The Analysis Of Hysteretic Behavior And Failure Mechanism For Reversing V Shape Eccentrically Braced Semi-rigid Steel Frame

In practice, The joint stiffness is always between fully rigid and ideal pinned connections. In fact, it belongs to semi-rigid connections. Domestic and overseas scholars have made some achievements on it. The eccentrically braced steel frame is a kind of superior seismic system which enhances the lateral stiffness of framework and has more superior seismic performance than centrally braced steel. The research on the mechanical behavior of the framework considered both the eccentrically brace and joint stiffness is rare. So the study of eccentric semi-rigid steel frame in the hysteretic behavior and failure mechanism has some engineering significance.This paper studies the hysteretic behavior and failure mechanism of eccentric semi-rigid steel frame.The Study includes test and ANSYS simulation analysis and the ANSYS simulation is the main part. Test is to verify the feasibility of the model. The cyclic tests are V-shaped eccentrically braced steel frames and V-shaped eccentrically braced semi-rigid steel frames. Results of the experiment shows that the hysteresis curves of frame with welded connections and end plate connections are very full. On the contrary, the hysteresis curves frame with angle connections and T connections are not full and fold phenomenon occurs.Experimental support for the V-shaped eccentric semi-rigid steel frame hysteresis tests, test results show that:welded joints with the end plate connections hysteretic behavior of eccentrically braced frame well and steel nodes and T nodes braced angle steel frame hysteretic phenomena of molded more serious. Control in the ANSYS simulation, the yield load, yield displacement, ultimate load, ultimate displacement of almost the same, but the test itself ANSYS model error and the limitations of spring element, the energy coefficient varied.In order to more further investigating the destroy mechanism of the reversing V-shaped eccentric semi-rigid steel frame, the article design 4 series (altogether 28) of finite element analytic models on the test foundation. Through to analysis 4 series of finite element analytic models, to investigate the relations between frame parameters and the reversing V-shaped eccentric semi-rigid steel frame's hysteretic behavior, these parameters include the frame's span number, the beam-to-column connection's rotation rigidity, the connection's type and so on. The results show that:The lateral stiffness and energy dissipation properties of the eccentrically braced steel frames are affected seriously by joint stiffness. The hysteretic behavior of eccentrically braced steel frame is better in pace with joint stiffness and the cross number increasing. In addition, with the joint stiffness increasing, the stress distribution of link beam after yielding is more uniform, shearing deformation is more obvious, it's better to play a "fuse" effect.Finally, the seismic characteristics of the reversing V-shaped eccentric semi-rigid steel frame is summed up based on the results of experimental research and ANSYS analysis. Compared to other types of eccentrically braced steel frames, the reversing V shape eccentrically braced steel frame is not the optimal choice and the paper analyzes the shortcomings and given the improvement measures.