Numerical Simulation And Theoretical Analysis Of Seismic Performance Of Self-Centering Concrete Pier Columns Based On SMA-ECC

Compared with the traditional seismic structure,the self-centering structure has an inhibitory effect on the residual deformation caused by the yield energy dissipation of the structure,and the components can still be used after the earthquake,which can realize the rapid recovery of the structure function.Therefore,it has become one of the hotspots in the field of engineering seismic.Using intelligent materials and highperformance cement-based composite materials to develop high-performance selfcentering seismic structure system has attracted more and more scholars ’ attention and research.Shape Memory Alloy(SMA)is a new type of intelligent material,which provides a new idea for the new self-centering structural system with its unique superelasticity and shape memory effect.At the same time,the high ductility and fine cracks of Engineering Cementitious Composites(ECC)overcome the characteristics of brittleness and easy cracking of traditional concrete,and realize the self-healing ability of the structure.The combination of the advantages of these two materials can not only make the structure have the advantages of high energy consumption,high ductility,strong deformation capacity and reducing structural damage,but also make the structure have the ability of self-reset and self-healing,which can comprehensively improve the seismic performance of the structure and greatly enhance the service life of the members.This also provides more ideas for exploring new seismic design concepts.Based on the existing experimental research,this paper conducts numerical simulation of self-centering concrete pier columns based on SMA-ECC.The SMAECC pier model was established by using ABAQUS finite element software,and the numerical analysis of the seismic performance of the pier under low cyclic loading was carried out.The influence of different parameters on the seismic performance of the pier was analyzed.Based on the mechanical performance test of SMA and ECC materials,the calculation method suitable for the self-centering concrete pier based on SMA-ECC was proposed,It provides important theoretical basis for the design of selfcentering pier column structure.The main research work of this paper is as follows:(1)Analysis of the results of self-reset concrete pier test based on SMA-ECCThe design of the test model is described in detail;the test data and basic parameters of various materials such as SMA and ECC used in the test are listed;the test and test results of SMA-ECC reinforced concrete pier columns are briefly described.It is found that when the SMA-ECC composite system is applied to the bridge pier column,it is found that the bridge pier column has good ductility and selfreset ability after earthquake,indicating that the two materials can interact well and improve the seismic performance of bridge pier columns.(2)Numerical model verification of self-reset concrete pier based on SMA-ECC.According to the basic mechanical properties of materials measured by the material property test,these materials are simulated by ABAQUS finite element method to verify the correctness and applicability of the parameters of these materials in the finite element method.Through the quasi-static test of bridge pier column members,the numerical model of bridge pier column structure is constructed by ABAQUS finite element software.It is found that the data obtained by the pier model constructed in this paper are consistent with the experimental data,which shows that the model has high accuracy and good adaptability,and can well simulate the seismic effect of self-reset concrete pier based on SMA-ECC under the influence of low cyclic load.(3)Parameter analysis of self-reset concrete pier based on SMA-ECC.Through the construction of the self-reset concrete pier finite element model based on SMA-ECC,and the optimization design of the pier column,the parameters of the pier finite element model are analyzed.The design parameters such as SMA reinforcement ratio,SMA replacement length,axial compression ratio,slenderness ratio and ECC height are considered respectively,and the effects of the above parameters on the seismic characteristics of SMA-ECC concrete piers are analyzed.It is found that the configuration of SMA will affect the bearing capacity and self-reset capacity of piers,and the slenderness ratio and ECC height have more effects on the ductility and deformation capacity of piers.(4)A suitable calculation method of self-reset concrete pier based on SMA-ECC is put forward.In order to reveal the internal stress characteristics of self-resetting concrete piers based on SMA-ECC,and to grasp the mechanical characteristics of new piers more comprehensively,on the basis of the tests of mechanical properties of SMA and ECC materials,and according to the constitutive relations of SMA and ECC materials,a calculation method suitable for self-reset concrete piers based on SMA-ECC is given.The calculation method and formula derivation of load in yield state,peak state and limit state of pier column are given,which provides an important theoretical basis for the design of this kind of pier column structure.It is found that the calculation results of the proposed formula are in good agreement with the experimental values,which verifies the accuracy of the calculation method.