Experimental study on mechanical performance of self-centering viscous dampers with pre-pressed disc springs

A preloaded disc spring self-centering viscous damper suitable for self-centering braced frame structure was proposed to address the insufficiency of energy dissipation capacity in the existing self-centering energy dissipation braces. The construction scheme, working principle, and theoretical restoring force model of the self-centering viscous damper were introduced. The performance of the disc spring self-centering system and the viscous energy dissipation system of the self-centering viscous damper was tested, respectively. The two systems were then integrated into an integral damper, and the mechanical properties of the damper were tested. The results show that the designed self-centering viscous damper combines the advantages of the disc spring self-centering system and viscous energy dissipation system and has typical flag-shaped hysteretic characteristics. Its energy dissipation capacity increases with the increase in the loading rate. The residual deformation caused by viscous damping force in the loading process decreases with the increase of the initial pre-pressure of the disc spring self-centering system, and the residual deformation is eliminated at the end of loading. The proposed damper achieves the performance objectives of enhancing energy dissipation at high loading rates and improving self-centering performance at low loading rates. The proposed restoring force model of the self-centering viscous damper is in good agreement with the experimental results. © 2023 Science Press. All rights reserved.