摘要
针对结构中出现的表面裂纹诱发断裂现象,利用断裂力学理论中裂纹尖端应力强度因子与裂纹扩展能量释放率的关系,依据裂纹扩展时裂纹前沿各点的有效能量释放率相等,在考虑裂纹闭合效应的基础上提出一种表面裂纹扩展形状演化计算方法。采用提出的方法计算了T型焊接结构焊趾位置表面裂纹在拉伸疲劳载荷作用下的表面裂纹形状参数函数关系,模拟出表面裂纹疲劳扩展时的形状演化过程。进行了T型焊接试件的表面裂纹扩展有限元模拟和试验,结果与理论计算结果基本一致,验证了基于能量释放率的结构表面裂纹疲劳扩展形状演化计算方法的有效性。
Aiming at the phenomenon of fracture caused by surface crack propagation in structures,by applying the relation between crack-tip stress intensity factor and energy release rate,according to the equal effective energy release rate of every point on the front of surface crack,a calculation method for aspect ratio variation of surface crack growth is proposed.The functional relationship between shape parameters of surface crack in T-joint under tensile fatigue load is calculated by the method proposed in this paper,and the surface crack propagation shape variation is simulated by the calculation results.Surface crack growth experiments and finite element analysis in welding T-joint are proceeded and the results are compared with calculated results,results are basically identical with calculation results,it is effective for the surface crack shape calculation method proposed in this paper to predict the aspect ratio variation of surface crack.
作者
王兴路
贺利乐
WANG Xing-lu;HE Li-le(School of Vehicle Engineering,Xi’an Aeronautical University,Shaanxi Xi’an710077,China;School of Mechanical and Electrical Engineering,Xi’an University of Architecture and Technology,Shaanxi Xi’an710055,China)
出处
《机械设计与制造》
北大核心
2019年第11期36-38,43,共4页
Machinery Design & Manufacture
基金
陕西省自然科学基础研究面上资助项目(2016JM5067)
关键词
表面裂纹
能量释放率
疲劳扩展
形状演化
T型焊接
Surface Crack
Energy Release Rate
Fatigue Propagation
Aspect Ratio Variation
Welding T-Joint
