航空学报 > 1986, Vol. 7 Issue (6): 636-639

短裂纹疲劳扩展的试验方法

焦良, 倪惠玲   

  1. 西北工业大学
  • 收稿日期:1986-03-08 修回日期:1900-01-01 出版日期:1986-12-25 发布日期:1986-12-25

TEST METHOD OF SHORT CRACK PROPAGATION UNDER FATIGUE LOADS

Jiao Liang, Ni Huiling   

  1. Northwestern Polytechnical University
  • Received:1986-03-08 Revised:1900-01-01 Online:1986-12-25 Published:1986-12-25

摘要:

近十年来,人们发现短裂纹具有一系列不同于普通长裂纹的特异扩展规律,它对耐久性损伤容限分析具有重要的意义。短裂纹扩展率试验是短裂纹研究中一项迫切而重要的,同时也是较为困难的工作。

Abstract:

A double step precracking technique is suggested for gaining an original crack which will be accepted as a genuine short crack. An optimum precracking program under falling amplitude fatigue loadis proposed which can, in combination with the double step precracking technique, reduce the stress intensity range K to below the threshold valve K (defined for long racks in engineering), and can effectively shorten precracking time. A method of locating crack tip on the specimen surface is presented to make identification of the crack tip convenient and accurate.