Cyclic Behavior of T-Stub Connectors with Single-Side Bolts: Experimental and Numerical Investigation

Beam-to-column joints are critical components that transfer internal forces and ensure structural integrity in prefabricated steel structures. Their seismic performance directly affects the safety of the whole structure. To address the demand for efficient and reliable nodal connections in prefabricated steel structures, this paper proposes a T-stub connector utilizing single-side bolts and investigates its mechanical behavior under cyclic loading. Seven T-stub connector specimens with varying parameters—such as thin flange thickness, bolt type, nut welding condition, and opening direction—were designed and fabricated for low-cycle reciprocating loading tests. Their failure modes, hysteresis curves, and skeleton curves were obtained from the tests. A corresponding finite element model was developed and validated against the test results, enabling an in-depth analysis of the joint’s mechanical response. This paper presents an experimental and numerical study on the cyclic behavior of T-stub connectors with single-side bolts. Seven specimens were designed and tested under low-cycle reversed loading. The key parameters include thin flange thickness, bolt type, nut welding, and hole orientation. A finite element model was developed and validated against the test results. The results show that increasing the thin flange thickness improves the ultimate load capacity and initial stiffness, but slightly reduces the deformation capability. Among the bolt types, conventional high-strength bolts performed best. TSOB showed only a small difference in bearing capacity and a fuller hysteresis loop than EOB. Nut welding and hole orientation had little influence on the overall performance. These findings provide a basis for the design of T-stub connectors in prefabricated steel structures.