Numerical Simulation Study On Eccentric Compression Behavior Of Concrete Columns Considering FRP Bar Slip

FRP have excellent properties such as light weight,high strength and corrosion resistance,and are widely used in civil engineering fields.With the development of the times and economic progress,more and more projects will use FRP ribs,which can be used as reinforcements for buildings,replacing steel bars and preventing steel corrosion,creating a good economy for society.Benefits and social benefits.In order to study the mechanical behavior of GFRP bars under eccentric compression load,this paper uses ABAQUS finite element software to establish a finite element model,and numerically simulates the eccentric compression column considering FRP slip,and studies its effect on eccentric compression load.Under stress performance and bearing capacity.On this basis,the effects of different eccentricities,different steel bar diameters and different concrete strengths on the compression performance of FPR reinforced concrete columns are considered.The main research contents and conclusions include the following aspects:1)The finite element model of GFRP reinforced concrete columns was established by ABAQUS,and the spring 2 unit was used to simulate the bond slip between GFRP bars and concrete.The numerical simulation results show that the ultimate bearing capacity of the finite element numerical simulation is close to the experimental value,which indicates that the finite element calculation results can accurately simulate the mechanical behavior of GFRP reinforced concrete columns under eccentric compression load,and the finite element simulation is verified reliability.After the establishment of the finite element model without considering the bond slip between GFRP bars and concrete,it is found that the ultimate bearing capacity of the model is easily overestimated when the bond slip between GFRP bars and concrete is not considered.The true characteristics of concrete columns are flawed.2)In the initial stage,the load-strain curves of GFRP steel and concrete are basically similar,and the curves are basically coincident.Under the same eccentric compression load,GFRP bars have a good bonding effect with concrete,and the two can work together to participate.Stress,GFRP bars and concrete did not have obvious bond slip.As the load increases,the stress and strain of GFRP bars and concrete increase continuously,and the load-strain curve changes nonlinearly.The slope of the load-strain curve of the concrete surface at one-half of the concrete cylinder is larger than the slope of the load-strain curve of the GFRP rib.There is a big difference between the two,indicating that the reinforcement and the concrete increase with the increase of the load.There is a gradual slippage between them,and the joint effect between the two is weakened.Finally,the concrete is crushed first and the GFRP tends to break.3)With the increase of concrete strength grade,the eccentric compression bearing capacity of GFRP reinforced concrete columns increases continuously.Since the GFRP rib has a high tensile strength,the concrete column is crushed when the concrete column is broken,and the steel bar is yielded.Increasing the concrete strength grade can effectively improve the ultimate bearing capacity of the concrete eccentric compression column.4)The smaller the eccentricity,the higher the ultimate bearing capacity of the component.The larger the diameter of the GFRP rib,the higher the ultimate bearing capacity of the GFRP reinforced concrete column under the eccentric compression load.