声辐射问题的二级分形有限元方法

利用分形有限元和常规有限元相结合的方法对中低频段声辐射问题进行了分析，由于引用了分形比α和能够自动满足无限远辐射边界条件的全域插值函数，大大降低了未知量的个数，从而可以在较短的计算时间和较低的内存消耗的条件下高效地解决问题，计算实例表明这种方法对于求解无界域声场问题是有效的。

FRACTAL TWO LEVEL FEM FOR ACOUSTICAL RADIATION PROBLEMS

The propagation and attenuation of acoustic waves in exterior domains is an essential ingredient in the study of acoustic-structure interaction. In this paper the problems of acoustics radiation in infinite exterior region are investigated by using the method of fractal finite element combined with conventional finite element. By introducing the global interpolation functions which satisfy automatically the infinite radiation conditions, the large number of unknowns, and the computer time and memory can be decreased greatly. Numerical examples show that this method is effective in solving unbounded acoustic problems.