(西安建筑科技大学 冶金工程学院，西安 710055)
摘 要: 在不同的应力集中系数Kt和应力比R下，分析缺口(应力集中)和平均应力对TC18棒材疲劳强度的影响。结果表明：TC18棒材的应力幅σa随应力集中系数和应力比的增大而减小，但其最大应力σmax随应力比的增大而增大。应力集中和平均应力对TC18棒材疲劳强度的影响可分别用应力集中敏感因子A和平均应力敏感因子Am来衡量。为了进一步评估应力集中和平均应力对TC18棒材疲劳强度的综合影响，建立一种新的模型，并且通过新模型得到的数据和实验结果匹配较好。
关键字: TC18合金；疲劳强度；应力集中；平均应力
（School of Metallurgical Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China）
Abstract:Under different stress concentration factors Kt and stress ratios R, the effects of notch (stress concentration) and mean stress on fatigue strength of TC18 bars were analyzed. The results show that the stress amplitude σa of TC18 bars decreases with the increase of stress concentration factor and stress ratio, but the maximum stress σmax increases with the increase of stress ratio. TC18 bars have great sensitivity of stress concentration effect and mean stress effect on fatigue properties. And, its effects on fatigue strength can be characterized by stress concentration sensitivity factor A and mean stress sensitivity factor Am, respectively. In order to evaluate the comprehensive effect of stress concentration and mean stress on fatigue strength of TC18 bars, a new model is established, and the data obtained by the new model agree well with the experimental results.
Key words: TC18 alloy; fatigue strength; stress concentration; mean stress
