作者：孔令圳, 帅健, 周夏伊
作者单位：中国石油大学(北京)机械与储运工程学院, 北京 102249
关键词：断裂力学; 裂尖约束; Gurson孔洞模型; 裂尖轨迹; CTOA
摘要：
针对实验研究约束不易操作、难以测量的状况,采用有限元Gruson孔洞模型建立SENB试件、CT试件和MCT试件的有限元模型,研究试件类型、厚度对裂尖轨迹的影响,以及试件厚度、裂纹扩展量和约束表征参数对裂尖约束的影响。研究结果表明:试件类型对于裂尖轨迹影响较小,试件厚度对裂尖轨迹影响显著;约束沿厚度方向和裂纹扩展方向变化明显,全局约束因子g和应力三轴度Am等效,该结论对CTOA测试及理论分析有较大的理论价值和指导作用。
Constraint analysis in CTOA test
KONG Ling-zhen, SHUAI Jian, ZHOU Xia-yi
College of Mechanical and Transportation Engineering, China University of Petroleum-Beijing, Beijing 102249, China
Abstract: The SENB specimens, CT specimens and MCT specimens were modeled using the Gurson model. The effects of the type of specimen and the specimen thickness on the crack tip trajectory, the effects of specimen thickness, the extension of crack growth and characterizing parameter on the crack tip constraint were conducted using the finite element models for the difficult of operating and measuring in the experiment. The results show that there is a significant effect of specimen thickness on the trajectory of the crack tip while there is a small effect of the specimen type on the trajectory of the crack tip; there are significant changes in the direction of the specimen thickness and the direction of crack propagation; the global constraint factor αg equals to the stress triaxiality Am. Conclusions have great theoretical values and guidance for the CTOA test.
Keywords: fracture mechanics; crack tip constraint; Gurson model; crack tip trajectory; CTOA
2014, 40(4): 15-19 收稿日期: 2014-1-7;收到修改稿日期: 2014-3-12
基金项目:
作者简介: 孔令圳(1986-),男,山东滨州市人,博士研究生,研究方向为管道环焊缝断裂分析评价。
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