( 1. 东北大学机械工程与自动化学院， 沈阳 110004；
2. 沈阳航空工业学院机械工程系， 沈阳 110034；
3. 北京航空材料研究院，北京 100095)
摘 要: 对TC2钛合金焊缝金属疲劳表面短裂纹扩展行为进行了实验研究，表明裂纹的扩展过程是多裂纹系统的演化过程。 基于实验结果， 考虑到短裂纹扩展过程中的合并、 干涉作用等因素， 用应力松弛区模糊化的方法， 建立了仿真模型， 对疲劳短裂纹演化的物理过程进行了数值模拟。将短裂纹演化行为模拟结果与短裂纹扩展复型的实验结果比较， 可以看出两者吻合较好， 表明所建立的准则合理、 实用。
关键字: 钛合金； 焊缝金属； 疲劳短裂纹； 数值仿真
（ 1. College of Mechanical Engineering and Automation,Northeastern University,
Shenyang 110004, China;
2. Mechanical Engineering Department,
Shenyang Institute of Aeronautical Industry, Shenyang 110034, China;
3. Institute of Aeronautical Materials, Beijing 100095, China）
Abstract: The propagation behaviour on surface short fatigue cracks of TC2 titanium alloy-weld was investigated according to the experiment. The results show that the process of crack propagation is a multi-crack system. Based on the experimental results, the simulation model was developed by using the method of the fuzzed relaxation regions. The effects of junction and interaction in the short crack propagation process were taken into account. And the simulation for the process of the short fatigue crack propagation and junction was realized. The results indicate that the method make more accurate to set out the process of the short fatigue crack evolution.
Key words: titanium alloy; weld; short fatigue crack; simulation
