碳纤维-光纤光栅板加固钢筋混凝土梁疲劳性能试验研究  

Experimental study on fatigue performance of reinforced concrete beams strengthened with CFRP-OFBG plates

作　　者：邓朗妮[1] 周峥 黄晓霞 雷丽贞 廖羚[1] DENG Langni;ZHOU Zheng;HUANG Xiaoxia;LEI Lizhen;LIAO Ling(School of Civil and Architectural Engineering,Guangxi University of Science and Technology,Liuzhou 545006,China)

机构地区：[1]广西科技大学土木建筑工程学院,广西柳州545006

出　　处：《建筑结构学报》2022年第12期91-101,共11页Journal of Building Structures

基　　金：国家自然科学基金项目(51568008)。

摘　　要：为明确碳纤维-光纤光栅(CFRP-OFBG)板加固对钢筋混凝土梁疲劳性能的提升作用,对5根采用内嵌光纤光栅应变传感器的碳纤维板加固的钢筋混凝土梁和两根未加固梁进行静载和常幅疲劳试验。分析了不同应力水平下碳纤维-光纤光栅板加固梁的疲劳破坏模式、疲劳寿命、跨中挠度、应变演变等情况,并与未加固梁进行对比。结果表明:随着疲劳循环次数增加和疲劳荷载幅值的增大,整个试验过程疲劳破坏呈现四阶段发展规律;加固梁跨中挠度、钢筋拉应变、混凝土压应变变化趋于平缓,直到疲劳破坏才会发生突变。其中,CFRP-OFBG板对加固梁疲劳应变监测数据与电阻应变片数据吻合良好;在相同循环次数和疲劳荷载限值下,加固梁的疲劳变形较未加固梁的有所减小,加固梁承载力比未加固梁提高约45%。通过理论分析和试验结果拟合,推导剩余强度公式,提出一种基于剩余强度的疲劳累积损伤模型来预测疲劳寿命。相比于试验结果,采用该模型所预测加固梁的疲劳寿命偏大,误差为8.57%。To clarify the fatigue performance of reinforced concrete beams strengthened with carbon fibre reinforced plastic-optical fibre bragg grating(CFRP-OFBG)plates,static and constant-amplitude fatigue tests were carried out on five reinforced concrete beams strengthened with carbon fiber reinforced plastic(CFRP)plates with embedded optical fibre bragg grating(OFBG)strain sensors and two unstrengthened beams.The fatigue damage mode,fatigue life,mid-span deflection and strain evolution of the CFRP-OFBG plate-strengthened beams were analysed under different stress levels and compared with the unstrengthened beams.The results show that as the number of fatigue cycles increases and the amplitude of fatigue load increases,the fatigue damage shows a four-stage development pattern throughout the test,with the changes in mid-span deflection,tensile strain of reinforcement and compressive strain of concrete in the reinforced beams levelling off until fatigue failure occurs abruptly.In particular,the fatigue strain data from the CFRP-OFBG plates on the reinforced beams agrees well with the strain gauge data.For the same number of cycles and fatigue load limits,the fatigue deformation of the reinforced beams is reduced compared to unreinforced beams and the load capacity of the reinforced beams is increased by 45%compared to the unstrengthened beams.Through theoretical analysis and fitting of test results,a residual strength formula was derived and a fatigue cumulative damage model based on the residual strength was proposed to predict the fatigue life.Compared to the experimental results,the fatigue life of the reinforced beams predicted by the above model is relatively large,with an error of around 8.57%.

关 键 词：钢筋混凝土梁 碳纤维-光纤光栅板 疲劳试验 疲劳寿命预测 剩余强度 累积损伤模型 

分 类 号：TU375.1[建筑科学—结构工程] TU317.1