Finite Element Analysis Of Plastic Hinge Length In Bending Failure Mode Of CFRP-confined Reinforced Concrete Columns

The strength-based design method has always been the seismic design method mainly adopted by national standards,but the previous earthquake disasters show that the column's sufficient deformation ability can effectively prevent the collapse of the structure.The most common way to realize the plastic deformation ability of the column is to increase the ultimate compressive strain of the concrete by applying a certain lateral constraint within the range of the plastic hinge,so that the column has the corresponding deformation ability.In this paper,the research progress of the plastic hinge length under the bending failure mode of FRP-confined reinforced concrete columns under the existing reciprocating load is reviewed.The plastic hinge length under the bending failure mode of carbon fiber cloth-constrained reinforced concrete columns is studied by numerical simulation.Firstly,the ABAQUS software was used to simulate the seismic behavior of CFRP-constrained square concrete columns.The failure modes and hysteresis curves of CFRP reinforced concrete columns obtained by finite element simulation were compared with the experimental results.The calculated results agree well with the experimental results.The feasibility of the finite element software was verified and a suitable finite element model was established.Secondly,CFRP-confined reinforced concrete columns were used as research objects.The ABAQUS finite element software was used to analyze the seismic behavior of CFRP-confined reinforced concrete columns.The optimal reinforcement method for three different reinforcement methods was obtained.Based on the optimal reinforcement method,the effects of CFRP fabric winding layer,axial compression ratio,shear span ratio and concrete strength on the seismic behavior and plastic hinge length of CFRP-confined reinforced concrete columns were studied.Finally,the plastic hinge length of CFRP-confined reinforced concrete columns is analyzed theoretically in the bending failure mode.Combined with the existing calculation formula of plastic hinge length and the comparative analysis of the finite element simulation results,statistical analysis and verification were carried out with the help of statistical test data.According to the results of multiple groups of models calculated by the finite element method,the proposed formula of plastic hinge length of CFRP restrained reinforced concrete column in bending failure mode was given by the method of multiple linear regression.