulation performance of the whole structure remarkably.Multi-layered rubber compound structures outperform mono-layered ones.It's a good way to make cavities inside multi-layered rubber compound structures for improving sound insulation property.The more the cavities are,the better sound insulation will achieve.As a particular kind of complex multilayered rubber compound structures,honeycomb sandwich rubber compound structure has better sound insulation property than rubber interlayer with cylindrical cavities compound structure and homogeneous rubber compound structure.To confirm theoretical analysis,many measurements of freedom-field of honeycomb sandwich compound structure have been carried out in anechoic water tank.The measurement results have good agreement with theoretical prediction.