Abstract
This paper investigates the structural behaviour and design of stainless-steel (SS) T-stubs connected by swage-locking pins. Sixteen swage-locking pinned SS T-stubs were tested under monotonic tension. The experimental results, including failure mode, ultimate resistance, deformation capacity and load–displacement responses, were reported. Preload measurement and tensile tests on individual swage-locking pins were additionally conducted to evaluate their preload stability and tensile resistance. Finite-element (FE) models for both T-stubs and swage-locking pins were developed and validated against the experimental data. An extended parametric study was performed to investigate the effect of key parameters—pin pitch, preload, equivalent segment length, and pin diameter—on the structural behaviour of T-stubs. The existing design methods for predicting the resistance of SS T-stubs, including the design provisions in EN 1993–1–8 (EC3) and the Continuous Strength Method (CSM), were evaluated. The results show that EC3 significantly underestimates the ultimate resistance of this connection. The CSM is a deformation-based framework that accounts for stainless-steel strain hardening and provides a higher flange plastic resistance Mf,Rd. The results indicate that the CSM improves the prediction accuracy of ultimate resistance while remaining conservative. Therefore, a new CSM-based design method is proposed for stainless-steel T-stubs connected by swage-locking pins. It combines the CSM-based flange resistance with an explicit consideration of the pin contribution. The method provides improved accuracy and consistency compared with EC3 and the CSM.