Experimental Study On Lateral Stiffness For Assembled Frame Bracing Wall

The assembled Frame bracing shear wall structural system is a new kind of shear wall structural system,There are certain gaps between the frame bracing wall and other components.It only takes reinforced to vertically connect with other components at the edge of the wall.According to the processing of boundary condition,the frame bracing wall is equivalent to the diagonal bracing wall,which makes the frame bracing wall in this system can work together with frame collaborate inner diagonal bracing wall in the form of force.At the same time,the frame bracing wall is designed into hollow wall to reduce the self-weight of the structure,it also can reduce the function of the earthquake.This structural system can reduce the connection of reinforced,it has the advantages of clear transmission,simple structure and fast construction speed.The Frame bracing shear wall studied in this paper is one of the main load components of the assembled shear wall structure system.Its lateral performance and lateral stiffness are the core of the research on the calculation theory and design method of the Frame bracing shear wall structural system.In this paper,a low cycle reciprocating load test is carried out on 10 Frame bracing wall with different angle of equivalent brace,axial compression ratio,and a wall with edge reinforcement.The mechanical properties of the wall of the Frame bracing wall are studied and the following conclusions have been obtained:(1)The failure modes of the Frame bracing wall specimens are basically the same,and the concrete first crack on the side of the wall and the bottom beam,the initial crack is in horizontal direction,and the development of cracks increases gradually along the diagonal direction,later,the reinforced which in the wall is yield and the concrete is crushed off.(2)The angle of the equivalent brace is an important factor affecting the lateral stiffness of the Frame bracing wall.With the smaller angle of the equivalent bracing,the lateral stiffness of the bracing wall increases.When the angle of equivalent brace of the Frame bracing wall is 30 degrees,it’s elastic stiffness is about 5.8 times as much as of the 60 degrees,and the 45 degrees is about 2.8 as much as of the 60 degrees,the 30 degrees is about 1.6 times as much as of the 45 degrees.(3)The axial compression ratio is a key factor in Frame bracing wall lateral stiffness,in a certain range,with the increase of axial compression ratio,the displacement of the wall in the same horizontal load is decreased and the lateral stiffness of the Frame bracing wall increases obviously.When the axial compression ratio of the Frame bracing wall is 0.3,it’s lateral stiffness is about 1.09 times as much as of the 0.2.(4)A wall with edge reinforcement have little effect on the lateral stiffness of the Frame bracing wall,but it has great influence on the maximum load and maximum displacement of the wall in the elastic stage.(5)The theoretical formula derived from the mechanical model of lateral stiffness of Frame bracing wall is established,which makes the calculated results agree well with the experimental results,which can provide theoretical basis for the lateral stiffness calculation of walls.By simplifying the wall of frame bracing wall to "cross pole + vertical bar" model.The simplified model has the same bending stiffness and shear stiffness as the original wall,and the equivalent substitution relationship between the bar and the lateral force wall is established.In the elastic phase,the structure system can be equal to the structural calculation of the bar model,and the amount of calculation is greatly reduced.