航空学报 > 1993, Vol. 14 Issue (12): 639-641

复杂载荷情况下平均应力修正方法

谢里阳, 林文强, 徐灏, 王德俊   

  1. 东北大学319信箱 沈阳 110006
  • 收稿日期:1992-04-15 修回日期:1992-08-05 出版日期:1993-12-25 发布日期:1993-12-25

MEAN STRESS AMENDING METHOD FOR FATIGUE UNDER COMPLEX LOADING

Xie Li-yang, Lin Wen-qiang, Xu Hao, Wang De-jun   

  1. Box 319 of Northeastern University of Technology, Shenyang, 110006
  • Received:1992-04-15 Revised:1992-08-05 Online:1993-12-25 Published:1993-12-25

摘要: 对于复杂载荷下的疲劳问题,应该把平均应力效应分为“静态效应”和“动态效应”两个方面。静态效应只影响最终断裂条件,而动态效应影响疲劳过程中的损伤演化规律和强度退化速率。因此,在计算累积损伤时,只需考虑平均应力的动态效应。根据传统的研究结果及对一些试验数据的分析,提出了一个用于复杂载荷损伤分析计算的“损伤当量应力”,以修正平均应力对疲劳损伤的影响。

关键词: 疲劳损伤, 复杂载荷, 平均应力, 动态效应, 静态效应

Abstract: It is proposed that mean stress effect should be divided into two aspects, i.e.static effect and dynamic effect for fatigue under complex loading. The static effect affects only ultimate fracture condition (the critical residual strength), while the dynamic effect affects damage evolution and residual strength degradation rate. So only the dynamic effect needs to be considered in cumulative fatigue damage calculation. Besides, the present paper proposes an amending formula for calculating "equivalent damage stress", with which the effect of mean stress on cumulative fatigue damage and strength degradation under complex loading can be amended.

Key words: fatigue damage, complex loading, mean stress effect, dynamic effect, static effect