【摘要】 采用覆型技术,对TC2钛合金焊缝金属表面疲劳短裂纹群体演化行为进行了实验研究,并应用分形理论对实验观测结果进行了分析·结果表明,钛合金焊缝金属表面群体疲劳短裂纹演化行为具有分形特征;随着疲劳进程中循环次数的不断增加,分形维数也随之增大,对应着材料的损伤在不断加剧;分形维数可以作为一个损伤变量,更好地描述材料的疲劳损伤及演化·更多还原

【Abstract】 The grouping behaviour of short fatigue cracks on surface of the weld metal for TC2 titanium alloy was investigated according to the replicating experiment, and the replicas were analyzed on the basis of fractal theory. The results showed that the feature of grouping behaviour of short fatigue crack satisfies fractal equation. The value of fractal dimension increases with the cycle frequency of increasing fatigue, and the value of fractal dimension can be regarded as a parameter to express better the fatigue damage and its evolution process.更多还原