摘要
对航空铝合金7050-T7451疲劳试验数据进行统计分析,得出其对数寿命的标准差与均值近似呈线性关系。在此基础上建立了高循环疲劳和低循环疲劳都适用的基于应变的疲劳寿命概率模型,进一步根据对数寿命均值的置信下限和标准差的置信上限给出了置信水平0.95的概率模型,并应用该模型进行了某航天器机械臂的疲劳可靠性分析,得到了其寿命分布及可靠度水平0.9987的臂管寿命。
The linear relationship between the standard deviations and means of lgNf in different strain levels is discovered by the statistical analysis of the HCF and LCF fatigue test data of AL 7050-T7451,and a strain-based probabilistic model of fatigue life is presented,which is suitable for HCF and LCF.Further-more,the probabilistic model with confidence of 0.95 is established based on the interval estimation of the stan-dard deviations and means of lgNf.The fatigue reliabil-ity of a mechanical hand on space shuttle is analyzed by this model,and the distribution of fatigue life and reliable life with reliability of 0.998 7 are obtained.
出处
《航空制造技术》
2008年第21期82-85,89,共5页
Aeronautical Manufacturing Technology
基金
863国家高技术研究发展计划(2006AA04Z405)
关键词
疲劳寿命
应变
概率模型
Fatigue life Strain Probability model
