水下结构声固耦合振动的特征值计算

针对水下结构声固耦合振动计算中出现的非对称矩阵(与频率相关)的特征值问题,本文基于共轭子空间迭代法,提出了计算水下结构振动固有频率和振型的双重迭代算法.数值算例表明:该算法收敛性好,用于水下结构声固耦合振动的特征值计算是有效的.文中分别将流体视为不可压缩和可压缩两种情况建立了流固耦合方程,计算了板、加筋板和方箱振动的固有频率和振型,将干模态和湿模态、不可压缩流体和可压缩流体的计算结果进行了比较,并分析了结构刚度和流体边界条件对附加水质量影响系数的影响.

Computation of eigenvalues of acoustic-structural coupled vibration for underwater structures

To solve the eigenvalue problem for an asymmetric real matrix(dependent on frequency)in the computation of the acoustic-structural coupled vibration for underwater structures,the Dual Iteration Method to compute natural frequencies and shape modes of vibration for underwater structures is presented based on the Adjoint Subspace Iteration Method.Numerical examples show that the convergency of this method is good,which is effective in calculating the eigenvalues of the acoustic-structural coupled vibrta - tion for underwater structures.In this paper,two different fluid-structure coupled equations are established,according to the incompressible fluid and the compressible one respectively,and then natural frequencies and mode shapes of several structures including plates,stiffened plates and a cubic shell are computed.Finally,The shape modes in air and those in water and the numerical results based on the incompressible fluid and the compressible fluid are compared respectively.In addition,the effect of the structure stiffness and the fluid boundary conditions on the added mass coefficients is analyzed.