Analysis Of Mechanical And Damping Properties Of Bending-shear Compound Graded Yield Dampers

Energy dissipation damper is a kind of energy dissipation damping technology which is widely used at present.Through the research and analysis of displacement metal damper,it is found that the initial stiffness and yield displacement of bending yielding metal mild steel damper are small,which can not adapt to the energy dissipation work under different intensity earthquake.In view of this problem,combining with the current design concept of phased energy dissipation of dampers,the design idea of bending-shear composite graded yield dampers is proposed based on the existing curved steel plate dampers by combining shear yielding mild steel bars with curved steel plates.The specific research content of the composite damper is as follows:(1)Based on the design idea of BSCD,two kinds of bending-shear composite graded yield dampers(PC-BSCD and EC-BSCD)were designed by changing the connection mode of arc steel plate.The numerical models of these two kinds of composite dampers were established by using the finite element software ANSYS.The preliminary finite element analysis shows that: The bending-shear composite graded yield damper can make up for the defect of insufficient initial stiffness of the arc steel plate,and the stress distribution is uniform,which can ensure that the different energy dissipation members enter the plastic state of energy dissipation under the cyclic displacement loading of different amplitude,so as to achieve the goal of phased yield energy dissipation.(2)After considering the four factors of mild steel bar diameter,radius,width and thickness of arc steel plate,numerical models of bending shear composite graded yield dampers with two connection forms are respectively established for comparative analysis,and the influence of composite damper parameter changes on energy dissipation performance is studied.The results show that the initial stiffness of composite damper increases with the increase of mild steel bar diameter,and its energy consumption increases with the increase of mild steel bar diameter The radius and thickness of the arc steel plate increase rapidly,and the width of the arc steel plate has little effect on the energy dissipation performance of the composite damper;The hysteretic curve of the bending shear composite graded yield damper with eccentric connection of arc steel plate has better symmetry and more stable energy dissipation performance than that of the composite damper with the same connection.(3)Put forward curved scissors complex hierarchical yield dampers three linear restoring force model and the composite damper,the mechanical properties of the wallbeam fitting formula,set up four groups of model specimen as a validation set,and the numerical analysis and the fitting formula of superposition,comparing the computed results can be concluded that the numerical model analysis results and the restoring force model computed results have high degree,The overall error is not more than 9%.The restoring force model and the formula for calculating the mechanical properties can well describe the mechanical properties of the flexural shear composite graded yield damper.(4)The flexural shear composite graded yield damper in the form of ectopically connected was selected.Combined with the actual engineering cases,SAP2000 was used to analyze the time history of the traditional seismic structure and the energy dissipation and damping structure equipped with the composite damper under seismic conditions.The seismic responses of the two structures were compared and it could be found that:The composite damper can provide about 1.84% additional damping ratio to the structure,and reduce the seismic response of the structure and the plastic deformation of the components by dissipating the seismic energy,so as to enhance the seismic performance of the structure.Figure [58] Table [21] Reference [61]...