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

作　　者：廖祥雲 王瑞杰[1] 刘国寿[2] 赵平林 常亚光 王钟德 LIAO Xiangyun;WANG Ruijie;LIU Guoshou;ZHAO Pinglin;CHANG Yaguang;WANG Zhongde(Faculty of Mechanical and Electrical Engineering,Kunming University of Science and Technology,Kunming 650500,China;School of Architectural Engineering,Kunming University of Science and Technology,Kunming 650500,China)

机构地区：[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

出　　处：《航空材料学报》2025年第1期44-52,共9页Journal of Aeronautical Materials

基　　金：国家自然科学基金(51065012)。

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。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 

分 类 号：V261.34[航空宇航科学与技术—航空宇航制造工程] TG407[金属学及工艺—焊接]