Analysis Of Seismic Performance Of High Strength Concrete Columns Confined By Butt-welded Closed Composite High Strength Stirrups Under High Axial Compression Ratios

In this paper,the editor applys the finite element soft ANSYS to analysis theseismic performance of the high strength concrete columns confined by butt-weldedclosed composite high strength stirrups columns with different axial compressionratio or stirrup ratio.In order to perfect the seismic theory of HRC columns under highaxial compression ratio, the two parameters:axial compression ratio and stirrup ratioare refine based on the well coincidence of experiment and simulation.Main researchwork and results are summarized as follows:Firstly,a solid model is created based on the selected constitutiverelationship.The comparison of the hysteretic curves,skeleton curves,stiffnessdegradation, ductility coefficients, energy consumption indicators get from simulationand experiment shows that:1.If common nodes and discounted elasticity modulus areused in modeling,the iteration can only proceed at the85%of the bearing capacity inexperiment,and the hysteretic curves is messy.2.The peak displacement get fromsimulation is a little larger than the experiment,but the trend and peak load areconsistent with experiment.3.The ductility coefficient get from simulation is15%smaller than that of experiment,the energy consumption indicators difference is lessthan5%,so the simulate is safe to evaluate the component’s ductility.4.There issignificant difference between the initial lateral stiffness.That is because thesolidmodel does not consider the influence of the concrete cover.5.The simulation ofconcrete stress-strain nephogram tallies with the failure pattern of the actualcomponents.Secondly,two sets of stirrup ratio(0.85,0.95) and axial compressionratio(0.0449,0.0337)are increased based on the successful simulation of the test.Thesame hysteretic curves,skeleton curves,ductility coefficients of the refined simulationare detailed analysed.And,the paper fit curve between axial compression ratio orstirrup ratio and ductility coefficient.Thirdly,Test, numerical simulation and the refined simulation results show thatthe bearing capacity and the initial lateral stiffness of component are increased along with the increase of axial compression ratio and stirrup ratio.2.Fitted curve are3rdfunction,axial compression ratio(0.85~0.95)and stirrup ratio(0.03371~0.04495) arethe inflection point.3.when the stirrup ratio reach0.026564,0.027097,0.026748,0.021704,0.069406under axial compression ratio(0.8,0.85,0.9,0.95,1.0),ductilitycoefficient is equal to3.Obviously,that the axial compression ratio reaches1.0needmore stirrup ratio.4.The strength degradation of high strength concrete columnsconfined by butt-welded closed composite high strength stirrups are20%.That thestirrup ratio is0.04495or0.04903retrogression of strength are stable.Overall,strength degradation of high strength concrete columns confined bybutt-Welded closed composite high strength stirrups are stable and ductilityperformance can satisfy the requirement of seismic performance.In this paper，thesuggested elastic interstory drift angle under small seisms is1/500, the suggestedelastic-platic interstory drift angle under big seisms is1/50.The horizontal shearingcapacity of compression-bending columns deduced in this paper is consistent with theexperimental results,the error is with19%.