Experimental Research on Hysteresis Performance of Energy-Dissipating Braces Composed of Rectangular Steel Tube and Perforated Web Plates

When a concentrically braced steel frame structure is subjected to seismic fortification-level or rare earthquake action， the central brace often loses its bearing capacity due to the buckling instability of diagonal brace members under compression. To prevent brace instability， an energy-dissipating brace composed of a rectangular steel tube and perforated web plates is proposed. This brace not only retains the advantages of the central brace， but also incorporates the benefits of metal dampers. Under fortification-level earthquakes， the metal dampers installed at both ends of the square steel tube of the brace yield first and dissipate seismic energy， thus ensuring that the square steel tube of the brace remains in an elastic state at all times. A quasi-static loading test was conducted on an energy-dissipating brace. The effects of different arrangements of perforated energy-dissipation plates on the brace’s hysteretic performance， bearing capacity， stiffness degradation， and energy dissipation capacity were studied. The experimental results indicated that the brace was mainly dissipated by the yielding of the inter-perforation plate components of the energy-dissipating plate. The hysteresis curve of the specimen was full， demonstrating good energy dissipation capacity. During the loading process， the force-transmitting square steel tube of the energy dissipation brace always maintained elastic， but the brace failed due to the failure of the perforated web plate. Before the specimen lost its load-bearing capacity， there was no sudden decrease in strength or stiffness， and the brace did not become unstable during the loading process. Under cycles of the same magnitude， the brace's strength did not degrade significantly.