基于SBFEM的多裂纹问题断裂分析

Fracture analysis of multiple crack problems based on SBFEM

多裂纹问题中的应力强度因子是断裂力学中需要计算的重要参数.在子结构法思想的基础上利用比例边界有限元法计算了弹性多裂纹问题的I型裂纹应力强度因子.对于多裂纹的弹性问题根据裂纹的数目确定相似中心的数目,在每一个子块内保持比例边界有限元法的特点.利用该数值技巧可以求解任意多裂纹问题的应力强度因子,数值算例表明该方法是有效且精确的.最后给出了正交各向异性材料双边非对称裂纹问题的计算结果,进而推广了比例边界有限元法的应用范围.

The stress intensity factor of multiple cracks problems is an important issue in elastic fracture mechanics. The scaled boundary finite element method （SBFEM） is proposed to deal with this kind of problem. The solution of stress intensity factor of modeⅠ of multiple crack problems is presented. The whole domain is partitioned into several sub-domains according to the number of existing cracks. Each sub-domain has its own scaling center. At the same time, the characteristics of the SBFEM is preserved in each sub-domain. Numerical examples show that the SBFEM is effective with high accuracy in dealing with the multiple cracks fracture problems. It can be employed to treat the anisotropic medium easily. The results of the stress intensity factors of unequal double-edged cracks in orthotropic material are presented. The scope of application of the SBFEM has been extended.