Study On The Mechanical Behavior Of End-plate Splicing Semi-Rigid Joints Of Columns

The design of the node occupies a very important position in the design of steel structure, which has a direct impact on the safety, durability and economy of the steel structure.In the traditional design of steel structure, we usually think that the connection of the structure node is completely rigid connection or completely hinged. But in practical engineering applications, the performance of the joints of the steel structure is more than that of the rigid connection and the hinge.Bar splicing type semi-rigid joints of steel column designed in this thesis is firstly complete rigid the steel column with the end plate, then the steel column and the other steel column are connected by the high strength bolts on both ends of the plate. Under the combined action of the axial load of the column and the preload of the high strength bolt, the cross section of the splice joint has the ability to resist bending; at the same time, because of there has contact friction between the two end plates, that making joint section has the ability to anti shear. When structures subjected to bending moment(or shear force) is small, the section node without rotation(or slipping), and its mechanical performance reflects rigid performance; when structures subjected to bending moment(or shear force) is large, the section node will correspondingly creates angle(or slipping), and its mechanical properties reflect the performance of semi-rigid.Through the ANSYS software, the simulation model is established. We get its moment-rotation curve and shear-slip curve through the one way loading on the simulation model’s stress analysis, then draw the joint with semi-rigid shear and rotary semi-rigid conclusions. By comparing the performance of the joint model under different axial pressure, the effect of axial pressure on the dual semi-rigid of the joint model is analyzed. Through the analysis and research on the hysteretic behavior of the joint simulation model under low cycle and repeated cyclic displacement load, we draw the bending moment-rotation angle hysteresis curve and the shear-force displacement hysteresis curve; by using the MATLAB software to draw the curve of the joint simulation model, the area calculation and data processing, the energy dissipation coefficient and the equivalent viscous damping ratio of the joint are obtained; The type of the shear-slip hysteresis curve presented is shuttle, and the better energy dissipation factor and the equivalent viscous damping ratio are both used to show that the joints have better hysteretic energy dissipation and seismic behavior; but the moment-rotation hysteresis curves show a S type, and its energy dissipation coefficient and equivalent viscous damping ratio, energy dissipation and seismic performance are lower than the shear stiffness.