Seismic Performance Analysis Of Rocking Steelbraced Frame Structure

The traditional shaking concrete wall structure can improve the deformation mode of the structure,and then improve the seismic performance of the structure.However,due to the large weight of the shaking concrete wall,the strong earthquake action,the complex construction and the inconvenient connection with the steel frame,the shaking steel support instead of the swing wall is put forward in this paper.The shaking steel bracing frame structure consists of two parts:The first part is the framework that bearing the force which is the main body of the structure,The second part is the shaking steel bracing frame.The shaking steel bracing frame is articulated with the base.The lateral stiffness of steel braces is large,which can coordinate the deformation of each layer of the frame structure,make the displacement of each layer of the frame structure more uniform,effectively avoid the concentration of inter layer deformation easily occurring in the frame structure,and scatter the seismic energy to the various layers of the structure.Compared with the shaking concrete wall,the shaking steel bracing frame has smaller self weight,smaller earthquake action and convenient connection with the steel frame.The energy dissipation capacity of the structure is increased by the use of energy dissipation section between the shaking steel bracing frame and the main frame,so as to avoid the damage of the main structure.At present,there is little research on the shaking steel bracing frame in the world.In this paper,the finite element analysis software ABAQUS is applied to the simulation and analysis of the shaking steel bracing frame.The seismic performance of the shaking steel bracing frame is analyzed.The main contents of the work are summarized as follows:(1)referring to the relevant codes and documents,we have designed 1 shaking steel bracing frame structures with 3 layers,5 span and 15 layers by using software SAP2000,and took out a single span of 6 story structure as a BASE model for analysis.(2)the finite element model of BASE specimen is established by using ABAQUS software,and the correctness of the modeling method is verified by the simulation analysis of the existing related experiments.(3)The seismic performance of rocking steel braced structure and central braced structure is compared and analyzed by finite element analysis software ABAQUS.The results show that compared with central braced structures,the rocking steel braced framestructures has more ideal failure mode,more reasonable energy dissipation mechanism.(4)From the hysteretic curve,skeleton curve,stiffness degradation curve,ductility and energy dissipation capacity,the seismic performance of two groups of specimens with different stiffness ratios and different steel strength grades is analyzed.With the increase of the stiffness ratio between the rocking steel braced and two sides of the frame,the story drift curves of the structure tend to be a line.The bearing capacity and the remaining stiffness of the specimens increase with the steel strength rise,but the ductility decreased.(5)By simplifying the skeleton curves to the trilinear model,the replacement range of the link can be confirmed.The upper limit of the replacement range will rise with the increase of the stiffness ratio and the steel strength.(6)According to the results of the previous analysis,the self-center steel strand is added on the basis of the shaking steel bracing frame to make the structure self reset.The seismic performance of the post self-center steel strand and the influence of the steel strand pretension and the number of steel strand on the self reset performance of the structure are analyzed.