Study On Seismic Behavior Of Reinforced Concrete Column With New Reinforced Steel

At present,in order to effectively improve the mechanical properties of concrete columns,various measures are usually taken to make the concrete in a three-dimensional stress state,so as to improve the strength and deformation capacity of concrete,which has been widely recognized by the academic community.Now there are three kinds of confined concrete column systems:steel tube confined concrete column,FRP confined concrete column and stirrup confined concrete column.For the study of stirrup confined concrete columns,the main factors that affect the effect of stirrup are concrete strength,stirrup type,stirrup strength and spacing.In this paper,the restraint mechanism of each type of stirrup is analyzed,and the test and numerical simulation results of composite stirrup and S-Clip stiffener are compared to verify the feasibility and rationality of the finite element analysis method in this paper.Based on the analysis of the influence of S-Clip stiffener on the seismic performance of reinforced concrete test columns,under the low axial compression ratio,the influence of a new type of stirrup,i.e.S-Clip stiffener restraint placed transversely on the seismic performance of reinforced concrete columns,is further analyzed by using ABAQUS finite element analysis software,and compared with other types of stirrups(S-Clip stiffener,composite stirrup,combination of S-Clip reinforcement and cross tie,and combination of transverse S-Clip reinforcement and cross tie).And the stress nephogram,compression nephogram,tensile damage nephogram,hysteretic curve,skeleton curve,ductility coefficient,rigidity degradation and energy consumption capacity of each specimen are obtained,which show the influence of seismic performance of the new type of reinforcement,i.e.transverse S-Clip reinforcement on concrete columns.Through comparative observation,it is found that the simulation curves of A,AS,B and BS are in good agreement with the test curves,and the error is within 15%.The area of hysteretic curve of specimens restrained by transverse S-Clip reinforcement is the largest,and the speed of load reduction is the slowest,reflecting the slowest speed of stiffness reduction.At the same time,the stirrup with transverse S-Clip stiffeners makes the specimen have better energy dissipation capacity.In addition,the higher the reinforcement ratio,the greater the ultimate load and the greater the rigidity of the specimen.By analyzing the ductility coefficient,we can see that under the low axial compression ratio,the ductility coefficient of AS ’ is 3.9%higher than that of A,and the ductility coefficient of BS ’is 1.3%higher than that of B.Therefore,compared with the effect of BS’ on ductility improvement of B,AS’ has more obvious effect on ductility improvement of A.The results show that the new stirrup configuration of AS’ specimen is most beneficial to improve the ductility of reinforced concrete columns under the low axial compression ratio.Finally,AS’ with transverse S-Clip stiffeners is selected as the research object,and its hysteretic seismic performance under different axial compression ratio is analyzed,and the axial compression ratio limit value of transverse S-Clip stiffeners is obtained.In practical application,the axial compression ratio should be reasonably limited to ensure the ductility of AS ’ columns.