Investigation on tensile performance of T-stub connections bolted by T-bolts

The Elliptical-head one-side bolt (EOB) serves as a typical representative of the third generation of blind bolts, favored by researchers for its simple construction and impressive installation efficiency. The tensile performance of EOBs bolted T-stub connections was investigated in this paper through numerical simulation and theoretical analysis, which forms the basis for calculating the bending capacity of beam-column joints using the component method in Eurocode 3. Distinct parameters associated with EOB connections were thoroughly examined in this paper, including the layouts of bolt holes, the installation gap between bolt and hole, the rotation deviation of bolt shank, and the bolt offset within the hole. The research results indicated that a total of 5 yield line patterns emerged on the T-stub flange, which are significantly influenced by the bolt end distance and flange width. The Finite element (FE) results demonstrate that the reduction in bearing capacity for the connections bolted by EOBs is within 10% compared to those using Conventional high-strength bolts (CHBs). Adopting the vertical layout for bolt holes and avoiding bolt offset within the holes are approaches to achieving optimal bearing capacity for the connections. A bolt rotation deviation within 20° and bolt holes with rough assembly accuracy serve as guarantees for improving installation efficiency. The analysis model and theoretical equations, modified based on Eurocode 3 for predicting the yield strength of EOBs bolted T-stub connections, have been validated through FE models and can be further extended for broader application.