压力容器2024，Vol.41Issue(4)：34-42,9.DOI:10.3969/j.issn.1001-4837.2024.04.005
应力状态对三点弯曲小试样蠕变性能评价的影响
Influence of stress state on the creep property evaluation of three-point bending test
摘要
Abstract
According to the lack of standards for most of small specimen creep test techniques and the problem that changes on the specimen size tend to cause changes on the stress state,which in turn affects the accuracy of creep parameter inversion,this research used finite element method to analyze the stress state of specimens with different cross-sectional width-thickness ratios and its influence on creep properties of three-point bending test based on the constitutive model of beam bending and Norton power law.The results show that when the cross-sectional width-thickness ratio b:2h is less than 1:2,the specimen tends to be in a plane stress state;When the ratio b:2h is larger than 2:1,the specimen tends to be in a plane strain state;When the ratio b:2h is between 1:2 and 2:1,the specimen falls in between the two states.For the load-point steady-state displacement rate,creep stress,conversion coefficient and creep parameter inversion,the influence of plane stress state is significantly greater than that of plane strain state.The comparison with uniaxial creep test data shows that the width-thickness ratio b:2h should be controlled within the range of 1:1 to 2:1,which can improve the accuracy of creep parameter inversion.The results provide basis for the rational application of three-point bending test technique.关键词
三点弯小试样/蠕变/应力状态/有限元Key words
small three-point bending specimen/creep/stress state/finite element分类
机械制造引用本文复制引用
万云杰,郭旭阳,周帼彦,涂善东..应力状态对三点弯曲小试样蠕变性能评价的影响[J].压力容器,2024,41(4):34-42,9.基金项目
国家自然科学基金重点项目(52130511) （52130511）
国家磁约束核聚变能发展研究专项项目(2022YFE03120000) （2022YFE03120000）
