摘要
根据裂尖疲劳损伤累积导致材料破坏的观点,发展了一个弹塑性疲劳裂纹扩展模型。假设在裂纹前缘HRR场内存在一个高应变区,该区长度X~*等于材料常数D、其塑性变程是Δε~*,由Manson公式求出对应于Δε~*的疲劳破坏循环数N~*,则疲劳裂纹扩展速率就是X~*/N~*。新模型建立了材料低周疲劳特性与弹塑性裂纹扩展规律之间的联系。由模型计算得到的弹塑性裂纹扩展速率与实验结果的比较表明,二者吻合良好。
A model of elastoplastic fatigue crack growth based on cumulative damage analysis near crack tip is developed. It is assumed that at the crack tip there exists a small highly strained area, the width of which X~* is equal to D defined by Hutchinson. Musuva's plane stress solution is used to calculate the plastic strain range in this area. For the known strain range the number of cycles N~* necessary for material failure is obtained from Manson's relation. Then the fatigue crack growth rate is calculated by the ratio X~*/N~*. The results are in good agreement with those from experiments.
出处
《西南交通大学学报》
EI
CSCD
北大核心
1992年第6期12-18,共7页
Journal of Southwest Jiaotong University
关键词
低周疲劳
累积损伤
裂纹扩展
low cycle fatigue
cumulative damage
crack growth
