Experimental and numerical study of an innovative combined damper using steel pipes and bars

Purpose This study introduces an innovative passive damping system featuring a unique damper, termed the Pipe-Bar Damper (PBD), which is constructed by integrating steel pipes and bars into a fuse unit. The PBD operates in two distinct stages to enhance ductility and efficiently absorb energy of braced frames during seismic events. This damper can provide exceptional performance under significant deformations, highlighting its unique ability to effectively dissipate seismic energy. Design/methodology/approach The proposed novel system is subjected to experimental testing within a single diagonally braced frame under cyclic loading conditions. By utilizing bolt connections, the damper can be swiftly and effortlessly replaced after damage, significantly reducing downtime and maintenance efforts. Additionally, the new system is modeled in ABAQUS software to compare the numerical and experimental results. Findings The experimental findings confirm the anticipated multi-level functionality of the damper, demonstrating its ability to effectively dissipate energy across varying force levels. The newly developed system demonstrates a tolerance for a relative drift of approximately 3% at the onset of steel pipe fracturing. Meanwhile, the steel bars within the system are capable of withstanding higher drift levels without fracturing, thereby enabling the system to maintain stability even at drifts exceeding 3.5%. Furthermore, this system is capable of achieving a ductility index exceeding 6.0 while maintaining its strength without any degradation. Finally, the new system was simulated using ABAQUS software, and the simulation results closely matched the experimental results. Originality/value To enhance the performance of braced frames using dampers, a few studies have explored dampers operating in two stages. This study introduces a unique combined damper, utilizing steel pipes and bars, which has not been previously investigated. The primary objective was to address the low ductility commonly observed in braced frames and to improve energy dissipation. As a result, the research offers an important reference for improving the performance and seismic energy absorption capacity of braced steel structures.