摘要
采用2A12-T4铝合金漏斗形试件,针对不同拉扭应力幅比,进行了比例加载下多轴高周疲劳寿命试验,研究了不同应力幅比对多轴高周疲劳寿命的影响.针对试验结果,采用3种常用的多轴高周疲劳寿命预测模型,包括等效应力准则、应力不变量准则、临界面准则进行了预测.结果表明:在相同的Von-Mises等效应力下,随着扭转应力幅与拉压应力幅比值的增大,疲劳寿命逐渐升高.等效应力准则的预测结果或过于危险,或过于安全;应力不变量准则的预测结果认为应力幅比的变化对疲劳失效没有影响,与试验结果不符;临界面准则的预测结果优于其他准则.
Fatigue life experiments with funneled-shape specimens were conducted to investigate the effect of stress amplitude on multi-axial high-cycle fatigue failure of 2A12-T4 aluminum alloy under tension-torsion proportional loading.Based on the experiment results,three kinds of life-prediction criteria,which were widely used for multi-axial high-cycle fatigue analysis,were discussed.The results showe that under the same von-Mises equivalent stress,fatigue life raised gradually when the ratio of stress amplitude in tension and torsion increased.Fatigue life of uniaxial tension is the shortest and that of pure torsion is the longest.The forecast results of equivalent stress criteria are either too dangerous,or too conservative.Stress invariant criteria cannot predict the impact of stress-amplitude ratio on multi-axial high-cycle fatigue failure.Critical-plane criteria has better prediction capability than others.
出处
《北京航空航天大学学报》
EI
CAS
CSCD
北大核心
2010年第8期965-968,共4页
Journal of Beijing University of Aeronautics and Astronautics
基金
凡舟基金资助项目(20100501)
关键词
疲劳
多轴高周疲劳
疲劳寿命
比例加载
应力幅
fatigue
multi-axial high-cycle fatigue
fatigue life
proportional loading
stress amplitude