Component Tests of Huge Scale All-Steel Multi-Curve Buckling Restrained Braces

Abstract

Many countries have gradually adopted the buckling-restrained brace (BRB) for preventing structural damage during earthquakes since its introduction in the 1970s. In this study, we propose an all-steel BRB called the multi-curve buckling-restrained brace (MC-BRB) to overcome the shortcomings of traditional BRBs that use mortar encased in a steel tube. This new BRB consists of double core plates, each with multiple neck portions that form multiple energy dissipation segments, enlarged segments, lateral support elements, and constraining elements that are designed to prevent the BRB from buckling. The enlarged segment located in the middle of the core plate can be connected to the lateral support and constraining elements to increase buckling strength and prevent the lateral support and constraining elements from sliding during earthquakes. The lateral support elements can be windowed to allow quality control checks to be performed and the condition of the core plate to be monitored after an earthquake. In this study, a huge-scale component test with an axial load of 14000 KN in the core plates was carried out to investigate the behavior of the new BRB and its capabilities for seismic mitigation. A comparison of the experimental results and theoretical calculations indicate that the all-steel MC-BRB possesses a stable and predictable mechanical behavior under cyclic loadings.