Experimental and numerical study on the hysteretic behaviour of double-ring joints under cyclic moments

Abstract

To explore the connection reliability of double-ring joints, three groups of full-scale specimens with different structural parameters were designed. Loading tests for these specimens were conducted under the action of cyclic moments, and the failure modes and hysteretic performance of the double-ring joints were studied. In addition, the influences of various structural parameters on the hysteretic performance of the joints were explored using a finite element analysis model. The following conclusions were obtained: (1) Two failure modes, central ring fracture and bolt fracture, were observed in the experiment. For the joints in which central ring fracture occurred, the deformation and energy dissipation capacity were the strongest, and bearing capacity degradation and rigidity degradation both occurred. For the joints in which bolt fracture occurred, only rigidity degradation occurred during the loading process, and slippage existed in the moment-rotation hysteresis loops due to deformation of the bolts. (2) Energy dissipation mainly occurred in the connection region, and the energy dissipation value of the connection region was more than 70% of the total energy dissipation value. (3) By increasing the section height and central ring thickness, the rotational stiffness and ultimate bearing capacity of the joint could be improved. However, the increase in section height had little effect on the energy dissipation capacity of the joint.