Finite Element Analysis of the Tensile Properties of Novel Bonded Anchorages for CFRP Bars

In order to reduce the slip of the bonding medium of the bonded inner conical anchorage when the CFRP bar is stressed，a novel bonded anchorage is proposed，which increases the contact area and friction between the bonding medium and the steel anchor cylinder through the setting of an inner step，and then reduces the slip of the bonding medium. In order to verify the effectiveness of the novel bonded inner stepped anchorage，the finite element models of single-bar inner conical anchorage and inner stepped anchorage were established using finite element software ABAQUS，and a comparative study on axial tensile performance was carried out. The analysis results showed that compared with the inner conical anchorage，the ultimate load of the inner stepped anchorage had increased by 10. 5%，and the bond medium slippage at the loading end had decreased by 16. 4%，indicating that the proposed novel CFRP ribbed bonding anchorage had better mechanical properties. On the basis of this analysis of anchorage parameters，the results showed that the length of the straight section of the anchorage had the greatest influence on the anchorage performance，followed by the anchorage length；the step height and the inclination angle of the anchor cup had a smaller influence on the anchorage performance of the inner stepped anchorage. Finally，the suggested ranges of the influence parameters for single-bar stepped anchorage with a CFRP bar diameter of 5 mm are given as follows：the anchoring length is 180 to 220 mm，the straight section length is 20 to 40 mm，the step height is 4 to 6 mm，and the anchor cup inclination angle is 2° to 3°.