开展航空7B04铝合金试件模拟机场环境的加速点蚀试验,获得点蚀损伤数据,定义点蚀蚀坑表面长度、宽度及蚀坑深度分别由A、B、C三个参量表示,此三个参量之间比例关系可确定典型蚀坑形貌特征.在此基础上,采用ABAQUS软件对一定载荷条件下典型形貌特征蚀坑的应力集中系数Kf进行量化分析.研究表明,随着点蚀周期延长,点蚀形貌逐渐呈表面椭圆、深度适中特点,量化结果为大部分B/A、C/A的值介于1和4之间,其最大值分别很少超过8和10;应力集中系数受点蚀形貌特征影响明显,表面形状一定时,应力集中系数Kf随蚀坑深度增加而增加;蚀坑深度一定时,应力集中系数Kf随蚀坑宽度增加而降低.上述结论可为飞机铝合金结构腐蚀疲劳寿命分析奠定理论基础.%The accelerated pitting corrosion test of 7B04 aluminum alloy specimen was carried out according to the spectrum which simulated airport environment,and the corresponding pitting corrosion damage was obtained and was defined through three parameters A and B and C which respectively denoted the corrosion pit surface length and width and corrosion pit depth. The ratio between three parameters could determine the morphology characteristics of corrosion pits.On this basis the stress concentration factor of typical corrosion pit morphology under certain load conditions was quantitatively analysed.The research shows that the corrosion pits gradually incline to be ellipse in surface and moderate in depth,and most value of B/A and C/A lie in 1 between 4 and few maximum exceeds 4;The stress concentration factor Kfof corrosion pits is obviously affected by the its morpholoy,the value of Kfincreases with corrosion pits depth increasement under certain corrosion pits surface geometry. Also, the value of Kfdecreases with surface width increasement under certain corrosion pits depth. The research conclusion can set theory basis for corrosion fatigue life analysis of aircraft aluminum alloy structure.
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