Research on load-bearing performance of new fabricated steel structure beam-column joints with energydissipating elements

Abstract

In this paper, a new type of H-shaped beam-column joint of assembled steel structure with additional energy dissipation elements was innovatively brought forward. The steel beam was hinged to the steel column by a pin and a connecting plate, and an L-shaped steel plate energy dissipation element was installed underneath, one side of which was rigidly connected to the steel column by a short beam and high-strength bolts, the other end of which was connected to the steel beam by a connecting plate and high-strength bolts. The energy dissipation elements exerted a low yielding strength of 235 Mpa, and the rest were Q345B. The vertical net distance between the energy dissipating element and the steel beam was constant at 200 mm, and the beam and column remained consistent. By means of altering the thickness and horizontal length of the energy dissipating element, 5 different experimental frameworks were formed. Through the experimental research and numerical simulation of 5 groups of frames, the strength, stiffness, ductility, hysteresis curve, energy dissipation coefficient, equivalent viscous damping coefficient and failure mechanism of the joints were obtained. It mainly analyzed the influence law of parameters such as the ratio of the horizontal length of the energy dissipating element to the span and of the linear stiffness of it to the steel beam on the load-bearing performance of the joint, and compared it with the traditional rigid connection beam-column joint. The research results show that the nodes were fully assembled, and the experimental research and numerical simulation results were almost consistent. When the ratio of the linear stiffness of the energy dissipating element to the steel beam was approximately 0.7, the node conformed to the seismic performance concept which the energy dissipating element was destroyed first and it was easy to replace after earthquake. When the ratio of the horizontal length of the energy dissipating element to the span was approximately 0.2, and the ratio of the linear stiffness to the steel beam was approximately 0.7, the load-bearing performance of the node was close to the traditional equivalent rigid node, which is equivalent to the rigid node of the steel frame.