摘要
针对现有建立寿命设计曲线方法的不足,采用容限法建立寿命设计曲线,对比并分析了各种方法的差异.对于大样本的疲劳试验数据,试验结果表明在不同应力水平材料寿命的分散性不同.为此在近似Owen容限法基础上提出了一种包含应力水平的分散性模型建立设计曲线,使其能够满足材料寿命在高应力分散性较小,低应力分散性较大的特点.根据Ti-6246疲劳试验结果,利用该方法计算得到的设计寿命在疲劳载荷为925MPa时提高了146%,在820MPa时减小了60.2%.从而提高了设计的经济性和可靠性.
Tolerance limit concept was used to construct design curves against the defi- ciencies of the existing methods. Comparative analysis was implemented to evaluate the safe- ty of the design curve. Experimental result shows that fatigue scatter varies with stress lev- els. Based on approximate Owen tolerance limit, an improved design curve has been devel- oped to comply with the feature of fatigue scatter that becomes small in high stress levels and large in low stress levels. According to the fatigue test results of Ti 6246, the fatigue life de- rived from the new method increased by 146% at 925 MPa and decreased by 60.2% at 820 MPa compared with other methods. Reliability and economy can be improved with the new fatigue design curve.
出处
《航空动力学报》
EI
CAS
CSCD
北大核心
2015年第10期2312-2317,共6页
Journal of Aerospace Power
关键词
设计曲线
疲劳分散性
容忍限
置信水平
可靠度
疲劳寿命
design curve
fatigue scatter
tolerance limit
confidence level
reliability
fatigue life
