Non-linear Analysis Of The New Steel-encased Concrete Composite Frame Structure

Based on the analysis of some problems about the steel frame, concrete frame, and common steel-concrete composite frame, this article selects a new type of steel-encased composite frame to research. The column of mis composite frame is the reinforced concrete column, and the beam is new type of steel-encased composite beam. Concrete is poured into the new type of composite beam's U-shape section and served as the rib of the T-shape composite beam. Its flange adopts cast-in-situ concrete floor. The web and concrete flange floor are integrated by shear connectors.FEM nonlinear analysis, EP nonlinear analysis and Test research have been carried out in this article to study the new type of composite structures and compared to the congener structures. The details are as followings.(1) Numerical simulation is conducted by nonlinear finite element method. The ultimate capacity under monotony load and the hysteresis curve, the ultimate capacity, the ductility coefficient under low cyclic reverse load of frame are acquired.(2) The nonlinear el-plastic theory model of the composite frame is analyzed. The whole failure process of structure was observed. The frame experienced the crack/ yield/ ultimate and failure process.(3) Compared the experiment, new type steel-encased concrete composite frame under low cyclic reversed load, which has been finished, to the analysis results by FEM method and EP method, including the failure modes, the hysteresis curve, the skeleton curve and the ultimate capacity etc.(4) The steel-encased composite structures are contrasted to the congener structures in seismic behavior and cost. Finally, Construction design suggestions and research expectation of this new type of steel-encased concrete composite frame are advanced according to the results of test research, theoretical analysis and computer simulation.