Mechanical Behavior Degradation of Bolted T-Stub Connections after Pitting Corrosion

Abstract Corrosion poses a serious threat to the safety and durability of steel structures. This paper takes the bolted T-stub connection joint as the research object and conducts a study on its mechanical properties under corrosion. By designing nine sets of test specimens, electrolytic corrosion is used to simulate the actual corrosion environment, and combined with tensile tests and finite-element analysis, the corrosion mechanism and performance degradation laws of the joints under the influence of multiple factors are deeply explored. The results show that corrosion leads to a reduction in the size of the T-stub. Corrosion pits are formed on the surfaces of the bolts and the T-stub. Under the ultimate tensile load, the corroded connections exhibited three different failure modes. The increase in corrosion ratio significantly reduces the plastic bearing capacity, ultimate bearing capacity, and initial stiffness of the joints. The parameter analysis further reveals the measures for enhancing the mechanical properties of corroded bolted connections. Using high-performance bolts can effectively enhance the ultimate bearing capacity and deformation capacity of the connections. Compared with connections using standard bolts under the same corrosion ratio of 10%, the ultimate bearing capacity of joints with high-performance bolts increased by 32.8% (specimen with preload, P) and 21.7% (specimen without preload, NP). Increasing the strength of steel can effectively reduce the impact of corrosion on the plastic bearing capacity of the connections. Increasing the plate thickness significantly enhances the initial stiffness and plastic bearing capacity of the corroded connections. This study clarifies the degradation mechanism and key influencing factors of corroded bolted T-stub joints. The findings offer valuable insights for the design, maintenance, and safety assessment of steel structures.