摘要
考虑了高强度铝合金表面局部塑性变形特点，并引入小裂纹尖端屈服应力的渐变规律．分析了裂纹尖端屈服应力的这种变动对裂纹张开应力变动规律的影响．同时它还与Ｔ应力共同作用使得线弹性断裂力学不再适用于预测小裂纹尖端塑性区．据此可以解释小裂纹扩展的规律。
Based on the surface local plastic deformation,the variation of crack tip yielding stress in small crack stages were introduced. Because of the lower level of the crack tip yielding stress corresponding to small crack stage,the opening stress of small crack will change from a lower level to its ordinary value.Besides ,the description of the crack propagation with two parameters (the SIF range and T stress term in the Williams series) can explain the fatigue properties of the small cracks,which shows that the propagation of the small cracks cannot be predicted within the scope of LEFM theory.
出处
《北京航空航天大学学报》
EI
CAS
CSCD
北大核心
1996年第3期274-278,共5页
Journal of Beijing University of Aeronautics and Astronautics
基金
国家自然科学基金
关键词
裂纹
疲劳
塑性变形
裂纹扩展
铝合金
crack
fatigue
plastic deformation
crack propagation
T stress
