| Concrete-filled steel tube has superior mechanical properties, and therefore has been applied in practical engineering more and more widely, especially in high-rise and super high-rise buildings. In general, concrete-filled steel tube forms composite structures with steel or reinforced concrete. China is a nation with high—frequency of earthquakes, so if want to promote the concrete-filled steel tubular composite structure more widely, we must have a full understanding of seismic behaviors of this composite structural system. However, the studies on seismic behaviors of concrete-filled steel tubular composite structure is deficient, for this structure is a new type.In order to investigate seismic behaviors of concrete-filled steel tubular composite structure, a ten-storey concrete-filled steel tubular composite frame structure is selected in this paper, and A three—dimensional finite element analysis model of this structure is established based on ANSYS, then three aspects is studied as follow:(1)Modal analysis for this model is conducted to get the dynamic characteristics of this structure. (2) Elastic time history analysis for this model is carried out to obtain the response of this structure under frequently occurred earthquakes,the difference in seismic response of this structure influenced by different unidirectional,unidirectional and bidirectional seismic wave,unidirectional seismic wave which inputted from different direction are analysed.(3) Elastic time history analysis for this model is performed under frequently occurred earthquakes while used different damping models,damping ratio and strength grade of concrete filled in concrete-filled steel tubular columns, the influence of damping model selection,damping ratio value on the calculating results of this structure's seismic response is analyzed,the damping ratio range of the hole structure is given by comparing the seismic response of this structure under stiffness proportional damping with the one under stiffness proportional damping for material, and the influence of the change of concrete strength grade on this structure's seismic response and the different value of the calculating results of this structure's seismic response under different damping model is studied. |
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