Theoretical and experimental determination of DFR-corrosion-influence-factors
-
摘要: 为使腐蚀环境下民机结构疲劳分析的细节疲劳额定值(DFR)方法具有更广泛适用性,对DFR腐蚀影响系数与腐蚀环境的关系进行了研究,将DFR的腐蚀影响系数分解为地面停放腐蚀影响系数和空中腐蚀疲劳影响系数,建立了地面停放腐蚀影响系数与地面停放腐蚀时间的关系,以及空中复杂综合环境腐蚀疲劳影响系数与单一介质环境腐蚀影响系数的关系.通过试验测定了各种典型情况的DFR腐蚀影响系数,试验结果说明DFR腐蚀影响系数随着地面停放腐蚀时间的增加和环境腐蚀性的增强而降低,腐蚀疲劳的影响较停放腐蚀的影响更严重.分析实例具体说明了腐蚀条件下DFR方法的具体步骤和所需数据,并体现出疲劳分析中计及腐蚀影响的必要性.Abstract: The relationship of detail fatigue rating(DFR)-corrosion-influence-factors and aggressive environments was studied, which makes the DFR method under erosion environments for civil aircraft structures’ fatigue analysis more applicable to different structure details and different service environments. The way wasestablished to decompose DFR-corrosion-influence-factor into ground-corrosion- influence-factor and air-corrosion-fatigue-influence-factor. The relationship between ground-corrosion-influence-factor and corrosion time as well as the relationship of perplexing environment corrosion-fatigue-influence-factor and mono-medium corrosion-fatigue-influence-factors were studied. Experiments for typical influence factors testing were conducted and reported. The results show that DFR-corrosion-influence-factors are decreasing as the increasing of ground-corrosion-time and the aggravating of environments causticity. The influence of corrosion fatigue is much serious than that of ground-corrosion. The example of structure fatigue analysis with DFR method under corrosive environment shows the detail steps and data requirements. The analysis indicates that DFR of a given structure is reduced significantly by corrosion, and the influence must be taken into account properly in fatigue analysis.
-
Key words:
- fatigue /
- corrosion /
- corrosion-fatigue /
- experiment /
- civil aircraft /
- detail fatigue rating
-
[1] 张建宇,鲍蕊,陈勃,等. 腐蚀环境下疲劳分析的DFR方法研究 . 北京航空航天大学学报, 2004, 30(6):547-550 Zhang Jianyu, Bao Rui, Chen Bo, et al. Study on DFR method under corrosive environment for fatigue analysis[J]. Journal of Beijing University of Aeronautics and Astronautics, 2004, 30(6):547-550 (in Chinese) [2] 鲍蕊,张建宇,陈勃,等. 试验测定DFR的升降法方法[J]. 北京航空航天大学学报, 2004, 30(1):47-50 Bao Rui, Zhang Jianyu, Chen Bo, et al. The up and down method for DFR testing[J]. Journal of Beijing University of Aeronautics and Astronautics, 2004, 30(1):47-50 (in Chinese) [3] 鲍蕊. 腐蚀条件下民机结构DFR方法及裂纹扩展分析 . 北京:北京航空航天大学航空科学与工程学院, 2005 Bao Rui. A study of DFR method and crack growth law under corrosion environments for civil aircraft structures . Beijing:School of Aeronautic Science and Technology, Beijing University of Aeronautics and Astronautics, 2005(in Chinese) [4] 刘文 王 廷 ,杨洪源,贺小帆. 腐蚀条件下民机结构疲劳寿命评定方法研究[J]. 北京航空航天大学学报, 2004(8):753-756 Liu Wenting, Yang Hongyuan, He Xiaofan. Evaluation of fatigue lives for civil aircraft structures under corrosive condition[J] Journal of Beijing University of Aeronautics and Astronautics, 2004(8):753-756(in Chinese) [5] 贺小帆.腐蚀条件下飞机结构寿命可靠性关键技术研究 , 北京:北京航空航天大学飞行器设计与应用力学系, 2003 He Xiaofan. Research on life reliability hey techniques for aircraft structures under corrosion condition . Beijing:Dept of Flight Vehicle Design and Applied Mechanics, Beijing University of Aeronautics and Astronautics, 2003(in Chinese) [6] 刘秀晨,安成强. 金属腐蚀学[M]. 北京:国防工业出版社,2002 Liu Xiuchen, An Chengqiang. Metallic corrosion[M]. Beijing:National Defence Industry Press, 2002(in Chinese) [7] 陈群志, 腐蚀环境下飞机结构日历寿命技术体系研究 . 北京:北京航空航天大学, 1999 Chen Qunzhi. Calendar life of aircraft structure under corrosive environments . Beijing:Beijing University of Aeronautics and Astronautics, 1999 (in Chinese) [8] 郑晓玲,李令芳. 民机结构耐久性与损伤容限设计手册(上册)疲劳设计与分析[M]. 北京:航空工业出版社,2003 Zheng Xiaoling, Li Lingfang. Handbook of civil aircraft structures durability and damage tolerance design[M]. Beijing:Aviation Industry Press,2003 (in Chinese) [9] Wanhill R J H, Koolloos M F J. Fatigue and corrosion in aircraft pressure cabin lap splices[J]. International Journal of Fatigue, 2001,23:S337-S347 [10] Du M L, Chiang F P, Kagwade S V. Damage of Al 2024 alloy due to sequential exposure to fatigue, corrosion and fatigue[J]. International Journal of Fatigue, 1998,20(10):743-748 [11] Margery M E. Hoffman P C. Corrosion and fatigue research-structural issues and relevance to naval aviation[J]. International Journal of Fatigue, 2001,23:S1-S10
点击查看大图
计量
- 文章访问数: 3192
- HTML全文浏览量: 93
- PDF下载量: 1123
- 被引次数: 0