高周疲劳载荷环境下直升机动部件的损伤容限分析  

DAMAGE TOLERANCE ANALYSIS OF HELICOPTER DYNAMIC COMPONENTS UNDER HIGH CYCLE FATIGUE LOAD

作　　者：穆志韬[1] 华然[1] 段成美[1] 

机构地区：[1]海军航空工程学院分院,青岛266041

出　　处：《机械强度》2002年第1期113-115,共3页Journal of Mechanical Strength

摘　　要：以某型直升机为例 ,用飞行空测载荷数据编制的实测统计载荷谱 ,对直升机高速旋转的尾桨叶的损伤容限进行分析研究。在高周振动载荷环境中的动部件 ,低于安全疲劳极限 (S∞p)的大量小幅值载荷虽对尾桨叶不造成疲劳损伤 ,但其载荷谱中不同低载截除条件对尾桨叶疲劳裂纹扩展寿命的影响较大。本文建立计算模型时还考虑了海洋腐蚀环境的影响 ,结合试验引进了腐蚀修正系数 (Fi) ,最后以 67%S∞p的低载截除条件计算了尾桨叶的裂纹扩展寿命 ,并提出适合外场使用的尾桨叶安全检查周期及检查要求。Damage tolerance means that defects or even damages are permitted in the structure, however they must be limited to some extent and they will not caused disastrous accident before being detected. Because of the special flight features and service environments of helicopter, most dynamic components of helicopter bear high cycle vibration fatigue. The tail blade, one of the critical dynamic components on a helicopter was taken as an example for the analysis in this paper. Authors discussed the effect on crack propagation life by small amplitude loading under safe fatigue limit ( S ∞p ) in high cycle fatigue load environment. From the analyses and calculation, it is found that the small amplitude load, which is lower than safe fatigue limit, has important effect on crack propagation life. The corrosive environmental effect on the helicopter is also taken into account, and a corrosion factor ( F i ), which is obtained from the test under corresponding corrosion environment, is used to modify the fatigue crack growth rate of the helicopter tail blade. Finally, according to the 67% S ∞p low load truncation condition, crack propagation life, safe service inspection period and technical requirement of the tail blade of the helicopter are determined.

关 键 词：损伤容限 疲劳裂纹 尾桨叶 直升机动部件 高周疲劳载荷 

分 类 号：V215.56[航空宇航科学与技术—航空宇航推进理论与工程] V275.1