Experimental Study And Finite Element Analysis On Hysteretic Behavior Of Corrugated Mild Steel Damper

The metal damper is often used in the special parts of structures because of its large initial stiffness,good hysteretic performance and simple structure.It is one of the most effective methods in energy dissipation and damping technology.As a new type of plate formed by cold rolling of flat steel plate,corrugated steel plate has the advantages of large out-of-plane stiffness,good stability and high elastic buckling capacity.And the low-yield-point steel is a kind of steel with great deformation capacity,stable strength and good fatigue property.Therefore,in this paper,a new type of corrugated mild steel damper is proposed by combining the two advantages.Through the experimental study and numerical simulation,the mechanical properties,the effects of different parameters on the mechanical properties and its damping effect in steel frame are studied.The main research contents and achievements are as follows:(1)In this paper,two kinds of corrugated mild steel dampers with different structures are proposed,and their structural characteristics are introduced.The energy dissipation plates are made of BLY160 low-yield-point steel.In order to study the mechanical performance of the corrugated mild steel dampers,the quasi-static test under the cyclic load was carried out,and the corrugated steel plate dampers with the energy dissipation plates made of Q235 steel are compared and analyzed.The test phenomenon and the mechanical mechanism of each test specimen are mainly analyzed.And the hysteretic behavior,bearing capacity,energy dissipation capacity,deformation capacity,degradation of equivalent stiffness and the bearing capacity,and the strain of energy dissipation plates are analyzed and discussed.(2)The mechanical properties of two kinds of corrugated mild steel dampers arecompared.It is found that the corrugated mild steel dampers have good energy dissipation capacity and stable bearing capacity.In contrast,the horizontal corrugated mild steel damper has better energy dissipation capacity and ductility,while the vertical corrugated mild steel damper has larger initial stiffness and bearing capacity,however,its stiffness degradation is faster.In addition,compared with the corrugated steel plate dampers with energy dissipation plates made of Q235 steel,the two kinds of corrugated mild steel dampers have better ductility.(3)In this paper,the ABAQUS is used to model and analyze the test specimens,and the accuracy of the model is verified by comparing the test.Furthermore,36 models are established in order to expand and analyze the influence of the thickness of the energy dissipation plates,the wave angle,the wave length,and the height-width ratio of the web plates,the thickness ratio of flange plate and web plate,and the initial defect rate on the performance of dampers.The results show that energy dissipation capacity,the bearing capacity of the horizontal corrugated mild steel damper are proportional to the thickness of the energy dissipation plates,the thickness ratio of flange plate and web plate,and is inversely proportional to the height-width ratio of the web plates.In addition,with the decrease of the wave angle and the increase of wave length of the web plates,the energy dissipation capacity of the dampers increases,however,the bearing capacity and the initial stiffness of the damper decrease.For the vertical corrugated mild steel damper,the bearing capacity and energy dissipation capacity are proportional to the thickness,wave length,thickness ratio of flange plate and web plate,and are inversely proportional to the wave angle and the height-width ratio of the web plates.In addition,the stiffness is proportional to the thickness of the energy dissipation plates and inversely proportional to the height-width ratio,while the wave angle,wave length and thickness ratio have little effect on the stiffness of the dampers.In contrast,vertical corrugated mild steel dampers are more sensitive to the initial defects.(4)The dampers with better energy dissipation capacity and ductility are installed in the steel frame,and the elastic-plastic seismic response analysis under frequently and rarely occurred earthquake is carried out.The research indicates that two kinds of corrugated mild steel dampers can effectively reduce the horizontal displacement of thetop floor and story drift ratios of the steel frame,and have a better damping effect.And the horizontal corrugated mild steel dampers can basically meet the working requirements in steel frames.