Structural behaviour and design of wire arc additively manufactured bolted connections with thick plates

The application of additive manufacturing technology in the construction industry is currently a popular topic around the world. However, the research on the structural behaviour of thick plates produced via Wire and Arc Additive Manufacturing (WAAM) technology has been limited, despite the demand for such components in large-scale constructions that is subjected to large actions. This paper investigated the structural behaviour and design of WAAM single-shear bolted connections with thick plates with failure modes of net section, tilt-bearing, and end-splitting failure. The mechanical properties of the material were first determined by means of tensile coupon tests. An experimental programme of 32 sets of bolted connections with varying dimensions and print layer orientations was conducted. An anisotropic behaviour of WAAM steel bolted connections with different print layer orientations was observed, which had an influence on their failure modes and ultimate capacities. The experimental results were analysed and compared to the predictions using existing design approaches corresponding to conventional steel bolted connections. The comparison showed that these approaches were applicable to WAAM steel bolted connections, but there were still some limitations in the existing design guidelines. This research can contribute to the application of 3D printing technology in constructions.