一种镁合金疲劳评估模型的建立及改进  

Creation and Enhancement of A Fatigue Evaluation Model for Magnesium Alloy

作　　者：阎帅 张哲 王悦东 臧兰兰 任嘉名 董祺 YAN Shuai;ZHANG Zhe;WANG Yuedong;ZANG Lanlan;REN Jiaming;DONG Qi(Urban Railway Development Department,CRRC Dalian Co.,Ltd,Dalian 116021,China;School of Locomotive and Rolling Stock Engineering,Dalian Jiaotong University,Dalian 116028,China)

机构地区：[1]中车大连机车车辆有限公司城铁开发部,辽宁大连116021 [2]大连交通大学机车车辆工程学院,辽宁大连116028

出　　处：《大连交通大学学报》2023年第3期27-33,共7页Journal of Dalian Jiaotong University

基　　金：中国中车科技研究开发计划资助项目(2020CKB287)。

摘　　要：为了研究应用于轨道车辆车体结构的镁合金材料疲劳特性,提出了一种新的疲劳寿命预测模型改进方法。首先,将Bootstrap自助法与最小二乘法相结合,对数据样本进行重抽样,并统计分布特征。其次,依托于应用在轨道车辆上的镁合金,进行单周拉伸试验和高周疲劳试验,得到一系列应力水平-疲劳寿命(S-N)试验数据。最后,通过改进前和改进后的最小二乘法对试验数据进行拟合,得到4种不同存活率下的S-N曲线。结果对比发现,通过改进方法得到的疲劳寿命预测模型对试验数据的拟合优度更好,稳定性及准确性更高。In order to study the fatigue characteristics of magnesium alloy material applied to the body struc-ture of rail vehicles,a new method to improve the fatigue life prediction model is proposed.First,the Boot-strap method is combined with the ordinary least square to resampling the data samples and statistics the distri-bution characteristics.Then,a series of test data of stress level-life(S-N)were obtained through single-cy-cle tensile test and high-cycle fatigue test,relying on the magnesium alloy applied to the rail vehicle.Finally,the S-N curves at four different survival rates were obtained by fitting the test data with improved pre-and im-proved ordinary least square.The results show that the fatigue life prediction model obtained by the improved method has better fitting advantage,stability and accuracy.

关 键 词：镁合金 最小二乘法 疲劳评估模型 P-S-N曲线 Bootstrap自助法 

分 类 号：U270.1[机械工程—车辆工程]