7A04铝合金高周疲劳性能研究  

Study on high-cycle fatigue performance of 7A04 aluminum alloy

作　　者：宗亮[1,2] 刘衡 陈颖 王中兴 ZONG Liang;LIU Heng;CHEN Ying;WANG Zhongxing(Key Laboratory of Coast Civil Structures Safety of Ministry of Education,Tianjin University,Tianjin 300350,China;School of Civil Engineering,Tianjin University,Tianjin 300350,China)

机构地区：[1]天津大学滨海土木工程结构与安全教育部重点实验室,天津300350 [2]天津大学建筑工程学院,天津300350

出　　处：《建筑结构学报》2023年第8期225-233,共9页Journal of Building Structures

基　　金：国家自然科学基金项目(52278200)。

摘　　要：为研究建筑用7A04超高强铝合金的高周疲劳性能,通过标准单调拉伸试验得到其基本力学性能,并开展了29个试件的高周疲劳性能试验研究。结合试验结果,对7A04铝合金在应力比为0.1下的疲劳S-N曲线进行拟合,对其疲劳断口形貌展开观察,并对基于连续损伤力学的高周疲劳损伤演化模型参数进行标定。结果表明:7A04铝合金高周疲劳断口包括疲劳源区、裂纹扩展区、瞬断区三个典型区域;建立了置信度50%和95%的S-N拟合曲线可较好地描述7A04铝合金疲劳性能;拟合得到了其置信度95%、失效概率5%下的下极限曲线。其疲劳强度高于6061、6005两种典型建筑用铝合金而低于同强度钢材Q460,符合规范中对7XXX系铝合金疲劳性能的要求。To study the high-cycle fatigue performance of 7A04 ultra-high strength aluminum alloy used in construction,basic mechanical properties were obtained by monotonic tensile tests,and high-cycle fatigue tests of 29 coupons were carried out.The fatigue S-N curve under the stress ratio of 0.1 was fitted based on the test results,and the fatigue fracture morphology was observed.Following this,parameters of the high-cycle fatigue damage evolution model based on the continuum damage mechanism were fitted.The results show that the fracture morphology of 7A04 aluminium alloy includes three typical regions,i.e.,crack initiation region,crack propaagation region and final rupture region,the S-N curves with confidence of 50%and 95%have been established and can be used to evaluate its fatigue performance.The fatigue strength of 7A04 aluminum alloy is higher than two typical aluminum alloys 6061 and 6005 used in construction,but lower than Q460 steel,and the fatigue properties of 7A04 aluminum alloy can meet the fatigue requirements of the standards.

关 键 词：超高强铝合金 拉伸试验 高周疲劳性能 疲劳S-N曲线 损伤演化 

分 类 号：TU395[建筑科学—结构工程]