Study On Performance Of New-style Composite Frame Under Low-reversed Cyclic Loading

Based on the analysis of some problems about the common steel-concrete composite beam, this article puts forward a new type of steel-encased composite beam. We have completed static test of simple-supported steel-encased composite beam and experimental study on seismic performance of steel-encased composite joint under low-reversed cyclic loading successfully. We find that it is worthy of further research on this new kind of structure so that we carry out experimental study of seismic performance of the frame model. The frame model is composed of steel-encased concrete composite beams (SCCB) and steel reinforced concrete columns.The details of research are followings.(1)We generalize the formula of steel-encased concrete composite beam, steel reinforced concrete column and steel-encased composite joint. It is the theoretic foundation of this experiment.(2)Experimental study on seismic performance of the frame model under low-reversed cyclic loading is carried out. Hysteresis behavior, ductility, energy dissipation and degeneration are studied systematically. The experimental result shows that this frame meets the requirement for seismic design and has excellent seismic performance. It is worthy of being broadly applied to the multistory residential buildings.(3)Numerical simulation is conducted by finite element method .At first, a 3-D finite element model of this composite frame model is proposed. Then we get ultimate carrying capacity of the frame model under monotonic loading. Compared with the experimental results, the computational results of the model are found accurate and this computational model can be applied in structure analysis of this kind of composite frame.