HRB500与HRB400钢筋疲劳性能对比试验研究  

Comparative experimental study of fatigue performance of HRB500 and HRB400 reinforcing bar

作　　者：徐庆元[1] 方子匀 林青腾 张泽[1] XU Qing-yuan;FANG Zi-yun;LIN Qing-teng;ZHANG Ze(School of Civil Engineering,Central South University,Changsha 410075,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075

出　　处：《实验力学》2019年第1期105-112,共8页Journal of Experimental Mechanics

基　　金：湖南省自然科学基金资助项目(2018JJ2528);国家自然科学基金资助项目(51178469);国家自然科学基金-高速铁路基础研究联合基金资助项目(U1334203)

摘　　要：为对比HRB500与HRB400钢筋的疲劳性能,本文对两种钢筋进行了对称循环荷载下的轴向拉压疲劳试验。在此基础上,以Theil不等系数u和相关参数p作为精度评价指标,确定了适用于两种钢筋的威布尔分布三参数估计方法和失效概率模型,得到了HRB500和HRB400钢筋标准试件不同可靠指标下的疲劳寿命预测值,并最终建立了HRB500与HRB400钢筋中值S-N曲线和适用于高速铁路无砟轨道可靠指标为4.2的S-N曲线。研究结果表明:(1)在对HRB500和HRB400钢筋疲劳寿命三参数威布尔分布进行参数估计时,灰色预测法的精度最高;(2)HRB500钢筋在1亿次荷载循环内的疲劳性能与HRB400钢筋相比具有较为明显的优势。但随着荷载循环次数的增加,HRB500对HRB400钢筋在疲劳性能方面的优势逐渐减小。本文的研究成果可为HRB500和HRB400钢筋在高速铁路无砟轨道或其他承受高周疲劳荷载工程结构物中的选择使用提供试验依据。In this paper,in order to compare the fatigue performance between HRB500 and HRB400 reinforcing bars,the axial tension and compression fatigue experiments for their standard specimens under symmetrical cyclic loading were carried out.On this basis,the estimation method and failure probability model of three-parameter Weibull distribution parameters for fatigue life of standard specimens of HRB500 and HRB400 reinforcing bar were determined by using the relative parameters p and Theil unequal coefficient u as the evaluation index of accuracy estimation,then the fatigue life prediction values of HRB500 and HRB400 reinforcing bar standard specimens were obtained under the condition of different reliability indexes.Finally,the median stress amplitude (S)versus number of cycles (N)to failure(S-N curves)of HRB500 and HRB400 reinforcing bar and S-N curve suitable for high-speed railway with ballastless track reliability index of 4.2 were established.Results show that (1)The grey prediction can obtain higher estimation accuracy when 'estimating parameters of three-parameter Weibull distribution applicable to fatigue life of standard specimens of HRB500 and HRB400 reinforcing bar;(2)The fatigue performance of HRB500 reinforcing bar below 100 million cycles has obvious advantages compared with HRB400 reinforcing bar.However,with the increase of cycles,the fatigue performance advantage of HRB500 over HRB400 reinforcing bar decreases gradually.Above results can provide experimental basis for the choice of HRB500 and HRB400 reinforcing bar used in ballastless track of high-speed railway or other engineering structures under high cycle fatigue loads.

关 键 词：HRB500钢筋 HRB400钢筋 疲劳性能 三参数威布尔分布 应力-寿命曲线(S-N曲线) 

分 类 号：U213.244[交通运输工程—道路与铁道工程]