含局部预应力的圆柱壳结构声辐射特性分析

以圆柱壳结构-声辐射特性为研究对象,分析了局部预应力对结构动力学特性的影响.基于Flügge圆柱壳薄壳理论,建立了含局部预应力的圆柱壳结构应力-应变方程,应用变分原理推导了含局部预应力的圆柱壳结构动力响应方程.结合结构有限元和声边界元法,对圆柱壳结构的声辐射问题进行数值分析,对比了预应力对声辐射功率和声指向性的影响.结果表明,由于局部预应力的存在,使得结构的局部和总体刚度都发生变化,并引起结构声振特性的变化.

Characteristics Analysis of Structural-Acoustic of Cylindrical Shell with Prestress in Local Areas

The influence of existing prestress on structure dynamic response and acoustic radiation were investigated. Based on Flügge’s cylindrical shell equations, the strain-displacement equation with prestress in local areas was discussed, and the structural-acoustic mathematical formulation for cylindrical shell with prestress in local areas was propored by using the variational principle. By using finite element method (FEM) and boundary element method (BEM), the numerical analysis of structural-acoustic radiation for shell structure was presented, and the influence comparison of prestress on acoustic radiation power and acoustic radiation directivity was conducted. The results show that with the existing of prestress in local areas leads to a change of local areas stiffness matrix, and the overall stiffness matrix of cylindrical shell is altered. The prestress has a significant impact on dynamic characteristics of cylindrical shell structure.