摘要
利用含内缺口的圆环试件,用实验和计算的方法,研究了两种铝合金在混和应力场下的孔边裂纹萌生特性,并利用扩孔形成的残余应力和变形,探讨对延迟裂纹继续发展产生的作用。扩孔残余应力场的存在使萌生裂纹的循环周次得到提高,对于 型应力场,延迟裂纹萌生的效果非常明显,而对于 型和 型混合应力场,延迟裂纹萌生的效果较弱。
The behavior of fatigue crack initiation from the hole edge of a circular ring specimen containing an internal notch was investigated experimentally and calculatedly for two aluminum alloys. The effects of an expanded hole that forms the residual stress and deformation at the hole edge on the delay of fatigue crack initiation were studied. An obvious increase in the delay of crack initiation was obtained in the case of mode I stress field due to the compressive residual stress produced by the hole expansion process. However in the case of the mixed mode of I + II, the delay was less obvious because of the existence of shear stress.
出处
《航空材料学报》
EI
CAS
CSCD
2003年第4期1-4,共4页
Journal of Aeronautical Materials
基金
国家重点基础研究规划项目(No.G19990650)
国家自然科学基金项目(No.19972030)
关键词
残余应力
铝合金
应力场
疲劳裂纹
航天材料
航空材料
扩孔
Aluminum alloys
Compressive stress
Crack initiation
Finite element method
Shear stress
