Analysis Of Elastic-plastic Performance Of Reinforced Concrete Core Tube With Mixed Concealed Bracings

At present, reinforced concrete(RC) core wall is widely used as lateral force-resisting member in China's tall building structure. RC core tube with mixed concealed bracings is a newly proposed structure plan. Till now, the research on RC core tube with mixed concealed bracings is very scarce, and its engineering application is still immature. So further study is not only the need of design theory's development of tall building structure, but also significant to engineering application. In this thesis, finite element analyses by ABAQUS software are carried out to research the elastic-plastic performance of RC core tube with mixed concealed bracings.The main research works are as follows:Firstly, this thesis makes a brief introduction of basic theories of finite element analysis by ABAQUS software, including methods to establish the finite element model of reinforced concrete structure, the constitutive relation of concrete and steel bar and the selection of finite element type. Then a finite element analysis of RC core tube is conducted by ABAQUS. By comparing the results of finite element analysis and the experiment, the applicapability of using ABAQUS to conduct finite element analysis of RC core tube is confirmed.Secondly, finite element analysis software ABAQUS is adopted to do dynamic time history analysis and push-over analysis of both RC core tube and RC core tube with mixed concealed bracings. The aim is to study and compare the elastic-plastic performance of RC core tube and RC core tube with mixed concealed bracings. Then a further study is also carried out to research the effect of some parameters on the elastic-plastic performance of RC core tube with mixed concealed bracings. The parameters consist of the span-depth ratios of coupling beam, the steel ratio of corner column and the disposal mode of bracing in wall limb.In the last chapter, the basic concepts and principle of incremental dynamic analysis(IDA) are introduced. The EI-Centro earthquake wave is taken as an example to illustrate the procedure of IDA, and the elastic-plastic performance of RC core tube with mixed concealed bracings is analysed when the structure is under the action of EI-Centro earthquake waves with diffirent intensity. At last, ten earthquake waves are selected to conduct the incremental dynamic analysis, and seismic fragility analysis is also carried out to evaluate the probability of exceeding the limit states when the strcture is under the action of earthquake waves with diffirent intensity.