水下湍流激励复合材料板的振声特性研究

Study on underwater vibro-acoustic characteristics of composite plate induced by TBL

为有效控制水下复合材料结构受湍流壁面脉动压力激励引起的结构自噪声,利用模态展开技术和高阶剪切形变理论,结合湍流壁面脉动压力功率谱建立了水下湍流壁面脉动压力激励复合材料板的Rayleigh-Ritz模型,并推导了结构振声响应的封闭解.利用该方法探讨了复合材料板的弹性模量、密度、阻尼等材料参数,以及铺层角度和厚度等参量对水下湍流激励引起结构振动和声辐射的影响.研究发现:通过增大结构阻尼是抑制水下湍流壁面脉动压力激励复合材料板的振声响应的最佳有效途径,同时提高结构抗弯刚度也能达到较好的减振降噪效果,尤其在抑制振动方面作用显著.

In order to effectively control the self-noise of underwater composite structure induced by turbulent boundary layer(TBL) pressure fluctuations,the Rayleigh-Ritz model of underwater composite plate excited by TBL was established with the modal expansion technique and the theory of high order shear deformation,combined with the power spectrum of TBL. Then,the influence of material parameters such as elastic modulus,density and damping of composite plate,as well as parameters such as layerangle and thickness on structural vibration and sound radiation induced by TBL was discussed.The study indicates that,increasing the structural damping is the best and effective way to control the self-noise of underwater composite structure induced by TBL.Further more,the high flexural rigidity of the structure can also achieve good effects of vibration and noise reduction,especially making a significant contribution to vibration elimination.