Investigation on tensile resistance of stainless-clad steel bolted connections under single shear: Test, modelling and design

This paper studies the net-section tensile behaviour of double-sided stainless-clad steel (DSSCS) bolted connections subjected to single shear. The DSSCS composite comprises 304 austenitic stainless-steel cladding layers on both sides and a Q355 low-alloy structural steel substrate in the middle. Both experimental tests and finite element analysis (FEA) were conducted to characterise the failure modes and the load-deflection responses of DSSCS bolted connections. Results demonstrated that all specimens failed by net-section fracture together with the steel plate out-of-plane deformation. Apart from several connections with a relatively large edge distance, the other connections could successfully attain their theoretical tensile resistances, without interfacial delamination observed between the cladding and substrate throughout the test process. On the basis of FEA, tensile stress distributions across the critical net section and along the steel plate thickness were visualised and compared to reproduce the development of stress redistribution and assess the effect on the ultimate tensile resistance. Subsequently, a comprehensive parametric study was carried out to study the influence of the connection edge distance, gauge distance, and the pitch distance on the net-section tensile behaviour. Finally, based on the dataset acquired from experimental tests and FEA, the applicability of current design specifications was assessed. The findings confirm that the formulations codified in EN 1993–1–1: 2022 and AISC 360–22 can provide accurate tensile capacity predictions for DSSCS bolted connections under single shear.