Simulation Study on Seismic Performance of Square STSRC Column-Steel Beam Joints Incorporating Reclaimed Resin-Bonded Wood Fiber Concrete

To advance the application of Reclaimed Resin-Bonded Wood Fiber Concrete (RRWFC) in steel tube-confined steel-reinforced concrete (STSRC) structures, this study designed six hybrid joint specimens comprising square STSRC columns with RRWFC concrete and steel beams. A numerical analysis model was developed using ABAQUS finite element software. The hysteretic behavior, stress distribution, failure modes, and energy dissipation capacity of the joints were investigated. Parametric studies examined the influence of four key variables on seismic performance: wood fiber replacement ratio, internal steel reinforcement configuration, joint region height, and axial compression ratio. The results show that the joints exhibit complete hysteretic curves and favorable energy dissipation capacity. Their stress distribution and failure modes conform to the strong column–weak beam–stronger joint principle of seismic design. Furthermore, a tri-linear skeleton curve model and restoring force model were established for the joints. These findings provide a robust theoretical foundation and practical computational models for implementing RRWFC in seismic-resistant structural systems.