Improving performance of large‐span framed structure using amplified‐deformation braces with steel curved dampers

Abstract

This study focused on the seismic performance enhancement of steel framed structures with large spans. A novel brace design, comprising a pair of brace segments connected with an angle and an effective steel curved damper, forming an A‐brace, was proposed in this study. The A‐brace was adopted in the beam‐to‐column regions and was design to incur amplified deformation on the steel curved damper to enhance the energy dissipation efficiency and structural performance. A series of cyclic loading tests on one moment resisting frame and six steel frames with the proposed strengthening schemes were conducted to evaluate the effectiveness of the proposed design. Test results showed that the steel curved dampers dissipated energy in early deformation stage and sustained stable hysteretic behavior without crack until 7% story drift. Further comparisons showed that the load‐bearing capacities and energy dissipations of framed structures with the proposed A‐braces were 1.52 to 2.11 times and 1.42 to 2.00 times, respectively, those of the corresponding moment resisting frame. Simultaneous enhancements in load‐bearing capacity and energy dissipation justified the applicability of the proposed design to large span frame structural performance enhancement.