CFL增强RC梁正截面抗弯疲劳设计  

Design for RC beams strengthened with CFL under cyclic bending loads

作　　者：韩强[1] 黄培彦[1] 郑顺潮[1] 

机构地区：[1]华南理工大学,广东广州510640

出　　处：《解放军理工大学学报（自然科学版）》2010年第6期640-646,共7页Journal of PLA University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(10672060;10272047);广东省自然科学基金资助项目(07006538)

摘　　要：FRP材料在砼结构的加固工程中已得到广泛的应用,但现行加固规程主要采用静力作用下的极限状态设计方法,没有考虑疲劳荷载作用对结构性能的影响,在结构的使用中偏于不安全。通过对等幅循环荷载下碳纤维薄板(CFL)增强RC梁三点弯曲疲劳实验,得到CFL增强梁的刚度、挠度、混凝土裂纹扩展以及CFL与混凝土的界面的疲劳损伤演化规律,揭示了在等幅循环荷载下增强梁的疲劳破坏机理;通过对CFL增强RC梁正截面疲劳极限状态的分析,考虑施加的荷载幅值、疲劳破坏模式、FRP与混凝土的粘结应力对结构疲劳寿命的影响,提出了CFL增强RC梁在等幅循环荷载作用下的正截面抗弯疲劳设计方法。Fiber reinforced Polymer（FRP） is used widely in the repairing and reinforcing of concrete structure,but the existing codes and manuals don＇t account for the effect of fatigue load on the structural capacity,which is insecure in use.An experimental study was done on fatigue behavior of RC beams strengthened with carbon fiber laminate（CFL） under the three-point bending tests.The degradation of flexural stiffness,deflection,crack propagation and CFL-concrete interfacial debonding show three stages of primary quick damage,steady linear fatigue damage and unstable damage to failure at last,and the fatigue failure mechanism was studied.By the analysis of fatigue limit state on the control section,the flexural fatigue design method for CFL strengthened beams under cyclic load was proposed.This method considers factors affecting the fatigue life of strengthened structure such as the range of applied stress levels,fatigue failure mode and bond stress between CFL and concrete.

关 键 词：碳纤维薄板 RC梁 抗弯疲劳设计 

分 类 号：U442.5[建筑科学—桥梁与隧道工程] O346.1[交通运输工程—道路与铁道工程]