Numerical Simulation Of Seismic Damage Of Partial Steel Reinforced Concrete Frame-Core Tube Structure

Steel Reinforced Concrete frame-core tube hybrid structure is one of the widely used structures in high-rise buildings. It's with better seismic performance but not clear in the study of the mechanism and process of seismic damage in the seismic fortification zone. In the past, the beam element is used to simplify the simulation of beam and column, which can't understand the damage process of the members or local area during the earthquake action accurately. If the global coarse grid is used, the calculation accuracy is not high; The large number of units, the high requirements of the equipment and the huge computational cost are needed with global fine mesh. So, a simplified model of solid element is established by referring to a certain Steel Reinforced Concrete frame-core tube hybrid structure, to get the response under earthquake with ABAQUS.The finite element analysis with sub-modeling technique in the local key areas is help to study the mechanism and process of damage of the overall model and local members.The paper focuses on the following studies:First, a simplified model is established by referring to a certain 40 story Steel Reinforced Concrete frame-core tube hybrid structure and reasonable by comparing displacement responses under equivalent wind load between simplified model and three-dimensional model.Second, the elastic time-history analysis are used to the overall model and the response of that can be obtained. And the phenomenon with acceleration of th4 wave in the later stage of low seismic acceleration but the sudden increase of displacement is analyzed. The displacement boundary condition obtained by overall model is applied to the sub-model to obtain the corresponding seismic responses which are compared with that of overall model including layer displacement, storey drift and stress trend. It is verified that the sub-modeling technique can be applied to the structural analysis and the high precision results can be obtained at a low cost. It is reasonable and feasible.Third, nonlinear time-history analysis is made for the overall model under 7 degree and 8 degree rare earthquake with concrete damage plasticity model. The differences between structural elasticity and elastic-plastic seismic responses under rare earthquake are compared. And characteristics of structural elastic-plastic deformation, damage regions and damage evolution of structures under rare earthquake are studied.At last, Based on sub-modeling technology, nonlinear time-history analysis is madefor the key region(the bottom area of structure with 10 layer region), Partial shear wall,beam-column nodes to study Stress distribution, crack formation and development,damage and yield mechanism.The results show that: Structure can realize the seismic fortification requirements of 7 degree and 8 degree rare earthquake. Damage order and damage severity of structural members of the overall structure both are coupling beam- main beam- shear wall- column. The performance of overall structure is achieved by the damage of the structure members. The end of coupling beam and main beam form the hinge failure mechanism. A large number of horizontal bending cracks appear at the bottom of the shear wall, and the left and right side of the horizontal bending cracks run through the shear walls that its steel can suppress the crack extends to the interior shear walls. But the region and extent of damage were different under different waves. Weak damage at the bottom of the column appear but don't affects its function, the frame can achieve the design goals of strong column to weak beam. The first anti-seismic line with forming plastic hinge, but the second anti-seismic line with the feature from rotation of plastic hinge to the damage to column or shear wall base have not appeared yet. In the formation of the second anti-seismic line, the structure consumes a large amount of seismic energy to resist the earthquake action. Therefore, it is important to understand the elastic-plastic analysis method and the damage developing process of the structure,Using sub-modeling technology with avoiding excessive unit, time consuming issues to achieve a goal with low cost-high precision analysis method is hope to provide some reference for the actual project analysis.