Study On The Secondary Development Program Of Bond Model Based On ABAQUS

In the nonlinear analysis of reinforced concrete structures,the analysis of the bondslip problem between steel and concrete is very important,especially the analysis of the bond performance of corroded steel bars.The correct bond-slip constitutive model is the key to study the bond performance between steel and concrete.At present,the spring element is often used in the finite element software to simulate the bond slip problem of reinforced concrete,but it has limitations for the simulation of reinforced concrete structures under repeated loads.Therefore,domestic and foreign scholars have carried out a lot of research on the reinforced concrete bond-slip element,and proposed a variety of bond-slip element,but the research on the element to more accurately simulate the problem remains to be deepened.Therefore,based on the ABAQUS secondary development platform,the algorithm and program for the bond-slip relationship between steel and concrete are studied by developing a new element,so that it can accurately simulate the reinforced concrete bond slip under repeated loads considering corrosion factors.The specific work is as follows:(1)Considering the damage of concrete and using FORTRAN language to write the concrete D-P(Drucker-Prager)constitutive model program with damage.And verify the correctness of the program by analysis the concrete stress.(2)Study the bond-slip constitutive relation between reinforcement and concrete,establish the bond-slip element modle under repeated loads considering corrosion factors,study the finite element algorithm of the model,and write the element user subroutine in FORTRAN language.And also verify the validity of the program by analysis the loadslip curve of the loading end reinforcement.(3)Based on the reinforcement drawing test of the research group,the finite element model of the drawn specimen was established by using the concrete D-P constitutive model considering the damage and the three-dimensional bond slip element model.Compare the model analysis results with the experimental results to test the rationality and feasibility of the user program of the bond-slip element.(4)In order to further study the applicability of the element,based on Li Jinbo’s test on the influence of corrosion on the seismic performance of reinforced concrete columns,by using the concrete D-P constitutive model considering the damage and the threedimensional bond-slip element model,establish the finite element model of the reinforced concrete column under the repeated loads.Compare the analysis results with the finite element model results of unbonded slip and experimental results to verify the correcty of quadrilateral sliding element in the analysis of the bearing capacity of reinforced concrete columns.