通过碳纤维薄板(CFL)增强钢筋混凝土(RC)梁的三点弯曲疲劳试验,得到了构件疲劳寿命曲线及其跨中挠度、抗弯刚度的演化规律;采用增强梁的剩余抗弯刚度来定义损伤变量,建立了描述其损伤、断裂过程的疲劳累积损伤模型,并对CFL增强RC梁的疲劳损伤演化历程进行了数值分析、结果表明,文中提出的疲劳累积损伤模型能够准确地描述包括混凝土开裂、CFL与混凝土剥离、钢筋屈服等破坏模式在内的CFL增强RC梁的疲劳损伤、破坏过程.
The three-point bending experiments of the reinforced concrete (RC) beam strengthened with carbon fiber laminate (CFL) were carried out, and the corresponding fatigue life curve was obtained. Moreover, the evolution histories of midspan flexibility and bending rigidity of the strengthened beam were described. The residual bending rigidity was then used to define the damage of the strengthened beam. Thus, a fatigue accumulative damage model was proposed to analyze the damage and fracture process of the strengthened beam. The evolution of the fa- tigue damage of the RC beam strengthened with CFL was finally calculated and discussed. The results show that the proposed model can correctly describe the damage and failure processes of CFL-strengthened RC beam, including the concrete cracking, the CFL debonding from the concrete and the yielding of the steel bar.