Experimental investigation and numerical simulation of steel frame substructure equipped with self-centering energy dissipative braces

Abstract

To verify the applicability of the developed self-centering energy dissipation (SCED) brace in the hinged steel frame structure system, two 1/2 scaled two-story hinged steel frame substructure equipped with SCED brace (SF-SCB) was designed, fabricated, and tested to study the seismic performance of a hinged SF-SCB structure. In particular, almost all seismic design of SF-SCB adopt pin connection, including column base foundations. The seismic performance of hinged SF-SCB such as the yield load, energy dissipative, and self-centering ability was studied by quasi-static test. The test results show that even if the peak story drift ratio exceeds 3 %, the hinged SF-SCB has almost no damage and destruction due to its excellent self-centering ability and pin connection design. The component gap (reserved connection gap between pin and ear plate) is the primary reason for the small stiffness in the initial stage of hinged SF-SCB loading and the large residual displacement. The performance of the SF-SCB substructure exhibits almost no degradation after multiple horizontal loads, and no damage or failure occurs in any component. Which shown that SF-SCB is completely recoverable after an earthquake and has the ability to withstand multiple earthquakes, and its components can undergo multiple repeated disassembly and recycling cycles. Furthermore, a three-dimensional full-scale finite element refinement model was established for simulation analysis. The results show that the experimental results are in good agreement with the numerical simulation results, and the established simulation model can effectively reflect the hysteretic behavior and actual stress characteristics of the SF-SCB substructure.