Previous earthquake experiences have shown that conventional yielding dampers designed for an earthquake intensity cannot perform adequately at higher intensity levels.This paper addresses this issue by proposing a two-level yielding configuration for knee-braced steel frames having an innovative deformation-controlled ring Carpet Replacement Kits damper (CRD).The proposed configuration includes a knee element damper (KED) and a CRD with a deformation-control device.In weak or moderate earthquakes, the CRD serves as the primary energy absorber.In contrast, in higher-intensity earthquakes, the deformation of the CRD is controlled and the KED acts as a secondary fuse for energy dissipation.
In this study, four traditional ring dampers with different geometric properties and two CRD were experimentally tested and their numerical models Cake / Pie Markers in Abaqus were successfully verified.The results demonstrated stable and asymmetric hysteretic curves with satisfactory ductility and energy absorption of the ring dampers.Additionally, the CRD revealed a proper control of deformation.Subsequently, a previously tested knee-braced frame specimen with the common ring damper was numerically modeled.After verifying the validity of the model, the behavior of a typical knee-braced frame equipped with a deformation-controlled multi-ring damper (CRD-KBF) was investigated and compared with a common KBF and ring-braced frame (RBF).
The obtained results confirmed the expected two-level yielding behavior of the proposed configuration.The numerical analyses demonstrated higher ductility and energy dissipation capacity of the CRD-KBF compared to the other frames.