Study Of Mechanical Behavior Of External Rib Plate Joints Between Steel Plate-concrete Composite Shear Wall And Steel Beam

Steel plate-concrete composite shear walls have been widely used in high-rise buildings,and most of them are concrete filled steel tubular columns on both sides as edge members,and the joint form is beam-column joints.The external rib plate joints between steel plate-concrete composite shear wall and steel coupling beam studied in this paper eliminate the end columns on both sides of the wall.The coupling beam is directly connected with the shear wall,the structure is simple and easy to construct.But the failure mode and force performance under earthquake action require further analysis.The low cycle loading test is carried out for the external rib plate joint between steel plate-concrete composite shear wall and steel beam.The experimental phenomenon and stress distribution in the joint region of the joint are analyzed.The yield mechanism of this node is :the local buckling of the steel beam flange first occurs,and then the external buckling of the outer rib,finally the steel beam flange and the overhanging beam weld cracking.The hysteresis curve of the test piece is fusiform,the ductility coefficient is1.643~2.490,the equivalent viscous damping coefficient respectively are 0.208,0.248,0.275 and 0.173.The two main transmission path of the load are : one way is from the loading point to the overhanging beam and then the flange is spread to the outer rib to transmit the force to the shear wall;And another way is the flange directly transmit to the shear wall,in the elastic range,the ratio of two way is about 80%-95% and 5%-20%respectively.Through the analysis of test phenomenon,when the outsourcing steel plate is pulled up and separated from the concrete inside the wall,the studs provided in the wall will play a role.The finite element model of the external rib plate joint between steel plate-concrete composite shear wall and steel coupling beam is established.The influence law of steel beam span ratio and outer rib width-thickness ratio on the mechanical behavior of joints is studied by finite element simulation.The results show that with the increase of the span toheight ratio of the steel coupling beam,the hysteresis curve becomes more and more full,the rotational stiffness of the joint increases,the shear bearing capacity decreases,the bending resistance capacity increases,the deformation ability of the steel beam increases,the ductility increases;The width-to-thickness ratio of the outer rib is increased from 12.5to 15,the peak load is slightly increased,but the ductility and energy consumption are reduced.Through experimental research and finite element analysis,the ultimate bearing capacity of the joint calculated by theoretical formula is close to the test result,and the maximum difference is 13.8%.It is recommended that fillet weld size should be higher than8 mm or weld length should be greater than 150 mm of the connection between the outer rib and the flange of overhanging beam to ensure reliable transmission.And,it is recommended that when the thickness of the outer rib is 8mm,the width of the external rib should be 80mm-100 mm.