基于聚类分析和支持向量机的非等间隔应力谱编制方法  

UNEQUAL INTERVAL STRESS SPECTRUM COMPILATION METHOD BASED ON CLUSTER ANALYSIS AND SUPPORT VECTOR MACHINE

作　　者：薛海[1] 杜文[1] 尹怀彦 胡李军 XUE Hai;DU Wen;YIN Huai-yan;HU Li-jun(School of Mechatronic Engineering,Lanzhou Jiaotong University,Lanzhou,Gansu 730070,China)

机构地区：[1]兰州交通大学机电工程学院,甘肃兰州730070

出　　处：《工程力学》2023年第11期236-243,共8页Engineering Mechanics

基　　金：甘肃省科技计划项目(20JR5RA412);北京交通大学轨道车辆结构可靠性与运用检测技术教育部工程研究中心开放课题项目(219008);兰州交通大学-天津大学联合创新基金项目(2020058);兰州交通大学天佑创新团队项目(TY202006)。

摘　　要：为保证根据实测应力-时间历程数据编制的应力谱最大程度反映载荷实际作用特性,提出了一种基于疲劳损伤的非等间隔应力谱编制方法。通过引入非等间隔自适应比值系数,根据损伤等效原则,建立应力谱分级数与疲劳损伤关系数学模型;考虑每个应力循环的属性特征,采用聚类分析对所有应力循环进行分类,结合支持向量机多分类进行判别,得到不同分级数下的准确率和预测图;综合考虑数学模型得到的损伤相对误差和支持向量机分类准确率,选取应力谱最佳分级数,编制了相应的非等间隔应力谱,并与目前常用的等间隔和非等间隔8级谱进行比较。分析结果表明:基于损伤等效原则,采用聚类分析和支持向量机进行应力谱分级,不仅考虑了所有应力循环的整体特征,很大程度保留了应力的局部信息和属性,且根据疲劳累积损伤理论得到的损伤与实际损伤结果差异明显降低,从而更能准确反映实测数据的应力特性和疲劳效应,可为其他实测载荷-时间历程数据进行非等间隔分级和载荷谱编制提供参考。A method of unequal interval stress spectrum compilation based on fatigue damage was proposed to ensure the stress spectrum compilation from the measured stress-time history to reflect the actual effect characteristics of the load.According to the damage equivalence principle,a mathematical model of the relationship between the stress spectrum classification numbers and fatigue damage were established by adding unequal interval adaptive ratio coefficients.Considering the attribute characteristics of each stress cycle,cluster analysis was used to classify all stress cycles,while the classification accuracy and prediction map under different classification numbers were obtained based on the support vector machine multi-classification.Considering the relative error of damage obtained from the mathematical model and the classification accuracy of support vector machine,the corresponding unequal interval stress spectrum were compiled by means of the optimal number of stress spectrum,which was compared with the equal interval spectrum and unequal interval spectrum of 8 levels.The results show that the stress spectrum of classification based on the damage equivalent principle,cluster analysis and support vector machine considers the overall characteristics of all stress cycle and the local information and properties of the stress,and the results of the fatigue cumulative damage theory are significantly lower than the actual damage,so that the measured data of stress characteristic and the effects of fatigue are accurately reflected.This method can be used for other measured load-time history to unequal interval classification and load spectrum compilation.

关 键 词：应力谱 疲劳损伤 非等间隔 聚类分析 支持向量机 

分 类 号：TH114[机械工程—机械设计及理论]