7075/6061铝合金TIG焊搭接接头疲劳性能评估
Fatigue property evaluation of 7075/6061 aluminum alloy TIG welded overlap joints
廖祥雲 1王瑞杰 1刘国寿 2赵平林 1常亚光 1王钟德1
作者信息
- 1. 昆明理工大学机电工程学院,昆明 650500
- 2. 昆明理工大学建筑工程学院,昆明 650500
- 折叠
摘要
对 7075/6061铝合金TIG角焊缝搭接试件进行恒幅疲劳测试,根据热点应力法与临界距离法细节分别建立有限元应力应变分析模型,在模型中提取最大主应力变化范围进行分析.基于有限元应力应变分析结果并结合IIW推荐的S-N曲线估算不同载荷下焊缝接头的疲劳寿命.结果表明:试件主要在 7075侧焊趾处断裂,而有限元模型中最大应力应变集中部位均位于 7075侧焊趾,两者基本一致.预测寿命与实际寿命对比可知,在低周疲劳范围内热点应力法在进行板厚修正的基础上可较好地预测TIG焊件的疲劳寿命,且预测结果误差均在 2个因子范围内.临界距离法中点法和线法均能对热点应力进行预测,其中点法预测精度更高,线法预测精度稍差.
Abstract
Constant-amplitude fatigue tests were conducted on overlap specimens of 7075/6061 aluminum alloy TIG fillet weldes.Subsequently,detailed finite element models were developed based on both the hot spot stress method and the critical distance method.The range of maximum principal stress variation was from these models as a fatigue evaluation index for further analysis.By combining the results of finite element stress-strain analysis with the S-N curve recommended by the International Institute of Welding(IIW),the fatigue lives of the weld joints under various loadings were estimated.Testing revealed that specimens primarily fractured at the weld toes on the 7075 side.The maximum stress-strain concentration points in the finite element model were located at the weld toe on the 7075 side,aligning closely with the actual fracture locations.By comparing the predicted fatigue lives with the actual test results,it was determined that the hot spot stress method can predict the fatigue life of TIG welds more accurately.After correcting for plate thickness,the prediction errors were within a factor of two in the low-cycle fatigue range.Both the point method and the line method within the critical distance method can predict hot spot stress,but the point method yields more precise results than the line method.
关键词
TIG焊/热点应力法/临界距离法/疲劳寿命/有限元分析Key words
TIG welding/hot spot stress method/critical distance method/fatigue life/finite element analysis引用本文复制引用
出版年
2025
国家科技期刊平台
NSTL
万方数据