基于夹杂-细晶粒区-鱼眼疲劳失效的超长寿命预测模型

发布时间：2018-01-20 20:39

本文关键词： 金属疲劳夹杂起裂细晶粒区鱼眼寿命预测　出处：《工程科学学报》2017年04期 　论文类型：期刊论文

【摘要】：本文旨在研究夹杂-细晶粒区-鱼眼诱发疲劳失效的超长寿命预测模型.基于Cr-Ni-W合金钢疲劳试验结果,结合局部应力-寿命法和位错-能量法,分别构建了局部裂纹萌生寿命模型(LCIL)和考虑夹杂及细晶粒区影响的裂纹萌生寿命模型(IFCIL),并与Tanaka-Mura模型(T-M)进行了对比分析.其次,分别对细晶粒区内的小裂纹扩展行为和细晶粒区外鱼眼内的长裂纹扩展行为进行建模,最终形成了包含裂纹萌生和扩展在内的全寿命预测模型.结果表明,考虑夹杂及细晶粒区影响的裂纹萌生寿命模型(IFCIL)有较高的预测精度;对应细晶粒区的裂纹萌生寿命几乎等同于全寿命;裂纹扩展寿命仅占据全寿命很小的一部分;预测结果全部处于2倍偏差以内,即全寿命模型可有效地用于夹杂-细晶粒区-鱼眼诱发失效的超长寿命预测.
[Abstract]:The purpose of this paper is to study the super-long life prediction model of inclusion-fine-grained zone and fisheye induced fatigue failure. Based on the fatigue test results of Cr-Ni-W alloy steel, combined with local stress-life method and dislocation-energy method. The local crack initiation life model (LCIL) and the crack initiation life model (IFCIL) considering the influence of inclusions and fine grain regions were constructed respectively. And compared with the Tanaka-Mura model T-M. Secondly, the small crack growth behavior in the fine grain area and the long crack growth behavior in the fishhole outside the fine grain zone were modeled. Finally, the whole life prediction model including crack initiation and propagation is formed. The results show that the crack initiation life model (IFCIL), which takes into account the influence of inclusions and fine grain regions, has high prediction accuracy. The crack initiation life corresponding to the fine grain region is almost equal to the whole life. The crack propagation life only occupies a very small part of the whole life. The prediction results are all within 2 times deviation, that is, the whole life model can be used to predict the super-long life of inclusion-fine grain zone and fish-eye induced failure effectively.
【作者单位】：北京理工大学机械与车辆学院;
【基金】：国家自然科学基金资助项目(51305027)
【分类号】：TG142.15
【正文快照】： 当前在航天、航空、车辆等领域中,机械部件的实际承载周期已远超107,甚至达到109~1011[1-2].同时,发生在这个超长寿命区(107周次)的疲劳失效现象,屡见不鲜.因此,明确超长寿命疲劳失效机理,提出合适的超长寿命预测方法已成为当前疲劳研究领域的一个热点[1].目前,合金钢仍然是

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