(西安建筑科技大學(xué) 冶金工程學(xué)院，西安 710055)
摘 要: 在不同的應(yīng)力集中系數(shù)Kt和應(yīng)力比R下，分析缺口(應(yīng)力集中)和平均應(yīng)力對(duì)TC18棒材疲勞強(qiáng)度的影響。結(jié)果表明：TC18棒材的應(yīng)力幅σa隨應(yīng)力集中系數(shù)和應(yīng)力比的增大而減小，但其最大應(yīng)力σmax隨應(yīng)力比的增大而增大。應(yīng)力集中和平均應(yīng)力對(duì)TC18棒材疲勞強(qiáng)度的影響可分別用應(yīng)力集中敏感因子A和平均應(yīng)力敏感因子Am來(lái)衡量。為了進(jìn)一步評(píng)估應(yīng)力集中和平均應(yīng)力對(duì)TC18棒材疲勞強(qiáng)度的綜合影響，建立一種新的模型，并且通過(guò)新模型得到的數(shù)據(jù)和實(shí)驗(yàn)結(jié)果匹配較好。
關(guān)鍵字: TC18合金；疲勞強(qiáng)度；應(yīng)力集中；平均應(yīng)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
