壳间连接介质对双层壳声辐射性能的影响

研究了不同壳间连接介质的加筋双层壳的振动声辐射特性.基于Flügge壳体理论和Helmholtz波动方程,求解了双壳体声-流体-结构耦合方程,计算了有限长双层壳体在径向点激励下的声功率和振动速度级.结果表明,水层的耦合作用随频率的增高而降低,托板的耦合作用随频率的增高而增加,托板在内、外壳的振动传递中起着较大的作用.为了减小托板对振动及声辐射的影响,提出了阻尼托板结构,即在托板上添加阻尼材料,对含阻尼托板的圆柱壳声学特性进行了数值研究.结果表明,在中高频段,阻尼有效抑制了振动能量的传递,壳体的辐射声压明显降低,这对水下结构的减振降噪设计具有重要的参考意义.

The effect of linked materials on the sound radiation from double cylindrical shell

The sound radiation from the stiffened double cylindrical shell with different linked materials is studied.Based on Flügge shell theory and Helmholtz equation,the vibration equation coupled by the sound-fluid-structure is solved,and the radiated power and radial quadratic velocity are calculated for the finite double shell driven via a radial point force.The result shows that the coupled effect of water layer declines and the coupled effect of brace increases with the increment of frequency.The brace has a great contribution towards vibration passing.A damping brace structure(including damping layer) 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 damping brace is analyzed.It shows that for medium and high frequencies the transmission of energy is depressed by damping material,and the radiation pressure is reduced remarkably.