近门槛区疲劳裂纹扩展特性

Characteristics of Fatigue Crack Propagation in the Near-threshold Region

本文综述了近年来对近门槛区疲劳裂纹扩展特性的研究,尤其是对短裂纹扩展特性的研究,包括短裂纹的奇异现象。文中强调了裂纹闭合现象对长、短疲劳裂纹扩展的影响,分析了几种闭合机制,对目前各种测量闭合效应的试验方法予以了详细的归纳和评述,指出了在目前的试验条件下,应变片法是一种较理想的方法。最后,文中指出了近门槛区疲劳裂纹扩展研究中一些值得注意的现象和问题。

The results of recent research of the propagstion of fatigue crack in the near-threshiold region is summarized in this paper, especially of the short fatigue crack, including the intresting phenomenon of the short fatigue anomaly. The influence of crack closure on the propagation of long and short fatigue crack is emphasized, several mechanisms of crack closure are analysed, and the experimental methods of crack closure measuring are summarized and commented. In this paper, it is pointed out that strain gauge is a comparatively ideal method for the measure of crack closure udner the present experimental condition. At last some phenomena and problems which are worthy of futher study are showed.