样本信息聚集原理与P-S-N曲线拟合方法.pdf

学免免w, xue Lu,cm
第49卷第15期
机槭工程学报
Vo1,49No.15
2013年8月
JOURNAL OF MECHANICAL ENGINEERING
Aug.2013
DOI:10.3901/JMIE.2013.15.096
样本信息聚集原理与P-S-N曲线拟合方法
谢里阳1刘建中
(1.东北大学机械工程与自动化学院沈阳110819
2.中航工业北京航空材料研究院北京1000
摘要:基于不同应力水平下试样疲劳寿命对应的概率分位点的致性,研究小样本疲劳试验数据信息提取原理与P-S-N曲线
试验数据统计处理方法。通过聚集不同应力水平下的寿命试验数据、融合不同应力水平下的寿命分布信息,实现各级应力水
平下寿命分散性信息的集成应用。借助失效迹线和等效寿命概念,以及等效寿命分布与真实寿命分布一致性判据,提出确定
寿命标准差与循环应力水平之间关系的方法。在寿命中值(均值)应カ水平关系已知、寿命标准差一应力水平关系待定的情况
下,基于等效寿命分布与真实寿命分布一“致性的统计检验,应用摄动寻优技术确定疲劳寿命标准差一循环应力水平方程。这
种方法相当于把不同应力水平下的疲劳寿命试验数据转换为任一指定应力下的等效寿命,从而得到等效大样本数据,拟合出
较为精确的P-S-N曲线。试验表明,此方法能在较小样本量(20~30的条件下,获得与传统成组法(40~60个样本)接近的P-SN
曲线,且容易应用。
关键词:P-S-N曲线小样本样本集聚信息融合等效寿命
中图分类号:TH114
Principle of Sample Polymerization and Method of P-S-N Curve Fitting
XIE Liyang LIU Ji
lannon
g
1. College of Mechanical Engineering and Automation, Northeastern University, Shenyang 110819
2. Beijing Institute of Aeronautical Materials, Aviation Industry Corporation of China, Beijing 100095)
Abstract: In sense of probability percentiles, there exists a corespondence between specimen fatigues lives associated with different
cyclic stress levels. Based on such a correspondence, the principle to fit P-S-N curve with small sample test data is investigated,
which related with information fusion techniques, and the method to establish P-S-N equation. By polymerizing fatigue life test data
under different cyclic sess eels and ine rating the ife dis r ution information, small sample experiment data can be efficient
applied to acquire the necessary information to estimate the parameters of the probability distributions of fatigue lives associated with
any stress levels. According to the relationship between life distribution and cyclic stress level, fatigue life test data at different stress
levels can be equivalently converted to an arbitrarily specified baseline stress level, and the distribution of the equivalent lives
dentical with that of the est data at the basel s level if e relationship is correct. With the mean life-stress level relationship
fitted by small sample test data, the correct relationship between life standard deviation and stress level can be found by statistical
test oriented perturbation technique. Test resul s illustrate that the P-S-N curves fitted by this method with 20-30 specimens are very
close to those obtained by fitted by conventional method with 40-60 specimens
Key words: P-S-N curve Small size sample Sample congregation Information fusion Equivalent life
和疲劳研究者的关注们。由于疲劳试验耗时长、成
0前言
本高,一般情况下很少能得到满足传统统计方法要
求的大样本数据。现有的基于小样本的疲劳寿命统
长期以来,P-S-N曲线(指定存活率的循环应计推断方法中,一类是借助先验信息的 Bayes统计
力疲劳寿命曲线,简称概率疲劳寿命曲线,或概率方法;另一类是通过改进大样本统计方法,使之
S-N曲线)测试与数据拟合方法一直得到统计学者尽可能适用于小样本问题。傅惠民等凹在假设疲劳
寿命服从对数正态分布的前提下,采用异方差回归
国家自然科学基金61702)和高等学校博士学科点专项科研基金分析技术对疲劳试验数据进行整体分析;昌箴等
(20110421300)资助项目。20130207收到初稿,20130628收到修改稿