Crack propagation in Anisotropic Materials manufactured by Fused Filament Fabrication processes (experiments and modelling) – 3FAM

Due to the directional building process, additive manufacturing generally leads to anisotropic microstructures that highly influence crack propagation paths. It is thus crucial to be able to take this directionality into account in damage tolerance approaches. This is even essential to extend the use of additive manufacturing to sensitive components, for instance, in the field of aeronautics or aerospace where catastrophic failure has to be avoided at all costs. In this project, a first step toward this goal is aimed for in the framework of Linear Elastic Fracture Mechanics, by focusing on Fused Filament Fabrication processes. As general models are sought,
the processes for printing polymers by Fused Deposition Modeling, and metals by Markforged will be considered. State-of-the-art experimental and numerical methods, together with an interdisciplinary mechanics-physics point of view, will be geared toward (i) a deep and multi-scale understanding of the physical phenomena at play, and (ii) the development of safe, experimentally validated, mechanical methods to accurately predict crack propagation from fatigue to brittle fracture threshold. The methodology will involve advanced and innovative tools, notably new fracture experiments carried out in-situ in an XRay scanner, analyzed by Digital Volume Correlation in conjunction with multiscale asymptotic approaches and phase-field simulations. The expected benefits are to provide tools to develop lighter, while safe, additively manufactured components, but also to elaborate damage tolerance approaches applying to a broad range of anisotropic materials, going from 3D printed components to monocrystals in airplane engine components.