一种阶梯块谱下的疲劳累积损伤模型  

A MODEL OF FATIGUE CUMULATIVE DAMAGE UNDER STEP BLOCKS SPECTRUM

作　　者：张禄[1,2] 刘宏利 任春晓 ZHANG Lu;LIU HongLi;REN ChunXiao(Research Institute of Highway Ministry of Transport,Beijing 100088,China;Key Laboratory of Operation Safety Technology on Transport Vehicles,Beijing 100088,China)

机构地区：[1]交通运输部公路科学研究院,北京100088 [2]运输车辆运行安全技术交通运输行业重点实验室,北京100088

出　　处：《机械强度》2024年第5期1228-1235,共8页Journal of Mechanical Strength

基　　金：中央级公益性科研院所基本科研业务费专项资金(2022-9027)资助。

摘　　要：针对阶梯块谱下的材料疲劳寿命预测问题,尤其是已有相关非线性模型的计算参数依赖大量试验数据或较难选取合适的基准值,导致在实际工程中应用有一定局限性。提出了一种新的基于相邻载荷的作用系数α_(i)=(S_(i+1)/S_(i))1/b lg K,该系数中两个参数b、K来自材料疲劳寿命关系式S=KN^(-b)。结合前人的二级、三级、四级应力加载试验结果,分别计算并对比了与多种疲劳损伤模型的结果。结果表明,新模型在疲劳寿命/损伤的预测结果优于Miner模型、Manson模型、Subramanyan模型及Hashin模型,可更为准确地预测阶梯块谱下的疲劳寿命/损伤。In view of the materials fatigue life prediction problem under step blocks specturm,especially the calculation parameters of the existing nonlinear models depend on a large number of test data or it is difficult to select a suitable reference value,which leads to the limitation in practical engineering application.A new effect coefficient α_(i)=(S_(i+1)/S_(i))1/b lg K based on adjacent load was proposed,in which the two parameters b,K were derived from the fatigue life relation S=KN^(-b).The fatigue damage models and the results which combined with the previous experimental results of two-,three-and four-stage loading were calculated and compared.The results show that the new model has better fatigue life/damage predicted results than Miner model,Manson model,Subramanyan model and Hashin model,which can be predicted more accurately in fatigue life/damage under step blocks spectrum.

关 键 词：阶梯块谱 疲劳损伤 疲劳寿命 多级应力 作用系数 

分 类 号：TH142.2[一般工业技术—材料科学与工程]