Experimental Study On CFRP Cable Prestressed Structure Connected Anchorage

With the birth of new structures and the development of new materials,the contemporary architecture have shown infinite possibilities.With the birth of Construction Industry 4.0,people's requirements for construction projects are getting higher and higher,more and more new structures are widely used in new materials.Carbon fiber composite reinforcement(hereinafter abbreviated as CFRP)is a new high-strength composite material that has the advantages of light weight,high strength,corrosion resistance,and etc.Mechanical properties are also quite junior.According to studies,the CFRP cable suspendome structure is generally superior to the steel cable structure in terms of static performance and stability.In order to truly apply the new material CFRP in the long-span space structure,the first task is to establish a suitable CFRP cable anchor solid system.This paper was supported by the National Natural Science Foundation of China(No.1721480027)and the National Natural Science Foundation of China(No.51608234).The design and manufacture of CFRP cable suspendome structures carried out,prestressed loading and structural loading tests were performed.The main contents and results of the study are as follows:(1)Grouting for CFRP cable anchors.For the previous generations of the research group,the gluing process was optimized,and an excellent gluing process was developed.With this gluing process,the maximum load-carrying capacity of CFRP ribs can be more stably exerted.(2)Based on the cohesion force model,the bearing capacity formula of CFRP cable anchorage and the analysis of static load rebound curve.The mechanical analysis of the static load process of CFRP cable anchors was carried out,and the force mechanism in the process of bond slip was discussed.With reference to many bond-slip constitutive equations,based on the traditional cohesion force model,the bearing capacity formula of the specimen during static load was deduced.At the same time,the springback curve in the static load process is analyzed and the constitutive equation is established,and the analytical solution of the constitutive relation is solved.(3)Finite element analysis of CFRP cable suspendome.The MIDAS software is used to do rough calculations on the chord-supported dome structure.The relevant parameters of the mid-diameter cable and the girder are extracted from the simulation results and used as the design value of the anchorage device.(4)Performance test for anchorage of CFRP anchor.Based on the results of finite element calculations,after several improvements,the anchorage structure was optimized,and the specific dimensions of the CFRP cable-stayed sill and cable anchors were determined,and the anchorage performance was verified by the anchorage test.(5)Design and Fabrication of anchors for CFRP cable suspendomeThe cable anchors,rope anchorages and joint anchorages for CFRP cable suspendome structures were designed and manufactured.Using the mature gluing process,after several optimizations,the originally designed anchorage was optimized.(6)Stress Distribution Analysis of CFRP cable suspendomeThe working conditions of the anchorage were analyzed through the data collected in the chord support dome test.Through the prestressed tensile test and structural loading test,the distribution of the stress in the anchorage zone of the CFRP cable along the longitudinal direction of the reinforcement was observed during the test.It shows that during the loading process,the stress distribution in the anchorage zone of the cable anchor consists of five phases.In each phase,the stress at the free end is always the maximum.The interface stress at each site increases with loading.Before the critical stage,the stress of the central cable is less than the stress at the loading end;after the critical stage,the stress in the middle is greater than the stress at the loading end;the stress at the free end of the cable is always higher than that of other parts in each stage.Finally,the paper points out some problems that should be solved in the application of the CFRP anchor system in chord-supported dome structures and puts forward some suggestions.