Testing and design of wire and arc additively manufactured steel double-shear bolted connections with thick plates

The integration of additive manufacturing technology into the construction sector has attracted considerable interest in recent years. However, despite the increasing demand for large-scale constructions subjected to large forces, the research on the structural behaviour of thick plates fabricated via Wire and Arc Additive Manufacturing (WAAM) technology has been limited. This paper investigated the structural behaviour and design of WAAM carbon steel double-shear bolted connections with thick plates. The experiment examined 30 bolted connections with varying geometric dimensions and print layer orientations, discovering failure modes including net section tension, shear-out, end-splitting, and bearing failure. The research revealed anisotropic behaviours in WAAM steel bolted connections, with different print layer orientations affecting their failure modes and ultimate capacities. It is consistent with the inherent anisotropy observed in WAAM steel materials. Furthermore, the experimental results were analysed and compared with predictions made by existing design approaches for conventional steel bolted connections. While the existing guidelines were found to be applicable to WAAM steel bolted connections, certain limitations were identified.