Study On Seismic Damage Evolution Of Steel Reinforced Concrete Frame Structure

The steel structure has been widely used in practical engineering because of its excellent seismic performance.At present,there are few studies on seismic damage of such structures.Due to the complicated force and structure of the steel reinforced concrete frame structure,the theoretical research of the steel frame structure is lagging behind the practical engineering application.In this paper,the low-cycle repeated loading test of a kind of "strong column and weak beam" type steel reinforced concrete frame structure is studied,and the mechanical properties of the steel reinforced concrete frame structure are studied: damage process,stiffness degradation,energy dissipation capacity and so on;According to the hysteresis curve and the skeleton curve obtained from the experiment,the damage process of the steel reinforced concrete frame structure is analyzed.On the basis of the experiment,the finite element software ABAQUS was used to analyze the test model by three-dimensional nonlinear finite element analysis,and the damage evolution process of the steel frame structure was analyzed quantitatively.Through the research of this paper,we get the following results:1.Steel reinforced concrete frame structure has a large deformation capacity,due to the role of the internal steel frame,the frame has reached a peak load after the strong energy consumption capacity;The damage of steel reinforced concrete frame is divided into four processes: no damage stage,initial stage of injury,stable growth stage of damage,rapid development stage of injury;The damage of the steel reinforced concrete is gradually accumulated with the increase of the number of cycles and the amplitude of the displacement.The hysteresis curve is relatively full and there is no obvious pinching phenomenon.The frame does not collapse in the destructive state,and the steel reinforced concrete frame structure has a good ductility and seismic capacity.2.The finite element software ABAQUS is used to simulate the experimental model.The simulated stress cloud image agrees well with the actual failure of the test frame.The hysteresis curve is in good agreement with the hysteresis curve obtained by the experiment,which shows that the finite element analysis more reasonable,but also from the side reflects the correctness of the results of this experiment.3.Based on the experimental results and the finite element simulation results,the damage values of the steel frame and the whole structure are calculated,it is found that the damage value of the frame is about 0.3,and the damage value is about 0.5 when the frame reaches the maximum bearing capacity,and the damage value exceeds 0.8 when the frame is damaged.The damage evolution curves of the frame beams and columns were fitted by using the polynomials.The damage evolution curves of the members were analyzed and compared.It was found that the damage of the beams in the frame was significantly worse than that of the columns,and the damage of the column rate is greater than other layers;The damage evolution curve of the whole structure of the component and the frame is a monotonically increasing process,which shows that the frame structure is an irreversible cumulative damage process under the action of the earthquake.