Seismic performance of MRFs with high strength steel main frames and EDBs

• An innovative steel MRF structure is proposed and experimentally investigated.
• The system shows several noteworthy features compared with conventional steel MRFs.
• The trilinear kinematic hysteretic model can quantify the structural nonlinearity.
• The potential of the system is reinforced by dynamic analyses.

An experiment was performed focusing on the seismic performance of a steel moment resisting frame (MRF) composed of high strength steel (HSS) members and energy dissipation bays (EDBs) with reduced beam section (RBS) beams. The behavior of the system is characterized by a damage-control stage with concentration of inelastic deformation in the energy dissipation bay (EDB), followed by a main-structural-damage stage with distributed plastification. Test results show that the system exhibits damage-control behavior and insignificant increase of residual drift in the damage-control stage. Even though the system is loaded to the stage in which inelastic deformations initiate at the main frame composed of high strength steel members, the system can deform in a ductile manner and the energy dissipation is stable. For further analysis of the system, the applicability of the trilinear kinematic hysteretic model is validated based on a proposed algorithm for idealizing the skeleton curve and the improved accuracy is achieved compared with the universally used bilinear model. Dynamic analyses are also performed based on prototype systems to validate the structural performance.