Investigation On Seismic Performance Of Energy Dissipation Shear Wall Structure With Mild Steel Damper

The reinforced concrete shear wall structure is applied to the high-rise and super-high-rise buildings in China’s earthquake zone.However,the traditional reinforced concrete shear wall has poor deformation and energy dissipation performance,and these characteristics lead structure to be prone to brittle shearing or crushing damage under strong earthquakes,which is an embodiment of low seismic energy consumption.In addition,wall damage are always concentrated in the plastic hinge area at the bottom of the wall and it is not conducive to post-earthquake repair.Due to the uncertainty of the earthquake disasters that may be encountered in the future,the structure designed according to the passive seismic design method cannot meet the safety requirements of the structure.In order to improve the deformation and energy dissipation performance of the reinforced concrete shear wall structure under the earthquake,aiming to shortages of the traditional shear wall,The double X-shaped mild steel damper is installed at the vertical joint,and a new type of internal soft steel damper is proposed.The double X-shaped mild steel damper is installed at the vertical joint,and a new type of internal mild steel damper is proposed.To study the seismic performance of this structure,this paper mainly carried out the following work:1)First of all,the normal reinforced concrete wall was slotted vertically,and the finite element model of the shear wall with mild steel damper was established.The hysteresis energy dissipation of cast-in-situ shear wall,shear wall with vertical joint and shear wall with soft steel damper were analyzed respectively under cyclic load.The analysis shows that the existence of vertical joint obviously changes the mechanical characteristics of the wall.Although the energy dissipation capacity of the wall has been improved to a certain extent,its lateral stiffness and ultimate bearing capacity have been lost more.The results show that the presence of vertical joints and dampers significantly changes the force characteristics of the wall.After the wall is slotted,the lateral stiffness and ultimate bearing capacity are weakened,and the energy consumption capacity is improved but not obvious.When the mild steel damper is placed at the position of slit,the stiffness and bearing capacity of wall are greatly restored.After the wall enters the nonlinear stage,the deformation and energy consumption of the wall are obviously improved,and it has good seismic performance.2)The effects of different axial compression ratios,embedded column positions and different positions of damper,such as the failure modes,bearing capacity and ductility of slit wall with damper were studied.The research shows that the axial compression ratio increases,the ultimate load and stiffness of the shear wall become larger,and the ultimate displacement,ductility and energy dissipation performance are smaller as the axial compression ratio becomes larger,but the performance of damping wall effected by the different axial compression ratios is not sensible.On the other hand,the hooping rate of the restraining zone on both sides of the vertical slit has a great influence on the energy consumption of the wall.If the energy consumption of the wall is to be improved,some certain measures need to be taken.In addition,The position of the damper is largely influential,In principle,it should be position at the maximum relative displacement,In this paper the lower middle location of wall is more adaptive.3)Taking the core tube of a frame-tube structure as the research object,the ABAQUS finite element analysis model of the ordinary reinforced concrete shear wall structure and the energy-saving shear wall structure with soft steel damper were established respectively,then the dynamic elastoplastic time history analysis of the established model was carried out.The numerical results show:when the strength of seismic input is small,the seismic response of the energy-consuming structure is equivalent to the cast-in-place shear wall structure.After the seismic input is larger,the displacement response of the main structure is obviously more reduced the original one,and the damage of the structure is also slightly smaller,these mean that the energy-consuming shear wall structure with double X mild steel damper has a certain damping effect.