小子样条件下镁合金焊接接头疲劳评估方法研究  

Fatigue Evaluation Method of Magnesium Alloy Welded Joints under Small Samples

作　　者：刘波[1] 王悦东 赖泰鸿 高树乾 张雪丽 LIU Bo;WANG Yuedong;LAI Taihong;GAO Shuqian;ZHANG Xueli(Zhan Tianyou College(CRRC College),Dalian Jiaotong University,Dalian 116028,China)

机构地区：[1]大连交通大学詹天佑学院(中车学院),辽宁大连116028

出　　处：《大连交通大学学报》2024年第6期92-98,共7页Journal of Dalian Jiaotong University

基　　金：国铁集团科技研究开发计划项目(2022YJ322)。

摘　　要：以小子样条件下镁合金焊接接头的疲劳试验数据为基础,基于样本信息聚集原理提出分阶段信息聚集方法,与最小二乘法相结合,提出一种小子样条件下镁合金焊接接头疲劳寿命评估模型。首先,利用样本信息聚集原理将数据样本的容量扩大,并统计分布特征;其次,对镁合金焊接接头进行高周疲劳试验,得到小子样条件下的疲劳寿命试验数据;最后,通过改进前和改进后的样本信息聚集方法与最小二乘法结合对试验数据进行拟合并对比。结果表明:分阶段样本信息聚集方法结合最小二乘法得到的p-S-N曲线疲劳寿命评估模型的样本数据具有分散性更小的特征,拟合优度更好,可以确保小子样数据的拟合精度。Based on the fatigue test data of magnesium alloy welded joints under small sample conditions, a staged information aggregation method is proposed based on the principle of sample information aggregation, and a new fatigue life prediction model is proposed combined with the ordinary least square. Firstly, the capacity of the data samples is enlarged by using the principle of sample information aggregation, and its distribution characteristics are counted. Then, relying on magnesium alloys applied to rail vehicles, high-cycle fatigue tests are conducted to obtain a series of stress range-life(S-N) test data. Finally, the S-N curves at different survival rates were obtained by fitting the experiment data through sample information aggregation before and after improvement combined with the ordinary least square. After comparing the results, we found that the fatigue life prediction model obtained by the improved method is a better fit for the test data and has higher stability and accuracy.

关 键 词：镁合金 最小二乘法 小子样 样本信息聚集原理 疲劳评估模型 

分 类 号：TG407[金属学及工艺—焊接]