Design And Performance Simulation Of Mild Steel Damper For Prefabricated Concrete Structure

Because of the secondary pouring of concrete joints in the construction of prefabricated concrete structures,the integrity of the connections of prefabricated components is worse than that of cast-in-situ concrete structures,which leads to the poor seismic performance of prefabricated concrete structures as a whole,and limits the application of the structural system in high-rise buildings and high-intensity areas.In order to improve the seismic performance of prefabricated prefabricated concrete structures,in view of the special problem of relatively weak connection between prefabricated members and the excellent energy dissipation performance of mild steel,the mild steel dampers for beam-column joints of frame structures and the mild steel dampers for connecting beams of shear wall structures were proposed.In view of the above problems,the main research contents and achievements of this paper are as follows:(1)A new type of mild steel damper for beam-to-column joints of prefabricated concrete frame structures was designed to overcome the relative weakness of beam-to-column joints.In order to improve the energy dissipation efficiency of materials,the fulling yield energy dissipation element was obtained by optimizing the shape of the energy dissipation element.The finite element software ABAQUS was used to simulate and analyze the different structures of the fulling yield energy dissipation element and the beam-column joint damper.The results show that under external loads,all sections of the fulling yielding energy dissipation element yield at the same time in its preset energy dissipation section.When the load increases gradually,the yield area in each section increases gradually until each section reaches the energy dissipation state of the full section yield,which improves the energy dissipation efficiency of the material;the moment-rotation hysteresis curve of the beam-column joint mild steel damper Full and excellent energy dissipation performance,its energy dissipation capacity is related to the size an d layout of fulling yield type energy dissipation components;it can meet the energy dissipation design requirements by modifying the relevant parameters in the theoretical design formula of beam-column joint mild steel damper.(2)In order to improve the seismic performance of prefabricated concrete shear wall structures,based on the fulling yield energy dissipation elements,a new kind of mild steel damper with connecting beams installed in the middle of the conne cting beams of shear walls was proposed,and the mild steel dampers with different structures were simulated and analyzed.The results show that the force-displacement hysteretic curve of the damper is full,its energy dissipation performance is excellent and its energy dissipation capacity is strong;its energy dissipation capacity increases with the increase of the number of fulling yield-type energy dissipation elements,but it has nothing to do with the location and arrangement of energy dissipation elements;the performance parameters of a single fulling yield-type energy dissipation element can be calculated by means of combination superposition.Performance parameters of mild steel damper.(3)In order to study the influence of mild steel dampers on the performance of beam-column joints of prefabricated concrete frame structures,numerical simulation analysis was carried out by ABAQUS on beam-column joints of prefabricated concrete frame structures and beam-column joints of prefabricated concrete frame structures with mild steel dampers at beam-column joints.The results show that the beam-to-column joint mild steel damper changes the failure mode of beam-to-column joints of prefabricated concrete frame structures,and makes the joint failure as far as possible away from the post-pouring area of concrete and the core area of the joints,which are relatively weak in beam-to-column connections,so that the structure meets the design requirements of "strong joints,weak components";the beam-to-column joint mild steel damper effectively improves the prefabricated assembly.Ductility,lateral stiffness and energy dissipation capacity of beam-column joints in concrete frame structures.(4)In order to study the effect of beam-column joint mild steel dampers on the overall seismic performance of prefabricated concrete frame structures,the seismic numerical simulation of prefabricated concrete frame structures and prefabricated prefabricated concrete frame structures with beam-column joint mild steel dampers was carried out.The results show that the flexible steel damper with beam-column joints improves the overall seismic performance of prefabricated concrete frame structures,and reduces the inter-story displacement of the structures under seismic action.