摘要
温差循环环境下,碳纤维增强复合材料(CFRP)板加固钢结构的黏结界面受到不利影响。为探究大温差循环作用对CFRP加固开裂钢试件界面黏结性能的影响,制作了黏结剂试件和CFRP-钢试件,拟定高温为60℃,低温为25℃温差循环工况,开展了黏结剂和CFRP-钢试件的环境、拉伸试验,分析黏结剂和CFRP-钢试件的破坏模式、承载能力、界面剪应力分布、黏结-滑移关系等。结果表明:在大温差循环初期,黏结剂的抗拉强度和弹性模量略有提升,但随着温差循环次数的增加,黏结剂和CFRP-钢试件的极限荷载、界面峰值剪应力、刚度、断裂能逐渐降低。CFRP-钢试件主要表现为界面剥离和纤维剥离的混合破坏,荷载-位移曲线和黏结-滑移曲线无下降段,呈现脆性破坏特征。综上分析表明,大温差循环作用下不仅导致CFRP-钢试件界面胶层强度降低,也使黏结剂与CFRP板及钢板间黏结性能降低,二者是引起CFRP-钢试件承载力下降的主要因素。基于CFRP-钢试件界面黏结参数,建立了CFRP-钢试件黏结-滑移关系退化模型,可预测温差循环作用后试件界面剪应力与滑移量的关系,为提高加固设计的耐久性提供了重要参考。
In a thermal cycling environment,the bonding interface of carbon fiber-reinforced plastics(CFRP)(commonly used to reinforce steel structures)is adversely affected.To investigate the influences of large temperature difference cycling on the bonding performance of CFRP-strengthened cracked steel specimens,adhesive specimens,and CFRP-steel specimens were fabricated.The highest and lowest temperatures for the cyclic thermal conditions were set to 60℃and 25℃,respectively.Environmental and tensile tests were conducted on the adhesive specimens and CFRP-steel specimens to analyze the failure modes,load capacity,interfacial shear stress distribution,and bonding-slip relationship.The results indicate that,during the initial stages of large temperature difference cycling,the tensile strength and elastic modulus of the adhesive exhibit a slight increase.However,as the number of cycles increases,the ultimate load,peak interface shear stress,stiffness,and fracture energy of both the adhesive and CFRP-steel specimens progressively decline.The CFRP-steel specimens primarily display a mixed failure mode involving interface peeling and fiber delamination,with no descending sections in the load-displacement and bond-slip curves,reflecting brittle failure characteristics.In conclusion,large temperature difference cycling not only reduces the adhesive layer strength at the CFRP-steel interface but also diminishes the bond performance between the adhesive,CFRP plates,and steel plates.These two factors are the main contributors to the reduction in load-bearing capacity of the CFRP-steel specimens.Based on the bond-slip parameters of the CFRP-steel interface,a degradation model of the bond-slip relationship was established,allowing for the prediction of the interface shear stress and slip under temperature cycling.This provides valuable insights for enhancing the durability of reinforcement designs.
作者
任翔
张泽亚
孙亚民
韩琇珠
陈少杰
周浩男
REN Xiang;ZHANG Ze-ya;SUN Ya-min;HAN Xiu-zhu;CHEN Shao-jie;ZHOU Hao-nan(School of Architecture and Civil Engineering,Xi'an University of Science and Technology,Xi'an 710054,Shaanxi,China;School of Civil Engineering,Xi'an Traffic Engineering Institute,Xi'an 710300,Shaanxi,China;Organization Department of Chang'an District,Xi'an 710100,Shaanxi,China)
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2024年第10期116-127,共12页
China Journal of Highway and Transport
基金
国家自然科学基金项目(51408484,52108246)
榆林市科技计划项目(CXY-2022-157)。
关键词
桥梁工程
CFRP加固
温差循环
黏结性能
承载能力
剪应力
bridge engineering
CFRP strengthening
temperature difference cycling
bonding performance
load capacity
shear stress
作者简介
任翔(1979-),男,内蒙古呼和浩特人,教授,工学博士,E-mail:renxiang798@xst.edu.cn。
