Study On Elasto-plastic Analysis And Earthquake Response Of Super High-rise Frame-core Tube Structure

In recent years, with the development of social economy, more and more high-rise buildings have been designed and built,which could indirectly bring about natural disaster of the earthquake with great randomness and great destructive and eventually lead to the tremendous economic and social losses.However, owing to the higher and higher city construction and more and more complex structure recently, the design method of the elastic theory is so difficult to meet the needs of the current situation.With the improvement of the degree of seismic theory and computer technology, the elasto-plastic analysis will become more and more popular and more and more attention will be paid on it.Based on the requirement of "three level and two stage" in seismic design, this paper analyzed the structure of a super high-rise frame- core tube structure in Fuyang, Anhui.Firstly,under the effect of the frequent earthquake and wind load,the calculation results were compared,verified the rationality of the structure's indicators,which is calculated using the method of mode-superposition response spectrum based on seismic code,to ensure the overall performance of building structure and the rationality of the design of component section. Elastic time history analysis was carried out again,compared the displacement and base shear of the time history analysis with the results of the method of mode-superposition response spectrum method,ensure the accuracy of the structure seismic design under the frequent earthquake action.At the same time, through the establishment of different models and the comparative analysis,explored the significant effects of setting the strengthened story,which could reduce the lateral displacement causing by the seismic force for the complex high-rise structure.In this paper, the finite element software is used to analyze the whole structure of the static and dynamic elastic-plastic analysis.Prior to the analysis, the material constitutive relation of the finite element software is explained, and the plastic hinge model of the structure is defined.Before the pushover analysis, describes the nonlinear static analysis principle, and introduces what is the demand spectrum,capacity spectrum,and the calculation method of performance points.And in the dynamic elastic-plastic analysis method,in this paper, the hysteretic curve of beam column element for dynamic analysis is introduced, and the basic principle of seismic wave selection is introduced.Through calculation,we got the structure's displacement angle in elastic-plastic state,which is the only limit requirement for the elastic plastic state of the building structure, and the structure meets the requirement of the seismic code.More important isthat the structure design personnel can observe weather the yield mechanism of the structure is reasonable in the elastic plastic state.It can be seen in the plastic hinge picture,the frame beam and frame column's plastic hinges appear on beam ends,and do not appear on the column ends.It can guarantee the structure's second line of defense is not destroyed.At the bottom of the structure, there is a little shear failure in the core's shear wall, so it is important to take some structural measures in the bottom strengthened zone.Through the analysis of the structure elastic plastic state, it is found that the structure can meet the general performance requirements, and the yield mechanism is reasonable,and it is no collapsing with strong earthquake.The conclusion shows that the elastic plastic analysis is a reliable and effective method for the seismic design of the second stage to ensure the performance of the structure.Based on the elasto-plastic analysis of structures, structural design got out of the narrow component of pattern designing.By observing the plastic hinge and the cloud picture of destruction,we can directly see the structure of the sequence of hinges and the extent of the damage,and presents the earthquake under the weak layer,which is easily for designers to implement the seismic design concept, rather than simply from the concept of seismic seismic design to carry on the design.