A novel integrated sleeve-wedge anchorage system for multi-tendon CFRP cable utilized in cable roof structures: Concept and numerical investigation

Abstract

Carbon fiber-reinforced polymer (CFRP) cables demonstrate exceptional mechanical properties and offer significant potential for utilization in large-span cable roof structures. However, the implementation of efficient CFRP cable anchorage systems specifically designed for cable roofs remains an urgent necessity. In this paper, a novel integrated sleeve-wedge anchorage system (NISWAS) consisting of two components, a multi-channel integrated sleeve-wedge (MCISW) and a barrel, has been proposed to achieve the anchorage of CFRP cable with multiple tendons. Compared to the traditional wedge-type anchorage system (WTAS), which can only clamp a single CFRP tendon, the use of the novel integrated steel wire anchorage system (NISWAS) reduces both the volume and self-weight of the cable anchorage end, significantly improving construction efficiency. The design concept of NISWAS was validated through finite element method (FEM) as an example of a 6-Φ5 CFRP cable, and its anchor performance was systematically evaluated. Three key factors affecting the anchor performance were analyzed: the slope angle of MCISW, the anchor length and the differential angle between barrel and MCISW. The results show that the NISWAS is an effective way of anchoring multiple CFRP tendons, and the design of the MCISW can prevent excessive transverse stress on the CFRP cable at the loaded end of the anchorage. The slope angle of the MCISW exerts the most significant impact on the anchor performance. The optimal choice of angle is 3°, beyond which the effect of the anchorage system on the sliding of CFRP cable becomes less significant, while excessive transverse stress may cause premature failure of the cable. The differential angle between barrel and MCISW has a secondary influence on the anchor performance. A moderate angle difference value (0.1° to 0.2°) can alleviate the transverse stress on the CFRP cable, but a too large value (more than 0.3°) will reduce the force transmission between the MCISW and barrel, resulting in premature cable pullout. Increasing the anchor length can reduce transverse stress and cable slip, but the reduction effect is not significant. After analysis, the anchor length of 90 mm can satisfy the anchoring requirement. According to the influence law of the above three factors, the parameter design scheme of the NISWAS was finally proposed.