Variable curvature waveform clamping anchor for CFRP plate: Experimental investigation and theoretical model

Carbon fiber reinforced polymer (CFRP) is an anisotropic material, which presents significant challenges for anchor. The anchor design principles were first introduced, and based on the proposed anchor midline control function, the variable curvature waveform clamping anchor (VCWCA) suitable for single-layer CFRP plate was constructed. Secondly, the influence of anchor length, waveform amplitude, number of waveforms, clamping stress, and anchor form on the anchorage performance was investigated through static tensile tests. Finally, based on the analysis of the anchor mechanism, the additional friction generated by the waveform effect was quantified, and the anchor bearing capacity calculation method for waveform-friction coupling anchor was established. The results indicate that a greater variation gradient in preload led to higher anchorage efficiency for anchors with variable clamping force, but the anchorage efficiency of variable clamping force anchor was lower than that of corresponding constant clamping force anchor. Compared with the planar clamping anchor (PCA), the bearing capacity of the VCWCA could be increased by 3.32 %-15.85 %. When the clamping stress exceeded 11 MPa, the theoretical and experimental values of anchor bearing capacity matched well, with an average error of 8.08%.