Structural Response of Wire Arc Additively Manufactured Steel Bolted Connections under Single Shear

Abstract

An experimental investigation into the structural performance of wire arc additively manufactured (WAAM) steel single-lap shear bolted connections is presented in this paper. Sixty specimens of different thicknesses, printing strategies and geometric features, including end distances and plate widths, were manufactured using steel wire of a nominal yield strength of 420 MPa and subjected to single shear lap tests. The test results are analysed while the observed failure modes, featuring shear-out, net section tension fracture, end-splitting, localised tearing and curl-bearing failure, are discussed. Digital image correlation (DIC) was used for detailed monitoring and visualisation of the surface strain fields that developed during testing, providing valuable insight into the developed failure mechanisms. The experimental results, which generally followed the anticipated trends, were used to assess the applicability of current design specifications developed for conventional steel bolted connections to WAAM steel bolted connections. It was found that both the cold-formed steel specifications (AISI S100 and AS/NZS 4600) and the structural steel specifications (AISC 360 and EN 1993-1) yield considerable overestimations or underestimations of the test capacities, depending on the specimen geometry. Further research is underway to underpin the development of improved design provisions.