改进的概率疲劳极限测定方法  

IMPROVED METHODS FOR THE MEASUREMENTS OF PROBABILISTIC FATIGUE LIMITS

作　　者：赵永翔[1] 何朝明[1] 杨冰[1] 

机构地区：[1]西南交通大学牵引动力国家重点实验室,成都610031

出　　处：《机械工程学报》2004年第5期53-57,共5页Journal of Mechanical Engineering

基　　金：全国优秀博士学位论文作者专项资金(200234);国家自然科学基金(50075073);教育部优秀青年教师资助计划项目(2101);铁道部科技研究开发计划项目(2001J016);西南交通大学校基金

摘　　要：提出了利用升降试验法数据测定概率疲劳极限的3种改进方法。揭示了现有常规法存在不能合理反映疲劳极限的随机性和预测误差较大的缺陷。依据可能的3种试验数据形式,改进方法以疲劳极限附近具有“概率Basquin局部S-N关系”为基础,将疲劳极限视为给定疲劳寿命的条件随机变量,其统计特征通过配对试样的随机疲劳寿命来揭示。应用于车辆LZ50车轴钢概率疲劳极限的测定,验证了改进方法的有效性。Three improved methods are proposed for the measurements of probabilistic fatigue limits under the fatigue tests of up-and-down method. It is revealed that the convention- al method for the measurements couldn't reasonably reflect the stochastic feature of the limits, and exists inevitably errors of measurements. The improved methods, by the three possible cases of given test data, are constructed by the so-called 'random localized Basquin S-N relations' in the range of around the limits. The randomness for the limits is represented by the fatigue lives related to the local relations. Availabilities of the improved methods are indicated by the estimations of the probabilistic fatigue limits of LZ50 axle steel for the Chinese railway vehicles.

关 键 词：疲劳极限 概率分析 LZ50钢 

分 类 号：O346.2[理学—固体力学] TB114.3[理学—力学]