弹性体裂纹扩展的数值模拟

Numerical Simulation of Crack Propagation of Elastic Body

采用位移不连续法 (DDM)对裂纹的扩展进行了数值模拟 .首先应用 DDM求解了线弹性裂纹体的应力场 ,再采用最小二乘法确定应力强度因子并根据线弹性复合型断裂判据进行开裂判断 ,从而实现裂纹开裂的模拟 ,取得了与实验结果较吻合的数值计算结果 .文中所用方法仅需在裂纹面上直接划分单元、对开裂部分直接追加单元来实现裂纹扩展过程的动态跟踪 。

The propagation of a linear elastic crack was simulated by displacement discontinuity method(DDM). Firstly, the stress field is solved for a linear elastic crack using DDM. Then to judge whether the crack would propagate, the linear composed fracture criterion is applied. The numerical results are compared with the experimental results, which show satisfied consistency. Those structural boundaries including crack surface need to be discreted when solving the stress field using DDM, so the nodes involved are much less. During the crack propagation, it is not necessary to do meshing again. DDM is more suitable for simulating crack propagation. Considering the above merits, the method can be generalized and put into good use in simulating the propagation of arbitrary cracks in a linear elastic body.