Generality analysis of the pre-corrosion influence on the fatigue life for aircraft structure
-
摘要: 为研究载荷谱、恒幅应力水平及裂纹尺寸对疲劳寿命预腐蚀影响系数C(T)的影响,建立了基于疲劳寿命服从威布尔分布的C(T)对比法.地面停放预腐蚀对结构疲劳寿命的影响规律可以用C-T曲线表示,当预腐蚀疲劳寿命位于长寿命段,常假定其服从威布尔分布,C(T)为预腐蚀后和未腐蚀结构特征寿命的比值.取预腐蚀疲劳寿命分布函数的形状参数为材料常数,采用极大似然方法估计特征寿命,得到其分布特性,从而建立了C(T)估计量的分布特性,构造了不同环境下的C(T)统计对比法,用于C-T曲线通用性分析. 试验数据分析表明,当取疲劳寿命服从威布尔分布时,C-T曲线与载荷谱、应力水平及裂纹尺寸基本无关.Abstract: To analyze the influence of the different spectra loading, constant amplitude loading and crack size on the pre-corrosion influence factor (C(T)),the C(T) test assuming the fatigue life following the two-parameter Weibull distribution was proposed. The C(T) shows the pre-corrosion influence on aircraft structural life under different ground parking time is the ratio of pre-corrosion characteristic life to un-corrosion characteristic life when the pre-corrosion fatigue life located in the long life range. Assuming the slope of the Weibull distribution is material constant, and the unbiased characteristic life which was estimated with the maximum likehood estimation(MLE), the probability density function of the estimator was determined. The distribution function of the statistic C(T) was obtained, the C(T) contrast approach was proposed, and used to test the hypothesis that the C-T curve is general between different spectra loading, constant amplitude loading and crack size, the fatigue testing data shows that the C-T curve is weak-correlation with these influence factors.
-
Key words:
- corrosion /
- fatigue /
- life /
- Weibull distribution /
- maximum likehood estimation /
- pre-corrosion /
- aircraft structures
-
[1] 蒋祖国. 飞机结构腐蚀疲劳[M]. 北京:航空工业出版社,1994 Jiang Zuguo. Corrosion fatigue for aircraft structures[M]. Beijing:Aviation Industry Press,1994(in Chinese) [2] Simpson D L, Brooks C L. Tailoring the structural integrity process to meet the challenges of aging aircraft[J]. International Journal of Fatigue, 1999,(21):S1~S14 [3] Wanhill R J H, Luccia J J De. An AGARD-coordinated corrosion fatigue cooperative testing programme(CFCTP). AD-A113731, AGARD-R-695, 1982 [4] Wanhill R J H, Luccia J J De, Russo M T. The fatigue in aircraft corrosion testing(FACT) programme. AD-A208359H, AGARD-R-713, 1989 [5] 刘文, 李玉海, 贾国荣. 腐蚀条件下飞机结构使用寿命评定与监控方法研究[J]. 北京航空航天大学学报,1996,22(3):259~263 Liu Wenting, Li Yuhai, Jia Guorong. Evaluation and supervision of service life for aircraft structures under corrosive condition[J]. Journal of Beijing University of Aeronautics and Astronautics, 1996,22(3):259~263(in Chinese) [6] 贺小帆,刘文,向锦武. C-T曲线通用性分析和试验研究[J]. 航空学报,2005,26(2):184~189 He Xiaofan,Liu Wenting,Xiang Jinwu. Analysis and testing on the generality of C-T curve[J]. Acta Aeronautica et Astronautica Sinica, 2005,26(2):184~189(in Chinese) [7] 李玉海. 腐蚀条件下飞机结构寿命体系评定技术研究. 北京:北京航空航天大学飞行器设计与应用力学系, 2001 Li Yuhai. Research on evaluation technique for life system of aircraft structures under corrosive condition. Beijing:Dept of Flight Vehicle Design and Applied Mechanics,Beijing University of Aeronautics and Astronautics, 2001(in Chinese) [8] 王斌团. 结构疲劳日历寿命及其概率研究. 西安:西北工业大学飞行器设计系,2000 Wang Bintuan. Structural fatigue calendar life and its probability. Xi’an:Dept of Flight Vehicle Design, Northwestern Polytechnical University,2000(in Chinese) [9] Whittaker I C, Besuner P M. A reliability analysis approach to fatigue life of aircraft structures. AD 853263, 1969 [10] Whittaker I C. Development of titanium and steel fatigue variability model for application of reliability analysis approach to aircrafts structures. AD-758219, 1972 [11] 茆诗松,王玲玲. 可靠性统计[M]. 上海:华东师范大学出版社,1984 Mao Shisong, Wang Lingling. Reliability statistics[M]. Shanghai:East China University of Science and Technology Press, 1984(in Chinese) [12] 吴学仁. 飞机结构金属材料力学性能手册(第1卷)[M]. 北京:航空工业出版社,1996 Wu Xueren. Handbook of mechanical properties of aircraft structual metals(vol.1)[M]. Beijing :Aviation Industry Press,1996(in Chinese) [13] 胡仁伟. 腐蚀条件下飞机结构耐久性与可靠性. 北京:北京航空航天大学飞行器设计与应用力学系,1998 Hu Renwei. Durability and reliability of aircraft structure under corrosive condition. Beijing:Dept of Flight Vechile Design and Applied Mechanics, Beijing University of Aeronautics and Astronautics, 1998(in Chinese)
点击查看大图
计量
- 文章访问数: 3771
- HTML全文浏览量: 208
- PDF下载量: 653
- 被引次数: 0