文献类型：会议论文

英文题名：Effect of geometry factors on dynamic fracture behavior for mechanical heterogeneous welded joint

作者：Tian, Fuqiang[1];Li, Xiaoyan[2];Shi, Yaowu[2]

机构：[1]East China Univ Sci & Technol, Sch Mech & Power Engn, Shanghai 200237, Peoples R China;[2]Beijing Polytech Univ, Sch Mat Sci & Engn, Beijing 100022, Peoples R China

会议论文集：5th International Conference on Fracture and Damage Mechanics

会议日期：SEP 13-15, 2006

会议地点：Harbin, PEOPLES R CHINA

语种：英文

外文关键词：dynamic J-integral; mechanical heterogeneity; welded joints

摘要：Welded joint is a mechanical heterogeneous body, which is composed of base metal, weld metal and heat affected zone (HAZ). Many welded structures endure dynamic load in service. Mechanical heterogeneity has important influence on dynamic fracture behaviour of welded joint. In the present investigation, dynamic fracture parameter of J-integral of undermatched three-point-bending (TPB) welded joint specimens containing longitudinal crack with different geometry were computed. The strain rate near crack tip reaches 10(3) under the impact velocity of 5 m/s, so dynamic properties under corresponding strain rate should be used in dynamic analysis. The results of instrumented impact experiment were used as the input parameters in the computation. Dynamic J-integral was evaluated using virtual crack extension (VCE) method of MARC finite element code in 3-D condition. Dynamic J-integral evaluated by VCE method is path independent. The value of dynamic J-integral curve increases with loading time smoothly, so inertia force has little influence on dynamic J-integral. The values of dynamic J-integral decrease with increase of weld width. When the weld width is bigger than 5 mm the influence of base material on weld metal is not evident. The influence of initial crack length on dynamic J-integral is complicate. The value of dynamic J-integral of the computation model with initial crack length of a/W=1/4 is the highest, and that of the computation model with initial crack length of a/W=1/8 is the lowest. The results are helpful for dynamic fracture evaluation of macro-heterogeneous welded joints.