Mechanism Investigation on Lateral Displacement Resistance of Diagrid Structures in High-Rise Buildings

In order to study the effects of various plane forms on the mechanical performance and stiffness degradation of diagrid outer tube structures, the numerical model of a regular octagonal diagrid structure is verified by the hor-izontal pushover test. Diagrid structures with plane forms of quadrilateral, hexagon, octagon, dodecagon, and icosikaitera (24-gon) are further established. Compared with the quadrilateral framed tube structure model, the effects of plane forms on the lateral stiffness, ductility, internal force, shear lag and yield order are analyzed. Results show that the distribution range of ductility coefficient of various plane diagrid structure models is 4.27–5.22. With the number of plane edges increasing, the overall lateral stiffness increases gradually, and the better the ductility, the more reasonable the stress mechanism. In addition, since the axial force is mainly transmitted through tilted columns in diagrid structures, the shear lag effect of diagrid structures is obviously smaller than that of the frame tube structure. With the increase of the number of plane edges, the shear lag ratio of the compression flange of the diagrid structures decreases from 1.32 to 0.82. The shear lag ratio of diagrid structures with plane forms of regular hexagon, regular octagon, regular dodecagon and regular 24-gon is closer to 1.00 than that with the plane form of regular quadrilateral. In the horizontal pushover test of diagrid structures, the yield first occurred to the tilted column in the intersection area between the flange and the web with increased plastic deformation, then extended to the flange and the middle of web, and finally extended upward from the structure bottom.