Experimental Research On Seismic Behavior Of 600MPa Rc T-shaped Columns And Finite Element Analysis

Experiment of T-shaped section concrete columns with 600 MPa steel bars under axial compression and low cyclic laterally reversed loads are presented in this paper.Based on the described test phenomenon,the strain curves of the steel bars,bearing capacity,hysteretic behavior,skeleton curves and stiffness degradation were analyzed as well as the energy dissipation.Meanwhile,some factors were discussed on the influence of seismic behavior,such as stirrup spacing,axial compression ratio and reinforcement strength.Experimental results indicate that,with the increase of stirrup spacing,the number of cracks are smaller and the width of crack is larger.Reducing stirrups spacing can improve the destruction of displacement and ductility.The specimen with larger axial compression could restrain the fracture and the plastic hinge on bottom.The ultimate bearing capacity and the overall rigidity of the specimens are increased,but its ductility is decreased by increasing axial compression.And the compressive strength of the 600 MPa steel bars on the outer side of the flange and the web in the T-shaped columns plays a role well.The T-shaped columns with 600 MPa steel bars have high bearing capacity and sufficient energy-dissipating capacity,the seismic performance are favorable.In this paper,finite element software ANSYS was used to simulate the test specimens.The calculated mechanical properties and hysteretic curves were in good agreement with the test.On this basis,the influence of concrete strength,steel bar strength and reinforcement ratio on the seismic behavior such as load capacity,hysteretic curve and stiffness degradation were analyzed.The results show that the ultimate bearing capacity and its displacement increase by increasing the strength of concrete,but the stiffness degradation is reduced.With the improvement of the strength of the steel bar,the ultimate bearing capacity and the deformation capacity increase,and the stiffness degradation of T-shaped columns can be alleviated.The specimens with larger reinforcement ratio have larger initial rigidity,higher ultimate capacity and displacement,and larger deformation capacity.