Experiment Study Of Self-Centering Steel Frame With Single Butterfly-Shaped Steel Plate Shear Wall

Self-centering steel frame with single butterfly-shaped steel plate shear wall is a new load-resisting structure which consists of a steel frame with self centering conncetions and butterfly shaped steel plate shear walls.The two sides of the butterfly-shaped steel plate shear walls don’t connect with columns,which reduces the additional bending moment to columns.The self-centering connection is adopted to make the structure recenter after the earthquake.In this dissertation,the single butterfly-shaped steel plate shear wall,the self-centering steel frame and self-centering steel frame with single butterfly-shaped steel palte shear wall,by the way of combined theory,experiment and numerical simulation,were studied systematically from the load-bearing mechanism and hysteretic behavior.The main works are listed as follows:(1)An innovative butterfly-shaped steel plate shear wall suitable fot self-centering structure was proposed.A simplified mechanical model for butterfly-shaped steel plate shear wall was put forward.Theoretical strength,flexibility,elastic initial stiffness and post-buckled stiffness of butterfly-shape steel plate shear wall were formulated,and then verified by numerical analysis.Finite element analysis of the butterfly-shaped steel plate shear wall was conducted to study the parameters of span-width ratio and height-thickness ratio.The results show that the proposed butterfly-shaped steel plate with dent of waist possesses pretty close load capacity to the steel plate shear wall with two-side connection,but more pinched hysteresis loop.The dent of waist doesn’t change the angle of tension field.The initial elastic stiffness,elastic post-buckling stiffness,equivalent viscous damp ratio and theoretic strength of the steel plate shear wall all increase in different extent with respective raising of span-width and thickness of plate.Butterfly-shaped steel plate shear wall can provide stable energy dissipation for self-centering structure.The failure mode of butterfly-shaped steel plate shear wall is mainly caused by tension field.(2)The mechanical performance of the self-centering steel frame was analyzed.The results show that the lateral stiffness of the self-centering steel frame is mainly dependent on the area of the steel strand after the self-centering conncetions decompression;when the area of the steel strand is determined,the effect of the frame recentering is relative to the span height ratio,the thickness ratio of the butterfly-shaped steel shear wall and the vertical load imposed on the frame,Compared to infilled rectangular steel plate shear wall,the butterfly shaped steel plate shear wall has a better self-centering capacity.(3)The experimental study of single butterfly-shaped steel plate shear wall shows that the single butterfly-shape steel plate shear wall has higher load-capacity,initial stiffness,good ductility performance,stable energy dissipation and pinched hysteresis loops,which could be applied to the self-cenering structure.(4)Self-cetering steel frame,self-centering steel frame with rectangular steel plate shear wall and self-centering steel frame with single butterfly-shaped steel plate shear wall specimens have been tested.The results show that the self-centering steel frame can be completely recentered and the connections have no plastic deformation;the recentering capacity of self-centering steel frame with single butterfly-shaped steel plate shear wall specimen is better than that of self-centering steel frame with rectangular steel plate shear wall specimen,but the energy consumption is slightly lower than that of self-centering steel frame with rectangular steel plate shear wall;the mechanical performance of specimens is consistent with the theoretical analysis.(5)By adjusting the mass scaling factor,the ABAQUS explicit solver can effectively simulate butterfly-shaped steel shear wall specimens.In order to simplify the simulation of the hysteretic behavior of butterfly-shaped steel plate shear wall,a hysteretic theoretical model of plate was proposed using thelink element.The skeleton curve and hysteretic criteria are also given.The simplified model comprehensively considers the effect of specific contribution of plate compressive region.By modifying the constitutive curve in the PERFORM-3D software,the application of the simplified model in the finite element software is realized by combining with the test results of butterfly-shaped steel plate shear wall,the accuracy of the simplified hysteretic model is verified.By using the connector element to simulate the self-centering connection,the ABAQUS software was used to simulate the self-centering steel frame with single butterfly-shaped steel plate shear wall specimen.Comparing the experimental results,ABAQUS can effectively simulate the self-centering structure.(6)The effect of height to thickness ratio,span height ratio and weakening width of the butterfly-shape steel plate shear wall on the recentering performance of self-centering steel frame with single butterfly-shaped steel plate shear wall is analyzed by numerical simulation.The results show that the self-centering steel frame with butterfly-shape steel plate shear wall has better recentering performance with the decreasing of butterfly-shape steel plate shear wall thickness and span height ratio.