Multi-dimensional Seismic Analysis Of Stee Frame-core Wall Structures Using Endurance Time Method

Earthquake will cause great damage,and earthquake action should be considered during design phase of building structures.Therefore,we need to carry out seismic design of building structures.In recent years,steel frame-core wall structures have been built increasingly in China.The structure system can make full use of the characteristics of steel structures and concrete structures,and has high construction speed,light weight,high bearing capacity,good ductility and seismic resistance and so on.The structure consists of components of different materials.The mechanism and characteristics of vibration damping are different in each part.When the structure is subjected to earthquake,failure mechanism is unclear.At present,domestic and foreign scholars have not fully concerned about this aspect.Most of them only consider unidirectional seismic action and ignore the influence of multi-dimensional seismic action.Pushover and IDA are the two most commonly used structural performance evaluation methods at present,but they all have their own defects.In this paper,a new type of structural seismic analysis method-endurance time method,is used to analyze seismic response of steel frame-core wall structures,and compared with IDA results to study its effectiveness.The main research works are as follows:(1)Research status of steel frame-core wall structures,evolution of seismic design method and proposal of performance-based seismic design method are introduced.The shortcomings of present seismic analysis method are pointed out,and endurance time method is put forward,and the generation process of endurance time accelerograms is described in detail.According to Chinese standard response spectrum,three endurance time accelerograms are generated.(2)MIDAS/GEN modeling stage,pre and post processing mode,analysis function,structural component simulation type,and IDA method are briefly introduced.According to Chinese seismic code,natural ground motions are selected from PEER earthquake ground motion database.A 12-story and 50-story steel frame-core wall structure was constructed using MIDAS/GEN,and a finite element model is defined.(3)Horizontal unidirectional and bidirectional seismic action on the structure are carried out by using endurance time accelerograms and natural ground motions,and the most unfavorable input angle is considered in bidirectional seismic input.Based on the results of IDA,the accuracy of endurance time method is tested,and the difference of the structural response under unidirectional and bidirectional seismic action is compared.(4)This paper analyzes the distribution of maximum inter-story drift ratio and maximum story shear,the ductility ratio of the components,and the distribution of plastic hinges under small,medium and large earthquakes,and analyze s the structural damage development process,and determines the reasonableness of two seismic protection lines for the structural system.