WNQ570桥梁钢及其对接焊缝疲劳裂纹扩展性能试验研究  

EXPERIMENTAL STUDY ON FATIGUE CRACK BEHAVIOR OF BRIDGE STEEL WNQ570 BASE METAL AND BUTT WELD

作　　者：宗亮[1,2] 施刚[2] 王元清[2] 廖小伟[2] 于兴哲[3] 

机构地区：[1]天津大学建筑工程学院滨海土木工程结构与安全教育部重点实验室,天津300072 [2]清华大学土木工程系土木工程安全与耐久教育部重点实验室,北京100084 [3]清华大学航天航空学院材料力学与固体力学研究所,北京100084

出　　处：《工程力学》2016年第8期45-51,共7页Engineering Mechanics

基　　金：铁道部科技研究开发计划项目(2012G011-E)

摘　　要：对WNQ570桥梁钢及其对接焊缝进行了疲劳裂纹扩展速率和疲劳裂纹扩展门槛值测定试验,采用两种不同数据拟合方法分别得到具有95%保证率的疲劳裂纹扩展参数。结果表明:本批次的WNQ570钢材具有良好的疲劳裂纹扩展性能,其中对接焊缝疲劳裂纹扩展速率高于母材;在应力强度因子幅值处于10 MPa·m^(1/2)~70 MPa·m^(1/2)的常规区间时,基于单试件数据点的处理结果对应的裂纹扩展速率明显高于基于成组数据点的处理结果;WNQ570的疲劳裂纹扩展速率随应力比增加而增加,疲劳裂纹扩展门槛值随应力比增加而降低。An experimental study on fatigue crack growth rate and threshold of WNQ570 base metal and butt weld is performed. Two data processing methods are adopted to derive fatigue crack growth parameters with a 95% confidence level. It turns out that the fatigue crack growth performance of WNQ570 of this batch is excellent, and the fatigue crack growth rate of butt welds is higher than that of the base metal. When the stress intensity is in a common range between 10 MPa · m1/2 and 70 MPa·m1/2, the fatigue crack growth rate based on each specimen＇s data is higher than that based on group method of the data. Furthermore, the fatigue crack growth rate increases and the fatigue crack growth threshold decreases as the stress ratio increases.

关 键 词：WNQ570 桥梁钢 对接焊缝 疲劳裂纹扩展速率 疲劳裂纹扩展门槛值 

分 类 号：U448.36[建筑科学—桥梁与隧道工程] TG405[交通运输工程—道路与铁道工程]