基于载荷加载次序的疲劳寿命预测改进模型  

An Improved Fatigue Life Prediction Model Based on Loading Sequence

作　　者：薛齐文 杜秀云[2] 王生武 XUE Qiwen;DU Xiuyun;WANG Shengwu(School of Civil Engineering,Dalian Jiaotong University,Dalian Liaoning 116028,China;School of Physical and Electronic Technology,Liaoning Normal University,Dalian Liaoning 116029,China)

机构地区：[1]大连交通大学土木工程学院,辽宁大连116028 [2]辽宁师范大学物理与电子技术学院,辽宁大连116029

出　　处：《中国铁道科学》2019年第1期88-93,共6页China Railway Science

基　　金：国家自然科学基金资助项目(10802015);辽宁省自然科学基金联合基金资助项目(2015020119);辽宁省研究生教育教学改革研究项目(2017);辽宁省转型与创新创业教育项目(2017)

摘　　要：针对Corten-Dolan模型中关键参数d难以确定的问题,在Corten-Dolan模型和既有改进模型引入小载荷、损伤程度和应力状态的基础上,进一步考虑相邻2级载荷的先后次序影响,采用增加应力比系数及将载荷加载次序的影响、损伤程度的影响分别作为独立的影响因素2种不同的方法对参数d进行修正,基于此建立2种Corten-Dolan改进模型。根据常用材料(标准45号钢)焊接接头、合金材料(标准16Mn钢)焊接接头以及Q235B钢焊接接头的试验数据,对前述2种改进模型的疲劳寿命预测有效性和可行性进行验证。结果表明:与传统Miner模型和既有Corten-Dolan改进模型对比,无论是在2级载荷作用下还是在多级载荷使用下,2种改进模型在进行焊接材料疲劳寿命预测时均具有较高的预测精度,且因模型的数学表达式较为简单,无需多层迭代计算,便于应用实际工程中焊接结构的疲劳寿命预测。In view of the difficulty in determining the key parameters d in the Corten-Dolan model,based on the introduction of small loads,damage degrees and stress states to the Corten-Dolan model and the existing improved model,the sequential effects of the adjacent two stage load were further considered.Two improved Corten Dolan models were established on the basis of modifying the parameter d by two different methods,namely,increasing stress ratio coefficient as well as considering the effects of loading sequence and damage degree as independent influencing factors respectively.According to the test data of the welded joints of common materials(standard 45 steel),alloy materials(standard 16Mn steel)and Q235B steel,the validity and feasibility of the above two improved models for fatigue life prediction were verified.Results show that,compared with the traditional Miner model and the existing Corten-Dolan improved model,the two improved models have higher prediction accuracy in the fatigue life prediction of welding materials whether under two stage load or multi-stage load.Because the mathematical expressions of the models are relatively simple and need no multi layer iterative calculation,it is convenient to predict the fatigue life of welded structure in practical engineering.

关 键 词：载荷加载次序 Corten-Dolan模型 疲劳寿命 累积损伤 参数修正 焊接材料 

分 类 号：TG453.9[金属学及工艺—焊接]