剥蚀对飞机机翼上蒙皮疲劳寿命的影响分析

Study on the Effects of Exfoliation Corrosion on Fatigue Life of Aircraft Upper Wing Skins

摘要:

剥蚀是影响老龄飞机机翼结构完整性的重要因素之一。文中基于材料的初始不连续状态(initial discontinuity state,IDS),建立了评估剥蚀对机翼上蒙皮疲劳寿命影响的模型,然后利用AFGROW计算了在以压应力为主导的等幅载荷谱作用下,机翼蒙皮针对不同腐蚀损伤程度时的疲劳寿命。还研究了多腐蚀损伤对机翼蒙皮疲劳寿命的影响,结果表明,相对于单腐蚀损伤,多腐蚀损伤大大降低结构的疲劳寿命,但其对剥蚀程度不敏感。与试验结果比较表明,该模型预测结果精确,方法可靠。

Abstract:

Exfoliation is one of important factors which affect fatigue life of aging aircraft wings. Based on initial discontinuity state (IDS) of material, a preliminary analytical model was built which was developed to evaluate the effect of exfoliation corrosion on the residual fatigue life of upper wing skins. A life prediction was then carried out using constant amplitude compression dominated loading for various exfoliation corrosion levels by AFGROW, and the prediction agreed reasonably with the available test data. In the last, the effect of multiple-site corrosion damage (MSCD) on fatigue life was also studied, and the result shows that MSCD is to decrease substantially fatigue life compare to that of a single crack. But this trend is not sensitive to exfoliation level.