This paper investigates the fatigue performance of CFRP (carbon fiber-reinforced polymer) cables using a bond-extrusion anchorage system in which the variable stiffness of the bonding medium in the steel sleeve is adopted. A group of cyclic loading experiments under a maximum stress of 0.45$f_u$ and a stress range from 500 MPa to 900 MPa were carried out to determine the fatigue damage evolution of the cable anchorage assemblies. In addition, the fatigue failure mechanism and the influence of cyclic loading on the mechanical performance, such as the stress and stiffness of the cable, the relative displacement of the anchorage assemblies and the stress of the steel sleeve, were also investigated. The results indicated that the stress range primarily affected the fatigue life of the cable anchorage assemblies. The damage of the anchorage assemblies was generated in the cable at the outer-layer tendons, which first forms longitudinal cracks, then splits and finally results in rupture. The axial strain of the cable was still linear, and the axial stiffness decreased by 8% compared with the initial stiffness after 1.2 million cycles under a stress range of 500 MPa. The stress variation in the steel sleeve was not obvious with cyclic loading. The fatigue performance for the anchorage assemblies was obtained and it could realize 2 million cycles below the design stress range of 470 MPa based on the trend analysis from the fatigue experiment.

本文研究了采用粘结-挤压锚固系统的CFRP（碳纤维增强聚合物）电缆的疲劳性能，该系统采用钢套中粘结介质的可变刚度。一组最大应力为0.45的循环载荷实验$F_{ü}$在500 MPa至900 MPa的应力范围内确定电缆锚固组件的疲劳损伤演变。此外，还研究了疲劳破坏机理以及循环载荷对机械性能的影响，例如电缆的应力和刚度，锚固组件的相对位移以及钢套的应力。结果表明，应力范围主要影响电缆锚固组件的疲劳寿命。锚固组件的损坏在外层腱的电缆中产生，首先形成纵向裂缝，然后裂开，最后导致破裂。电缆的轴向应变仍然是线性的，并且轴向刚度与1之后的初始刚度相比降低了8％。在500 MPa的应力范围内进行200万次循环。钢套筒的应力变化在循环载荷下不明显。根据疲劳试验的趋势分析，获得了锚固组件的疲劳性能，在470 MPa的设计应力范围内可以实现200万个循环。