부산대학교 도서관

Extended finite element method (XFEM) can effectively describe the phenomenon of steel node cracks growth and extension. In this paper, extended finite element method is used for the beam weld node end under the concentrated load to analyze node fracture under no initial crack and pre-crack condition. The result shows that: under the no initial crack condition, crack appears near the weld root, where the bottom and upper of the weld is easy to crack than the middle,because of the necking phenomenon,which means that both end stress is higher than the middle. Crack firstly appears in the weld bottom, extending from the bottom to up. The crack tip makes stress concentration, which accelerates the crack extension. The location of the pre-crack has the influence on the node fracture, which means that the farther the position from the weld root is, the harder it is to crack and grow. Pre-crack position coincides with no initial crack extension path, promoting crack growth and extension.