摘要
运用智能化技术将高铁简支箱梁钢筋网片骨架制作工艺从人工绑扎提升为十字焊接。本文以M1—M5共五组试件及钢筋母材为试验对象,研究焊接损伤对高铁简支箱梁钢筋网片骨架中十字焊接钢筋疲劳性能的影响,分析应力幅、应力比两个关键因素对十字焊接钢筋疲劳性能的影响。结果表明:十字焊接钢筋的疲劳破坏多发生在焊点附近,是一种典型的脆性破坏。随着应力幅降低,试件的疲劳寿命明显增大。在低应力幅下,疲劳寿命敏感性较高。随着应力比的增大,疲劳寿命减小,疲劳应力幅值减小,疲劳寿命和疲劳应力幅度对应力比敏感性逐渐增大。根据试验结果拟合了各个工况下及综合各工况整体疲劳S-N(应力幅-寿命)曲线。母材钢筋200万次疲劳应力幅约为236.49 MPa,按照存活率97.7%,修正后为230.16 MPa。M1—M5各组试件疲劳应力幅为91.87~194.03 MPa,修正后疲劳应力幅为81.19~186.10 MPa,平均值为130.36 MPa。总体上,钢筋200万次疲劳应力幅约为128.72 MPa,比母材疲劳应力幅下降了45.75%。
Intelligent technology is used to upgrade the production process of steel fabric skeleton for simple supported box girders of high speed railway from manual tying to cross welding.For the fatigue of cross-welded reinforcement,this paper conducted a fatigue test study with five groups of specimens from M1—M5 and the base metal of the reinforcement.The effects of two key factors,stress amplitude and stress ratio,on the fatigue performance of crosswelded steel bars were analyzed.The results show that the fatigue failure of cross-welded steel bars mostly occurs near the solder joints,which is a typical brittle failure.As the stress amplitude decreases,the fatigue life increases significantly.The fatigue life sensitivity is higher at low-stress amplitude.As the stress ratio increases,the fatigue life decreases,the fatigue stress amplitude decreases,and the sensitivity of fatigue life and fatigue stress amplitude to the stress ratio gradually increases.According to the test results,the overall fatigue S-N curves under various working conditions and comprehensive working conditions are fitted.The fatigue stress amplitude of the base metal reinforcement after 2 million cycles is about 230.16 MPa.According to the survival rate of 97.7%,it is 230.16 MPa after modification.The fatigue stress amplitude of each group of specimens of M1—M5 is 91.87~194.03 MPa,and the modified fatigue stress amplitude is 81.19~186.10 MPa,with an average of 130.36 MPa.On the whole,the fatigue stress amplitude of the steel bar is about 128.72 MPa,which is 45.75%lower than that of the base metal.
作者
杜闯
高启辉
宋帅
刘晓彤
张宁
DU Chuang;GAO Qihui;SONG Shuai;LIU Xiaotong;ZHANG Ning(School of Civil Engineering and Transportation,Hebei University of Technology,Tianjin 300401,China;CSTC Standard Technical Services(Tianjin)Co.Ltd.,Tianjin 300457,China)
出处
《铁道建筑》
北大核心
2024年第6期71-77,共7页
Railway Engineering
基金
河北省高等学校科学研究项目(ZD2022140)
中国铁路设计集团有限公司科技开发课题(2022-005)。
关键词
钢筋十字焊接
疲劳试验
疲劳S-N曲线
疲劳应力幅
应力比
焊接疲劳性能
cross-welded steel bars
fatigue test
fatigue S-N curve
fatigue stress amplitude
stress ratio
welding fatigue performance
作者简介
第一作者:杜闯(1976-),男,讲师,博士。E-mail:duch_1@sina.com。
