Research On Multi-cone Anchor System For Parallel Cables Of Carbon Fiber Composites

Compared with steel bars,carbon fiber reinforced composite rods have the advantages of light weight,high strength,corrosion resistance,fatigue resistance,and good creep resistance.The cables made from them can replace steel cables in prestressed concrete and bridge cable anchor structures.CFRP material is anisotropic and has high tensile strength along the fiber direction,but its shear and compressive strength is low perpendicular to the fiber,which makes its anchoring method a technical problem for the wide application of CFRP materials,therefore,the development of a new type of anchorage system suitable for CFRP cables has a great significance for advancing the application of engineering structures.This paper first conducts an experimental study on the existing multi-cone anchor system,and finds that the stress concentration at the load end,the debonding of the rodadhesive material interface are the main reasons for the low efficiency of the anchor.The finite element method is used to optimize the anchor.The stress concentration of the system is optimized for design,the CFRP rod-adhesive material interface bonding performance is studied through pull-out tests,and the adhesive system for anchoring is determined.The main research contents and results of this paper are as follows:(1)Multi-cone CFRP parallel cable anchor system: static load test of existing multicone carbon fiber cable anchor system to study its tensile mechanical properties,it is found that stress concentration,debonding,and uneven stress will greatly reduce the anchoring bearing capacity.By improving the accuracy of cable manufacturing,the anchoring efficiency has increased from 70% to 90%,but the stress concentration is still serious and there are still problems with the adhesive material.(2)Finite element simulation of CFRP cable and analysis and optimization of anchor system parameters: using ABAQUS software,a refined finite element model based on the surface-based bonding behavior is established to simulate the mechanical behavior of CFRP cable under static tension,and the test results are interrelated Confirm the reliability of the model;conduct a parametric analysis of the anchor system to determine the cause of the stress concentration phenomenon,and conduct a simulation analysis on the curved cone anchor cup form,and find that its stress distribution characteristics can well avoid the stress concentration phenomenon.On this basis,the design concept and method of the curved cone-shaped bonded anchor system are proposed.(4)Adhesive system for CFRP anchoring: Two types of adhesive systems are used to anchor CFRP rods.The pull-out test of CFRP rods is carried out.Each type of adhesive system is subdivided into five adhesive materials according to different fillers.The test results show that Tc glue is better than Ts glue.It is more suitable for CFRP rod anchoring.The bond bearing capacity of Tc adhesive system is about 40% higher than that of Ts adhesive system.It is found that the interface bond strength and fracture toughness have a greater impact on the anchoring bearing capacity.Tc is mixed with metal iron powder The resulting adhesive material is more suitable for anchoring CFRP rods.