Ghafoori, ElyasDahaghin, HamidDiao, ChengleiPichler, NielsLi, LingzhenDing, JialuoGanguly, SupriyoWilliams, Stewart2023-10-062023-10-062023-09-12Ghafoori E, Dahaghin H, Diao C, et al., (2023) Metal 3D-printing for repair of steel structures. In: 10th Eurosteel Conference, 12-14 September 2023, Amsterdam, The Netherlandshttps://doi.org/10.1002/cepa.2285https://dspace.lib.cranfield.ac.uk/handle/1826/20343This work employs an innovative technique, wire arc additive manufacturing (WAAM) which is a type of directed energy deposition, for fatigue strengthening of cracked steel components. Different steel plates with a central crack were tested under high-cycle fatigue loading regime, including a reference plate, a plate repaired by WAAM with as-deposited profile, and a plate repaired by WAAM and subsequently machined to reduce stress concentration factors. Corresponding finite element simulation was conducted to provide a better understanding on the mechanism of WAAM-repair. The existing central crack in the reference plate propagated and led to a rupture after 0.94 million cycles, while those in the two WAAM-repaired plates did not propagate, due to the increased net cross-section and the compressive stresses induced by the depositing process. However, in the second plate, a new crack initiated at the root of WAAM profile as a result of local stress concentration, and the fatigue life reached 2.2 million cycles (2.3 times as the reference plate). The third plate, on the other hand, survived more than 9 million fatigue cycles with no visible degradation, thanks to its smooth machined profile. The findings of this work indicate that WAAM repair shows great potential as a technique to address fatigue-related damages in steel structures.enAttribution 4.0 Internationaldirected energy depositionfatigue strengthening3D-printingcrack arrestfatigue life extensionConference paper