摘要
为有效预测压力容器对接焊缝焊趾应力集中系数(stress concentration factor,SCF),以双V型对接焊缝(geometrically symmetric butt joint,BJ-S)和带垫板的对接焊缝(butt joint with backing plate,BJ-BP)为研究对象,通过建立有限元模型,对每组200个、共10组以上的不同影响参数组合下的对接焊缝焊趾有限元SCF数据进行回归分析。回归分析中考察了8种不同几何参数以及名义应力对SCF的影响,对BJ-S已有的SCF公式进行修正,提高了不同名义应力下SCF预测公式的准确性;并在此基础上,提出了BJ-BP焊趾的SCF预测公式。结果表明:基于已有角变形的BJ-S公式,对名义应力修正之后,拟合数据和验证数据显示R^(2)由修正前的0.8538提升到0.98以上,且预测公式结果和有限元结果的误差在11%以内。对于BJ-BP焊趾处SCF,将提出的BJ-S的SCF公式应用于BJ-BP时,R^(2)为0.9144,效果不佳。BJ-S公式计算值和BJ-BP有限元结果具有线性关系,通过引入减小率常数进行修正,所得的BJ-BP总SCF公式的R^(2)在0.98以上,且误差小于8.5%,提高了SCF预测的精度,可为不同名义应力水平下的疲劳强度评估提供支撑。
In order to effectively predict the stress concentration factor(SCF)at weld toe of pressure vessel butt welds,a study for SCF prediction formula is conducted using geometrically symmetric butt Joint(BJ-S)and butt joint with backing plate(BJ-BP)as the study objects.Finite element models for each group of 200 butt welds with combination of different parameters are built,and more than 10 groups of finite element SCF are analyzed by regression.In regression analysis,effects of 8 different geometry parameters and nominal stress on SCF are examined,and the existing SCF formulas of BJ-S are modified to improve the accuracy of SCF prediction formulas under different nominal stresses;On this basis,a SCF prediction formula for BJ-BP weld toe was proposed.The results show that:through modifying formula for nominal stress based on the existing BJ-S formula with angular deformation,the fitting data and validation data show that R^(2) of formula increases from 0.8538 before modification to over 0.98,and the errors between the prediction formula results and the finite element results are within 11%.For SCFs at weld toe of BJ-BP,when the proposed SCF formula of BJ-S is applied to BJ-BP,the R^(2) is 0.9144,which has a poor effect for SCF prediction.The results by BJ-S formula have a linear relationship with the finite element results of BJ-BP.By introducing a reduction rate constant for modification,the R^(2) of the total SCF formula of BJ-BP is above 0.98,and the errors are less than 8.5%.This study improves the accuracy of SCF prediction and provides support for fatigue strength assessment at different nominal stress levels.
作者
李博
堤成一郎
宋学伟
柏源
韦飞
郑贵荣
张玉华
顾文浩
钟潇潇
LI Bo;TSUTSUMI Seiichiro;SONG Xuewei;BAI Yuan;WEI Fei;ZHENG Guirong;ZHANG Yuhua;GU Wenhao;ZHONG Xiaoxiao(Guodian Environmental Protection Research Institute Co.,Ltd.,Nanjing 210031,China;Osaka University,Graduate School of Engineering,Suita 565-0871,Japan;China Energy Zhejiang Ninghai Power Co.,Ltd.,Ningbo 315612,China)
出处
《电力科技与环保》
2023年第3期256-261,共6页
Electric Power Technology and Environmental Protection
基金
国家能源科学技术研究院有限公司科技项目“基于电吸附浓缩+高低温烟气耦合干燥脱硫废水零排放技术研究”(HB2023Y02)
国电环境保护研究院有限公司科技项目“生物质固体燃料机械采制样关键设备的研究与开发”(HBJC2023Y01)。
关键词
对接焊缝
焊趾
应力集中系数
有限元
butt joint
weld toe
stress concentration factor
finite element method
