Experimental and Analytical Investigation into the Mechanical Performance of a Novel Multitendon CFRP Anchorage

Abstract

Aiming to address anchoring challenges associated with carbon fiber–reinforced polymer (CFRP) tendons used as cables, this study introduces a three-segment structure CFRP-bonded anchorage and conducts tests. Building upon the verified accuracy of a finite-element (FE) model, the mechanisms underlying CFRP cable failure are analyzed. Finally, four key parameters—CFRP tendon clear spacing, friction coefficient, elastic modulus of the bonding medium, and pretension force—were selected to optimize the CFRP cable stress distribution and enhance the anchoring effectiveness. The research findings indicate that the three-segment structure anchor design achieves effective anchoring for multitendon CFRP cables, with a mean efficiency exceeding 98%. Observations during testing indicated uneven stress among the anchor system’s inner and outer layer CFRP tendons, and FE analysis suggests that the uneven stress primarily manifests as nonuniform axial stress and contact shear stress. The former may lead to failure in CFRP tendons due to the combined tension–bending stress, while the latter may result in interface failure, causing CFRP tendon slippage. Comparative analysis of stress and displacement distribution between inner and outer layer CFRP tendons in the anchor zone elucidates the mechanism of uneven stress, attributing it to the displacement lag effect between layers of CFRP tendons. Further parameter optimization indicates that applying pretension force to CFRP tendons effectively reduces uneven stress, improving the degree of combined tension–bending stress in the CFRP tendons at the loading end.