Approach Of Modifying The Constitutive Model Of Reinforcing Bars Accompanied By The Impact Of Buckling And Lateral Expansion Of Concrete

Under strong earthquake, the ends of column in the reinforced concrete framestructure designed according to the current specification in our country will hinge moreor less. In some conditions, the buckling of longitudinal reinforcement in columnappears. And this leads to a rapid reduction of capacity of column, eventually leadsto structural damage, even collapse. Therefore, to evaluate the seismic performance andthe performance of standing up to collapse of reinforced concrete structure, it is full ofgreat significance to establish accurate constitutive model considering buckling oflongitudinal reinforcement.This research is based on the model established by Gomes and Appleton[5](G-Amodel), and two stages are adopted to modify this model. Stage one, the G-A model ismodified to simulate the cyclic test of reinforcing bar accurately. Stage two, this modelis modified to consider the impact of the lateral eapansion of concrete.After the modifying is completed, the effectiveness of the modified model isvalidated through comparison with available experimental data of three groups ofreinforcing bar tests and three groups of reinforced concrete column tests. And theresult indicates that the modified model is able to simulate all the tests more accuratelythan G-A model and ReinforcingSteel model.