Seismic design of self-centering viscous-hysteretic devices used for steel moment-resisting frames

A force-based design (FBD) approach is proposed for steel moment-resisting frames (MRFs) with self-centering viscous-hysteretic devices (SC-VHDs) and numerical analysis is conducted on steel MRFs with SC-VHDs designed by the proposed FBD approach. The results indicate that all of these frames satisfy the peak and residual drift criteria under the design basis earthquake (DBE) and the column-to-beam strength ratio should be equal to or more than 1.8 for frames below 8 stories, whilst for frames with 8 stories or more the column-to-beam strength ratio should be equal to or greater than 1.5 to achieve the strong column-weak beam mechanism. Considering the effects of the column-to-beam strength ratio, the seismic intensity, the structural geometric characteristics, and the parameters of the SC-VHD, inelastic displacement profiles of steel MRFs with SC-VHDs are developed. Based on the proposed displacement profiles, a direct displacement-based design (DDBD) approach is proposed for steel MRFs with SC-VHDs, and the effectiveness of both the proposed DDBD approach and the displacement profiles are verified by conducting numerical analysis on steel MRFs with SC-VHDs designed by the proposed DDBD approach.