Finite Element Analysis Of Flexural Behavior On Reinforced Concrete Beam With HRB500 Bundled Steel Bars Based On ANSYS

As the engineering structure of high-rise,long span and leave load more and more common,especially the large amount of steel in the structure of the transfer beams and beam-column joints,reinforced components directly gets intensive,which brings great difficulty to the construction and quality control.To overcome this problem,the steel bars are reinforced two or three tied together in the arrangement of concrete,that is,bundled bar.The change of construction of steel bar from single bar to bundled bar,cause beam bar anchorage of concrete and steel bars changed,which affects the bearing capacity,stiffness,crack width and the connection problem of the beam,especially impact on the high strength reinforced bar.Thus,the influence of the bundled bar in the high strength reinforced on concrete beam remains to be further studied.In this paper,finite element analysis of reinforced concrete beam with HRB500 bundled steel bars was carried out.The similarities and differences between the test and the finite element simulation are analyzed by comparing the finite element numerical simulation results with the experimental results.Meanwhile,influence of bond-slip on simulated reinforced concrete beam with bundled steel bars was studied.The main contents of this paper are as follows:(1)The finite element numerical simulation of reinforced concrete beam with HRB500 bundled steel bars was carried out by ANSYS.The characteristics of reinforced concrete beam with bundled steel bars in deformation,stress,strain,loaddisplacement curve and crack propagation were analyzed.Compared the loaddisplacement curve,the numerical simulation results are in good agreement with the experimental results.(2)The failure form of reinforced concrete beam with HRB500 bundled steel bars is similar to that of reinforced concrete beam with single reinforcement,which is in accordance with the characteristics of flexural failure of reinforced beam.Compared with reinforced concrete beam with single reinforcement,the ultimate bearing capacity of reinforced concrete beam with bundled steel bars is slightly reduced and the range was less than 5%.Therefore,the bearing capacity calculation formula of the beam in China can be designed according to the current "Concrete Structure Design Code".(3)Analyze the influence of whether considering bond-slip between steel and concrete,the longitudinal reinforcement ratio,concrete grade and different bond-slip constitutive relations on simulated reinforced concrete beam with bundled steel bars.The simulation results showed that the finite element simulation results of the reinforcement and the constitutive relation between the reinforcement and the concrete that considered by the bond-slip test are closer to the bending test results of the reinforced concrete beam than the finite element simulation results without the bondslip;The load-displacement curve of reinforced concrete beam with single reinforcement is basically the same as that of the test bond-slip constitutive relation when the reinforced concrete beam with bundled steel bars was simulated by the Jin zhisheng bond-slip constitutive relation and Houde's empirical formula.And the loaddisplacement curve of reinforced concrete beam with bundled steel bars is slightly different in the elastic-plastic phase,and the trend of elasticity and plasticity is basically the same.With the increase of longitudinal reinforcement ratio,the influence of bundled steel on the bearing capacity of beams increases slightly,the influence range is less than5%,the influence of bundled steel on deflection is decreased slightly,and the influence range is 0~5mm.With the increase of concrete grade,the influence of bundled steel on the bearing capacity of beams increases slightly,the influence range is less than 5%,the influence of bundled steel on deflection is decreased slightly,and the influence range is0~2mm.(4)By combining the cases of the use of HRB500 bundled steel bars in the actual engineering,the advantages of the reinforcement and the construction measure in the actual engineering are explained and the corresponding structural measures are needed to show that the bundled steel bars can also guarantee the bearing capacity,deflection and cracks Requirements,and bundled steel bars for the future application and promotion of important practical significance.