Numerical Analysis Of Seismic Behavior Of Hybrid FRP-steel Reinforced Shear Walls

Shear wall is a kind of aseismic component with large lateral stiffness and high vertical bearing capacity,which can effectively resist the earthquake load.It is often used as the main lateral force resisting member of high-rise or super high-rise buildings.Although according to the current seismic fortification philosophy can ensure that the shear wall structure will not collapse under the action of earthquake load,but it always has lost the restoration value basically because of the serious damage and the excessive residual deformation after the earthquake.Combining the FRP bars which having linear elastic mechanical property with the concrete shear wall structure,the hybrid FRP-steel reinforced concrete(HFSRC)shear wall greatly improves the self-centering ability of the wall and also gives consideration to its seismic performance.At present,the research on the seismic performance of this new reinforced shear wall structure is not enough.In this paper,the finite element numerical method was used to further study it.A total of 18 HFSRC shear walls and 4 reinforced concrete shear walls were tested under quasi-static loading.Through the comparative analysis of the load displacement response,damage distribution characteristics and energy dissipation capacity of the wall,the seismic performance and self-recovery capacity of the HFSRC shear wall are discussed,so as to study the influence of the axial compression ratio,shear span ratio,reinforcement ratio and the type of FRP reinforcement on the seismic performance and self-recovery capacity of the HFSRC shear wall.The results showed that:(1)Deploying FRP bars in the edge members can provide the reinforced concrete shear wall with better self-centering ability and significantly reduced the the wall's residual deformation.Compared with reinforced concrete shear wall,there was 60% reduction of the residual deformation of the wall.In addition,FRP reinforcement can improve the development height of wall concrete cracks and make more concrete participate in the work.After the failure of HFSRC shear wall,the deformation of wall foot reinforcement was smaller,which is conducive to the rapid repair of the wall after the earthquake;(2)The skeleton curve of FRP reinforced concrete shear wall can be divided into three stages: elastic stage,nonlinear yield stage and nearly linear increase stage of bearing capacity.By contrast,when the reinforced concrete shear walls reached the peak load,the horizontal load reduced until the wall was destroyed;(3)With the increase of axial compression ratio,stiffness and ultimate bearing capacity of HFSRC shear walls increased gradually,and the corresponding displacement,ultimate deformation,ductility and energy consumption capacity of ultimate bearing capacity decreased gradually.Moreover,the development height of wall cracks decreased,and the damage of corner concrete aggravated;(4)With the increase of reinforced ratio of FRP bars in the edge components of shear wall,the load corresponding to the nonlinear yield stage and the nearly linear increase stage of shear walls' skeleton curve increased,the development height of walls concrete cracks increased gradually,and the failure mode of walls was controlled by the damage state of wall corner concrete.Due to the linear elastic mechanical properties of FRP bars,the change of reinforced ratio of FRP bars in the wall had little effect on the energy dissipation capacity of the shear walls;(5)With the increase of shear span ratio,the wall stiffness,bearing capacity and energy dissipation capacity of HFSRC shear wall decreased to a certain extent,but the ultimate deformation,ductility and crack development height of the wall showed an increasing trend,and the damage state of concrete at the corner of the wall reduced.When the shear span ratio is 3.5,the ultimate inter story displacement angle of the shear wall with CFRP and GFRP reinforcement is 1/40 and 1/50,respectively;(6)The types of FRP bars in the edge members had a certain influence on the seismic performance of HFSRC shear walls.The shear wall with CFRP reinforcement had higher bearing capacity and higher wall crack development height.After reaching the yield load,the linear increase trend of bearing capacity was more obvious;...