中文摘要：

通过建立循环载荷下碳纤维薄板（CFL）增强RC梁的累积损伤模型,并与增强梁的疲劳试验结果进行对比,研究增强构件的疲劳性能和损伤、破坏过程.试验发现CFL增强RC梁的疲劳损伤演化历程包括混凝土开裂、CFL与混凝土剥离、钢筋屈服等过程,具有明显的疲劳损伤成核、稳定扩展、失稳扩展三阶段发展规律,根据增强梁的载荷、挠度历程可以得到抗弯刚度演化历程.研究结果表明用CFL增强RC梁的剩余抗弯刚度来度量其疲劳损伤变量具有明确的物理意义,在此基础上建立的疲劳损伤演化方程能够准确模拟CFL增强RC梁的疲劳损伤破坏过程,进一步结合抗弯刚度可预测其剩余疲劳寿命.

英文摘要：

The fatigue behavior and failure modes of RC beams strengthened with carbon fiber laminates （CFL） under cyclic loading are studied by using an accumulative fatigue damage model based on fatigue experiments. The fatigue damage of the strengthened beams includes concrete cracking, CFL de-bonding from concrete and steel bar yielding. Three stages of fatigue damage, i.e., nucleating, steadily expanding and transiently expanding, are obvious. The damage is defined by using the residual bending rigidity of the strengthened beam with obvious physical meaning. The results indicate that the accimnulative fatigue damage model describing the damage and failure process of CFL strengthened RC beams is in good agreement with fatigue experiments, and can predict the residual fatigue lives according to the bending rigidity.