摘要
针对镁合金焊接结构的疲劳性能问题,用热点应力法对10 mm厚的AZ31B镁合金对接接头和纵向非承载十字接头的疲劳强度进行评定,并用国际焊接学会推荐的方法进行数据处理,做出热点应力S-N曲线并与名义应力S-N曲线进行对比。试验分析表明:试验所采用的两种焊接接头用名义应力法评定时疲劳数据分散性较大,相关系数为0.916,试验疲劳级别分别为FAT35和FAT25;用热点应力法评定时疲劳数据分散性明显减小,相关系数为0.957,比前者提高4.48%,两种焊接接头疲劳强度可以用一条S-N曲线表示,试验疲劳级别为FAT33;这两种评定方法的试验疲劳级别都高于按国际焊接学会推荐的m=3得到的疲劳级别,说明选取m=3进行结构设计具有较高的安全系数。
To study the fatigue properties of magnesium alloy weld structures,the fatigue strength of butt joint and non-load-carrying longitudinal cruciform joint of AZ31B magnesium alloy with 10 mm thickness are evaluated by hot spot stress approach.The test data is statistically treated with the method recommended by International Institute of Welding（IIW）.The hot spot stress S-N curves are obtained and compared with the nominal stress S-N curves.The test analysis shows that the fatigue data of two kinds of joints is dispersed greatly when it is evaluated by nominal stress approach,and its correlation coefficient is 0.916,the test fatigue level are respectively FAT35 and FAT25.In comparison with nominal stress approach,the dispersibility evaluated by hot spot stress is reduced obviously.Correlation coefficient is 0.948,which improves about 4.48 %,thus the fatigue strength can be expressed a single one S-N curve,and fatigue level is FAT33.The test fatigue level of these two evaluation methods is higher than the fatigue level obtained by using 3 recommended by IIW,which indicates there is a higher safety factor in weld structure design if 3 is applied.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2011年第10期52-56,63,共6页
Journal of Mechanical Engineering
基金
国家自然科学基金资助项目(50655148)
关键词
AZ31B镁合金
名义应力法
热点应力法
疲劳评定
AZ31B magnesium alloy Nominal stress approach Hot spot stress approach Fatigue evaluation
作者简介
王文先，男，1963年出生，教授，博士研究生导师。主要从事材料连接及其界面行为、焊接结构强度与断裂性能等方面的研究，发表论文50余篇。E-mail：wwx960@126．com
