摘要
金属材料裂纹形核不仅受到宏观应力的影响,还受到材料的显微组织、外部环境等因素的影响,不同情况下的裂纹形核条件不一样,形核机理也有所区别,同时裂纹形核历程存在一定的随机分布.通过对疲劳形核的微观机理及疲劳形核的部位方面进行研究,得出当前对裂纹形核机理认识尚不精确,对其预测尚无可行的判据依据,对裂纹形核部位局限于事后分析的结论;对裂纹形核缺乏定性的理论依据,目前仍然无较为成熟的理论来定量表述内外参数和裂纹形核速率的关系.提出发展成功的裂纹形核模型进行统计和数值模拟也是裂纹形核的一个重要研究方向.
Metal materials fatigue crack nucleation is affected by macro stress,micro structure,environment and other factors,the crack nucleation is not the same under various conditions,the nucleation mechanism is also different,and the nucleation mechanism is a certain random distribution. Through the research of the micro mechanism and nucleation site of the fatigue,it points out that the understanding of the crack nucleation mechanism is not exact,the predictions are not based on reliable proof,the crack nucleation site is confined to the posthoc analysis,the prediction of crack nucleation is lack of the quantitative theory,there is no mature theory to quantitatively describe the relationship between the crack nucleation rate and the internal and external parameters. The correct statistics and numerical simulation of the crack nucleation is an important direction of the crack nucleation research in the future.
出处
《兰州工业学院学报》
2016年第4期75-81,共7页
Journal of Lanzhou Institute of Technology
关键词
金属疲劳
裂纹
形核
微观机理
metal fatigue
crack
nucleation
microscopic mechanism
