摘要
剥蚀是影响老龄飞机结构完整性的重要因素之一。本文对LY12CZ铝合金含孔试件进行了预剥蚀疲劳试验,试验结果表明剥蚀使疲劳寿命下降,但其与剥蚀程度并不成正比。运用MSC.Marc中的单元"软化"技术模拟了剥蚀对试件应力分布影响,结果表明最大主应力不但与腐蚀深度有关,还与腐蚀形貌和位置有关。最后基于材料的初始不连续状态(initial discontinuity state,IDS),建立了评估剥蚀对含孔试件疲劳寿命影响的模型。预测值与试验结果比较表明,该模型预测结果精确,方法可靠。
Exfoliation is one of important factors which affect fatigue life of aging aircraft structure. Prior exfoliation corrosion fatigue test of specimens with hole was carried out. The results suggest that the level of exfoliated is not the critical factor that governing the life of specimen. The soft inclusion technique was applied to simulate the effect of exfoliation on maximum principal stresses in the MSC.Marc model. The results show that the level, shape and location of exfoliation all have significant effect on principal stresses. Based on initial discontinuity state （IDS） of material, this paper presents a preliminary analytical model which was developed to evaluate the effect of exfoliation corrosion on the residual fatigue life of specimen. A life prediction was then carried out based on the 3D finite element and soft inclusion, and the prediction agreed reasonably with the test result.
出处
《强度与环境》
2010年第2期49-54,共6页
Structure & Environment Engineering
基金
国家自然科学基金资助项目(50675221)
关键词
剥蚀
疲劳寿命
初始不连续状态
有限元
应力集中
exfoliation corrosion
fatigue life
initial discontinuity state
finite element
stress concentration
