Hysteretic behavior and numerical evaluation of a novel pre-compression friction spring RC rocking column with enhanced segment

This paper presents a novel pre -compression friction spring rocking column (PFSRC) with enhanced segment to improve the seismic resilient of RC frames. The construction of PFSRC is described in detail, the pre -compression friction spring device (PFSD) and PFSRC are analyzed theoretically in turn, and proposed a theoretical hysteresis model of the PFSRC. Subsequently, preliminary parametrically of the PFSRC were designed, and numerical simulation of friction springs and PFSD was carried out by ABAQUS, respectively, to validate and analyze their mechanical properties. Lastly, a simplified simulation method of PFSDs was proposed for the first time, based on which the FE model of the PFSRC was established, and numerical simulation was conducted on PFSRC under cyclic loading. The results indicate that the theoretical hysteresis model was consistent with numerical simulations, revealing that the PESRC exhibits a "flag -shaped" response and no residual drift. Plastic deformation was not observed in the RC column, except for the center of rotation in the steel tube. PFSDs effectively improved the initial stiffness, load capacity and dissipate majority energy for the PFSRC. As the increase of the axial force, the load capacity of the PFSRC increase, while no significant effect on the initial stiffness. The steel tube effectively protect the concrete at the foot of the column from being damaged; the curvature of steel tube concrete column is larger than that of the upper RC column, and its curvature increases with height, while the curvature of the RC column remains constant, and the curvature will change abruptly at variable section. When the drift exceeds 1 %, the neutral -axis depth will remain at 0.16, and the drift of the column base is always smaller than that of top of PFSRC, and the error becomes larger as the drift increase.