压力容器2016，Vol.33Issue(2)：1-9,9.DOI:10.3969/j.issn.1001-4837.2016.02.001
基于疲劳寿命的共面多裂纹合并准则研究
Combination Rules for Multiple Coplanar Cracks Based on Fatigue Life
摘要
Abstract
The remnant fatigue lives of finite thickness plates containing a twin of semi-elliptical surface cracks under cyclic loadings are predicted by using finite element simulation technique in order to assess the conservatism of coalescence criteria in the existing structural integrity assessment standards.Twenty-two groups of crack configurations and two different material properties(304 stainless steel and 16MnR steel) are used in the analysis.The conservative degrees of three existing crack coalescence criteria and one type of combination rule presented by authors are discussed.Compared with the remnant lives ob-tained by the method considering interaction,the results show that the conservative degrees of the existing combination rules are highly dependent on the relative size of crack to wall thickness.Combination rules suggested by BS 7910 and ASME may lead to non-conservative results when initial crack depth is large.In addition,the rules suggested by A16,API 579-1 and GB/T 19624—2004 are over conservative.The paper proposes a new combination rule i.e.the minimum distance between cracks being equal to the average crack depth.By conducting sensitivity analysis of parameters in the formula for correlating crack growth rates,it is also found that the conservative degree of the combination rule is significantly dependent on the exponent n in Paris law but is marginally affected by the coefficient C.关键词
寿命预测/裂纹合并准则/有限元分析/疲劳Key words
life prediction/crack coalescence criterion/finite element analysis/fatigue分类
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占勇,温建锋,涂善东,轩福贞..基于疲劳寿命的共面多裂纹合并准则研究[J].压力容器,2016,33(2):1-9,9.基金项目
国家自然科学基金资助项目(51505149,11472105) （51505149,11472105）
中国博士后科学基金资助项目(2015M581543) （2015M581543）
上海市扬帆计划资助项目(15YF1402900) （15YF1402900）
