Chui-Hsin Chen, Ananda Insan Firdausy, Shan-Xuan Wu
This study investigates the inelastic cyclic responses of hybrid steel-timber braces with restraining plates (HSTBs-RP), in which glulam timber filler was clamped between double steel core plates and then stiffened using steel restraining plates tightened by bolted fasteners. Five full-scale HSTBs specimens were designed and experimentally tested under cyclic loading, with the different parameters observed included the steel core plate sections, glulam timber sections, and configurations of restraining plates. With this strategy, the glulam timber filler provided additional lateral support to the core plate components, delaying the accumulation of plastic strain and stress concentration that could otherwise lead to plastic hinge initiation. The results indicated that the HSTBs-RP successfully delayed premature fracture while significantly prolonging fatigue life cycles, where all tested brace specimens exhibited fracture failure after enduring a substantial number of cycles under fatigue loading at severe deformation, which are beneficial for applications in structures at risk of insufficient resistance to low-cycle fatigue. Moreover, the designed braces exhibited sufficient peak strength and stiffness. However, the expected cyclic performance was not fully achieved due to overall buckling occurring at the outer ends of core component segments, which were not covered by bolted fastener confinements within the restraining plates. To further optimize cyclic performance, design improvements should be implemented by extending the covered length of the restraining plate confined by bolted fasteners beyond the transition segment of the core plate component, which is expected to mitigate global buckling and ensure that fracture occurs within the yielding segment. © 2025 Institution of Structural Engineers
Department of Civil Engineering, National Yang Ming Chiao Tung University, Taiwan; Department of Civil Engineering, Brawijaya University, Indonesia
