声散射问题的一种新的无限元方法

A new infinite element method for acoustical scattering problems

声波在无限大外域中的传播和衰减问题是研究声与结构相互作用的重要基础.本文提出了一种新的声无限单元耦合有限元方法于外域声散射问题的计算.应用加权残值法推导了声无限单元的刚度矩阵和质量矩阵,选取的形函数及权函数充分考虑了外域声传播的基本特点及无穷远辐射边界条件.计算实例表明这种方法对于求解无界域声场问题是非常有效的.

The propagation and attenuation of acoustic waves in exterior domains is the essential ingredi ent in the study of acoustic-structure interaction. In this paper the problems of acoustics scattering in infinite exterior region are investigated by using the method of infinite element method combined with conventional finite element method. The stiffness and mass matrixes of the infinite element are developed by applying residual weighting methods. The basic character of acoustic propagation in exterior domain and the infinite radiation conditions are fully taken into consideration in choosing the interpolation shape functions and weighting functions. Numerical examples are performed, which illustrate the effectiveness of this presented method in solving unbounded acoustic problems.