摘要
飞机中大量的机械连接结构存在振动疲劳问题,振动疲劳性能评估是结构服役定寿、安全性设计及评定的关键。为了研究典型钛合金连接结构振动疲劳性能,基于TC4钛合金薄板设计不同支撑形状及不同铆钉间距的典型连接结构,搭建振动疲劳试验系统,通过试验对比不同连接结构在窄带随机载荷下的振动疲劳性能;引入应力严重系数与疲劳缺口系数,提出基于随机振动Srms-N曲线的连接结构振动疲劳寿命预计方法。结果表明:在相近振动应力水平下,T形支撑形式的连接结构其振动疲劳性能优于U形支撑形式;在保证连接强度的前提下,适当增大铆钉间距能提升连接结构抗振动疲劳性能;引入应力严重系数与疲劳缺口系数后,连接结构振动疲劳寿命的预计精度大幅提升,预计寿命与试验结果相差在30%以内。
A large number of mechanical connection structures in aircraft face vibration fatigue problems,and the evaluation of vibration fatigue performance is the key to determine the service life,safety design and evaluation of the structure.In order to study the vibration fatigue performance of typical titanium alloy connection structures,the typical connection structures with different support shapes and rivet spacing are designed based on TC4 titanium alloy thin plates,a vibration fatigue test system is built,and the vibration fatigue performance of different connection structures under narrowband random loads is compared through experiments.The method for predicting the vibration fatigue life of connection structures based on random vibration Srms-N curves is proposed by introducing stress severity coefficients and fatigue notch factor.The results show that under similar vibration stress levels,the vibration fatigue performance of the T-shaped support connection structure is better than that of U-shaped support structure;on the premise of ensuring the strength of the connection,increasing the spacing between rivets appropriately can improve the vibration fatigue resistance of the connection structure;after introducing the stress severity factor and fatigue notch factor,the vibration fatigue life of the connection structure is significantly improved,and the difference between the predicted life and the test results is within 30%.
作者
何石
刘小川
刘海涵
李凯翔
白春玉
HE Shi;LIU Xiaochuan;LIU Haihan;LI Kaixiang;BAI Chunyu(National Key Laboratory of Strength and Structural Integrity,Aircraft Strength Research Institute of China,Xi’an 710065,China)
出处
《航空工程进展》
CSCD
2024年第6期235-243,共9页
Advances in Aeronautical Science and Engineering
基金
工信部民机项目(MJZ5-3N22)。
关键词
钛合金
连接结构
振动疲劳
寿命预计
titanium alloy
connection structure
vibration fatigue
life prediction
