Numerical and Experimental Study on Steel Members Retrofitted by Directed Energy Deposition

authored by: Hamid Dahaghin, Hessam Moshayedi, Niels Pichler, Lingzhen Li, Maryam Mohri, Chenglei Diao, Masoud Motavalli, Seyed Mehdi Zahrai, Elyas Ghafoori
Abstract: Wire and arc additive manufacturing (WAAM) is a versatile technology with applications ranging from manufacturing to the strengthening and repair of aging components. This paper investigates the effectiveness of strengthening techniques using WAAM through both numerical simulations and experimental observations. A thermo-mechanical analysis is employed to predict the temperature and stress fields in repaired specimens. The results show that original cracks in the plate are arrested due to compressive residual stresses generated at the crack tip due to the WAAM process, as well as the increased stiffness around the cracked region. However, new cracks initiate at the edge of the plate/WAAM-material interface which corresponds to the high-stress state in the region. This issue is mitigated significantly by machining the WAAM sample into a pyramid shape, resulting in infinite life for the strengthened plate under fatigue loading. Fractography analysis aids in better understanding the mechanism of sample failure. In conclusion, the results underscore the potential of WAAM repair, offering a hopeful outlook for the future of steel structure maintenance by presenting it as a promising method for mitigating fatigue-induced damage in steel structures.
Organisation(s): Institute of Steel Construction
External Organisation(s): University of Tehran
Swiss Federal Laboratories for Material Science and Technology (EMPA)
ETH Zurich
Hong Kong Polytechnic University
WAAM3D Limited
Type: Conference article
Journal: Procedia Structural Integrity
Volume: 64
Pages: 1192-1199
No. of pages: 8
ISSN: 2452-3216
Publication date: 2024
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Civil and Structural Engineering, General Materials Science, Mechanics of Materials, Mechanical Engineering
Sustainable Development Goals: SDG 3 - Good Health and Well-being
Electronic version(s): https://doi.org/10.1016/j.prostr.2024.09.166 (Access: Open)