摘要
对循环加卸载阶段仅发生弹性应力循环的TA12钛合金双边缺口试样在不同蠕变疲劳载荷下的应力-应变进行了有限元分析,采用时间-循环分数法对不同载荷条件下的蠕变疲劳寿命进行了估算,并对相应条件下的疲劳损伤和蠕变损伤进行了分析。结果表明:蠕变损伤和疲劳损伤对缺口试样蠕变疲劳损伤的贡献度与峰值载荷大小以及峰值载荷保载时间有关;当峰值载荷较小、缺口试样完全处于弹性状态时,蠕变损伤对蠕变疲劳寿命的影响占绝对比例;随着峰值载荷的增大,保载时间相同时,疲劳损伤的影响程度逐渐增大,当保载达到一定时间后,蠕变损伤的影响会超过疲劳损伤的影响。
Stress-strain under different creep-fatigue loads of double edge notched sample of TA12 titanium alloy with only elastic response at cyclic loading and unloading process was analyzed by finite element method. The creep fatigue life under different loads conditions were estimated by time-cyclic fraction method, and the fatigue damage and creep damage under correspondant cond itions were analyzed. The results show that the contribution of creep damage and fatigue damage to creep fatigue damage of notched sample depended on the amplitude of the peak loads and the holding time of peak load. When the peak load was low and the notched sample was in elastic state, the creep damage had a considerable effect to creep-fatigue life. When the holding time was same, the fatigue damage increased gradually with the increase of peak loading and when the holding time reached a period of time, the effect of creep damage would exceed that of fatigue damage.
出处
《机械工程材料》
CAS
CSCD
北大核心
2013年第3期90-94,共5页
Materials For Mechanical Engineering
基金
国防基础科研项目资助(B2520110003)
