| In this paper, the composite frame of Concrete Filled Steel Tubular (CFST) column combined with Steel Reinforced Concrete (SRC) beam is researched. As a new and economic structure system of high-efficiency and also energy-saving, composite frame has been applied more and more widely in railway station construction.The main work and conclusions are as follows:(1) Based on the plane cross-section assumption, the SRC section is meshed by the layer method. A transformation process which changes material to section is made via Matlab, and a restoring force model of SRC beam based on material is obtained by taking considering bond-slip into consideration. Another restoring force model of CFST column based on sections is also derived according to Han Linhai's theory of CFST beam-columns.(2) A frame of single span under quasi-static load controlled by displacement control. The efficiency of the proposed customized Plastic Hinge Mode is proved by comparing the customized Plastic Hinge Model and Fiber Model.(3) For the composite frame of CFST column combined with SRC beam, plastic hinge under different beam-column's linear stiffness ratio is analyzed and compared, and then a rational beam-column's linear stiffness ratio is obtained.(4) The seismic behavior of composite frame of CFST column combined with Steel SRC beam under strong earthquake is analyzed by the pushover analysis method and the elastic-plastic dynamic analysis method. Results shows that the seismic resistance of the frame is well, as well as the development of the plastic hinge, and the inter-story drift satisfy the requirements of the Seismic Codes. The structure meets the code of strong column and weak beam, and is in a state of"Immediate Occupancy(5) The results of pushover analysis and elastic-plastic time history analysis with different seismic acceleration are compared. The top displacement and inter-story drift measured in elastic-plastic time history analysis by the proposed model is larger。There are differences between the results obtained by these two methods, and the dispersion will increase as the acceleration of earthquake wave. The result obtained by pushover analysis in the areas of low seismic fortification intensity is underestimated but relatively precise, so it can be considered as safety. However, the result measured by the pushover analysis tends to be insecurity, and needs to to be amended or reanalyzed by elastic-plastic time history analysis. Besides, the amount of the plastic hinges of the two analysis methods is nearly equal, as well as their order of appearance and distribution. |
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