含裂纹弹性结构声相互作用研究

应用分形有限元和边界元相结合的方法研究了含裂纹的结构声的耦合作用问题。利用二级分形有限元方法离散含裂纹结构,这将使得自由度大为减少;使用边界元方法计算外域辐射声场,这将自动满足无限远辐射边界条件。数值结果初步表明:(1)随着裂纹深度的增加,结构声耦合系统的共振频率将下降;(2)裂纹附近的声场所受的影响更为明显。

Analysis on cracked structure-acoustic interaction problems

The mixed method of boundary element and fractal finite element is adopted to solve the cracked structure-acoustic coupling problems. The fractal two-level finite element method is employed to model the cracked structure, which can reduce the degree of freedoms greatly, and the boundary element method is used to evaluate the exterior acoustic field which can satisfy automatically infinity radiation condition. Numerical examples show that the resonance frequency is lower with the depth of the crack increase, and the effect on the acoustical field by the crack is particularly pronounced in vicinity of the crack tip.