航空学报 > 1997, Vol. 18 Issue (2): 153-156

单峰过载下的疲劳裂纹扩展厚度效应研究

高雅丽, 张诗捷, 刘绍伦   

  1. 北京航空材料研究所25室, 北京, 100095
  • 收稿日期:1996-02-15 修回日期:1996-08-05 出版日期:1997-04-25 发布日期:1997-04-25

STUDIES OF EFFECT OF THICKNESS ON FATIGUE CRACK GROWTH UNDER SINGLE-OVERLOADING CONDITIONS

Gao Yali, Zhang Shijie, Liu Shaolun   

  1. Beijing Institute of Aeronautical Materials, Beijing, 100095
  • Received:1996-02-15 Revised:1996-08-05 Online:1997-04-25 Published:1997-04-25

摘要:

进行了国产2024-T 351 铝合金在单峰过载条件下试样厚度对疲劳裂纹扩展性能影响的试验和分析研究。结果表明: 试样厚度对裂纹扩展迟滞有明显的影响; J. B. Chang 模型中的过载截止比不是材料常数, 它还和疲劳裂纹扩展的应力状态、载荷序列及试样厚度等因素有关。厚试样有较大的过载截止比, 用J. B. Chang 模型进行疲劳裂纹扩展寿命预测时应采用相应试样厚度的过载截止比。

关键词: 铝合金, 试样厚度, 疲劳裂纹扩展, 单峰过载

Abstract:

Exper imental and analytical studies of effect of specimen thickness on fat igue cr ackgr owth behavior wer e car r ied out in domestic 2024-T 351 aluminum alloy. Fatigue cr ack growthtests wer e per formed under single- over loading conditions. The r esults showed that specimenthickness has significant effect on crack growth reta rdation, and over load shutoff r atio is not amater ial constant, which is also r ela ted t o the str ess stat e, loading and specimen thickness.Thick specimen has a lar ger overload shutoff r atio, and t he over load shutoff r atios cor respondingt o specimen t hickness should be used to predict t he fat igue cr ack growth life by J. B. Changmodel.

Key words: aluminumalloy, specimen thickness, fatigue crack growth, single-overloading

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