摘要
研究了分形裂纹扩展对材料疲劳行为的影响。在实验观测的基础上建立了分形裂纹扩展模型。研究表明．分形裂纹扩展的分维Ｄ是裂纹弯折角θ的函数，分形裂纹扩展在裂纹尖端由于弯折而形成“局部混合模式”和裂纹的分形长度效应均很强地影响疲劳裂纹的有效应力强度与有效裂纹扩展速率。本文的理论分析与一些材料的实验结果取得了很好的一致。
In this paper,the fractal effect of crack propagation path on the fatigue behaviors is studied.Based on experimental observations,a fractal modes is established and the fractal dimension,D,for this model is estimated.D is found to be a function of the crack deflection angle.Thus,the irregularity of a crack propagation path is daseribed by this fractal dimension.Considering both the fractal crack length effect and'local mixed mode'effect at the crack tip due to fractal crack kinking,the effective stress intensity range and the effective crack growth rate are analyzed.They are found to be influenced by the fractal dimension of crack propagation and the microstructure of materials.The predicted effective stress intensity range and crack growth rate are compared with there from experiments for certain materials,good agreements are achieved
出处
《机械强度》
CAS
CSCD
北大核心
1996年第1期1-5,共5页
Journal of Mechanical Strength
基金
国家杰出青年科学基金
国家教委跨世纪优秀人才专项基金
关键词
疲劳
分形裂纹扩展
有效应力强度
fatingue,fractal crack propagation,effective stress intensity crack growth rate
