Analysis of Limit Loads for CT Specimens with Cracks Based on Extended Finite Element Method

XFEM is a newly proposed method which can simulate the crack growth process. Limit load analysis for CT specimen with different crack size is performed in this paper. Firstly calculation results demonstrate that the curve of load-COD based on XFEM will decrease when the load reach a maximum value, which agrees well with the experimental results. And limit load results from XFEM are compared with other methods and criteria like EPRI method, two-elastic slop method and JIC criterion, from which it can be found that XFEM is a useful method to calculate limit load for cracked structures. Finally by the advantage of XFEM that can simulate the crack extension process, a non-linear relationship between the amount of expansion of cracks and COD at the beginning of extending, and a linear relationship at the stable extending stage based on XFEM are obtained.