Bayesian Estimation and Hierarchical Bayesian Estimation of Zero-failure Data

The zero_failure data research is a new field in the recent years, but it is required urgently in practical projects, so the work has more theory and practical values. In this paper, for zero_failure data (t i,n i) at moment t i , if the prior distribution of the failure probability p i=p{T【t i} is quasi_exponential distribution, the author gives the p i Bayesian estimation and hierarchical Bayesian estimation and the reliability under zero_failure date condition is also obtained.

100Cr6轴承钢的超高周疲劳性能研究

采用旋转弯曲疲劳、SEM+EDS、面扫描等方法,研究了试验用100Cr6轴承钢的高周及超高周疲劳性能,以及传统疲劳极限附近的失效概率分布,并统计了夹杂物的成分、尺寸等信息。结果表明试验钢100Cr6的传统疲劳极限为967 MPa,在其之下的960 MPa应力幅值条件下,部分试样通过10^7循环周次后仍出现疲劳断裂失效,非无限寿命。在传统疲劳极限附近,相比于正态分布,疲劳寿命数据更符合二参数威布尔分布。相比于金相检验和面扫描,疲劳+EDS方法更能发现尺寸较大且为刚性的D类和Ds类夹杂物。