Experimental Investigation On Two-story Self-centering Structure Systems Equipped With Butterfly-shaped Steel Plate Shear Walls

Self-centering steel frame with butterfly-shaped steel plate shear wall is a novel lateral resisting structure.The advantage of self-centering steel frame with post-tensioned connection and butterfly-shaped steel plate walls is combined.On one hand,the main elements could remain elastic by prestressed connection and the structure utilizes infilled butterfly-shaped steel plate wall to dissipate energy by plastic deformation,so as to effectively reduces the residual deflection.On the other hand,compared with energy consumer such as connecting angles,friction plates and friction bolted connections,butterfly-shaped steel plate shear walls have stronger energy dissipation capacity,which can be replaced quickly after earthquake and reduce maintenance costs.The main works are listed as follows:(1)The theoretical formula of initial elastic lateral stiffness of butterfly steel plate shear wall is verified by simplified combination of springs models,and the initial lateral stiffness of specimen is derived by principle of virtual work and displacement method.(2)Two-story 1:2 scaled one-bay self-centering structures,one bare frame and seven self-centering frames with butterfly-shaped steel plate shear walls were tested.The load capacity,hysteresis behavior,energy dissipation capacity,self-centering function,inner force variation of high-strength pre-stressed bar and stress distribution of crucial area were investigated.(3)Based on the experimental research,the effects of ratios between the height to thickness,the ratios between the height to width of plate walls,butterfly link stories of plate walls,and the initial prestress on the load-carrying capacity,hysteretic behavior,energy-dissipation capacity and self-centering function of specimens were studied.Results showed that the load-carrying capacity and energy-dissipation capacity of specimens were augmented with increment of ratios between the height to thickness and the height to wide of in-filled plates.However,due to increase of the ratios between the height to thickness,the residual deformation of specimens increased obviously.To some extent,while the ratios between the height to width of infill plates has ignorable effect on it.The specimens with two link stories of in-filled plates have a larger load-carrying capacity and decreased permanent deformation with an advantage of earlier energy-dissipation behavior of plates,but the final amount of consuming energy was equal to the former’s.Besides,for those specimens with relatively larger prestressed strands,their capacity of load-carrying andself-centering is stronger but weaker in energy-dissipation behavior.(4)Both theoretical and experimental analysis results show that the harmony between energy dissipation capacity and self-centering ability could be achieved by self-centering steel frame with butterfly-shaped steel plate shear wall if it is suitably designed.