Inconel718榫接结构高低周微动疲劳试验研究  

Study on high-low cycle fretting fatigue life of Inconel718 tenon structure

作　　者：杨晓林 慕琴琴[1] 陈永辉[1] 燕群[1] YANG Xiaolin;MU Qinqin;CHEN Yonghui;YAN Qun(National Key Laboratory of Strength and Structural Integrity,Aircraft Strength Research Institute of China,Xi’an 710065,China)

机构地区：[1]中国飞机强度研究所强度与结构完整性全国重点实验室,西安710065

出　　处：《航空工程进展》2024年第5期120-126,共7页Advances in Aeronautical Science and Engineering

基　　金：国家科技重大专项(J2019-Ⅳ-0010-0078);航空发动机及燃气轮机基础科学中心项目(P2022-B-Ⅲ-006-001)。

摘　　要：航空发动机涡轮叶片在实际服役环境中,受到循环往复的高/低周载荷,这是一种典型的高低周微动疲劳工况。涡轮叶片由于微动疲劳频繁引发疲劳断裂问题,严重影响着航空发动机的安全运行。为了研究热端部件材料的高低周微动疲劳问题,设计一种Inconel718榫连接模拟件,对其开展高低周复合微动疲劳试验。共设计3种不同载荷/频率的试验工况,对比不同工况下模拟件的寿命分布情况。结果表明:高周/低周载荷对榫连接结构的微动疲劳寿命有显著影响,随着高周/低周载荷或者频率的增大,涡轮叶片榫接部位微动疲劳寿命均随之降低;试验结果证明榫接结构高低周微动疲劳试验较好地还原了涡轮叶片实际服役情况;通过显示动力学有限元分析,所预测的裂纹萌生位置与试验结果中裂纹萌生位置分散性较小。The turbine blades of aero-engines are subjected to cyclic high-low cycle loads in actual service environ-ments,which is a typical high-low cycle micro motion fatigue condition.The frequent occurrence of fatigue fracture in turbine blades due to fretting fatigue seriously affects the safe operation of aero-engines.In order to study the high-low cycle fretting fatigue problems of hot end component materials,this paper designs an Inconel718 tenon connection simulation component and conducts high-low cycle composite fretting fatigue tests on it.Three different load/frequency experiment conditions were designed to compare the life distribution of the simulated parts under dif-ferent conditions.The results show that high/low cycle load has significant influence on fretting fatigue life.With the increase of high/low cycle load or frequency,the fretting fatigue life of joints decreases.The test results have proven that the high-low cycle fretting fatigue test of the tenon joint structure effectively reproduces the actual ser-vice condition of turbine blades.By displaying the explicit finite element analysis,the predicted crack initiation loca-tion shows less dispersion compared to the experimental results.

关 键 词：INCONEL718 高低周载荷 高低周频率 微动疲劳 疲劳寿命 

分 类 号：V232[航空宇航科学与技术—航空宇航推进理论与工程]