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Fatigue crack growth model incorporating surface waviness for Wire+Arc additively manufactured components

Boekbijdrage - Boekhoofdstuk Conferentiebijdrage

Ondertitel:Fatigue crack growth model incorporating surface waviness for Wire plus Arc additively manufactured components
Wire+Arc additive manufacturing, due to its high deposition rate, is particularly suited for the construction and repair of large-scale components. For the very same reason, however, an important drawback of this process is the pronounced surface waviness. This waviness introduces multiple adjacent peaks and valleys at the component surface, acting as stress concentration sites which can undermine the fatigue performance. In the present work, the authors propose a framework to model fatigue crack propagation considering the effect of waviness at the component surface. The growth model takes the stress concentration factor as input and incorporates it in a two-fold crack propagation model of a planar flaw. The fracture mechanics based growth models are developed based on El HaddadU+2019s short crack model and the Paris equation for long crack propagation. The effects of stress concentration sites are firstly considered by modifying the short crack propagation parameters. Secondly by introducing a new crack length dependent stress intensity factor threshold, surface waviness is incorporated in the transition from short crack into long crack regime. The results show that short cracks originating from an as-built WAAM surface grow faster as compared to their counterparts originating from machined surfaces.
Volume: 28
Pagina's: 1846 - 1855
Jaar van publicatie:2020