摘要
利用三维有限元模拟和动态响应试验对点焊接头疲劳裂纹萌生和扩展特性进行了研究。利用所模拟的裂纹长度和固有频率的关系,定义了点焊疲劳裂纹扩展的三个阶段。根据所定义的裂纹萌生阶段的定义,利用局部应力应变法预测了点焊接头的疲劳裂纹萌生寿命。结果表明,所预测的疲劳萌生寿命与试验结果相吻合。
Fatigue crack characteristics are investigated based on the dynamic response simulation by finite element and the dynamic response experiments for tensile-shear spot-welded specimens. In the different fatigue damage cumulative quantity, the dynamic response frequency is measured during the fatigue damage process. The results show that the natural frequency varies non-linearly with the fatigue damage fraction. On the basis of the relationship between the crack length and the natural frequency, the definition of fatigue crack initiation stage is proposed. Fatigue crack initiation life is predicted by the local stress and strain approach with the proposed fatigue crack initiation stage for tensile-shear spot-welded specimens. The results show that good agreement is achieved with experimental data.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2005年第5期49-53,共5页
Journal of Mechanical Engineering
基金
北京市自然科学基金(3042003)北京市教委科技发展基金资助项目。
关键词
3D有限元
点焊接头
疲劳裂纹萌生与扩展
固有频率
寿命预测
3D Finite element Spot-welded joint Fatigue crack initiation and propagation Natural frequency Life prediction
