PSI - Issue 39

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000–000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 39 (2022) 81–88

© 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of CP 2021 – Guest Editors Abstract In recent years, Additive Manufacturing (AM) emerged as a disruptive technology, able to manufacture complex geometries and features, which are not producible through traditional manufacturing processes. The diffusion of AM has therefore permitted to exploit the advantages of the design based on Topology Optimization (TO) algorithms, which provide the material distribution allowing for maximizing the component stiffness with the minimum mass. In order to guarantee the structural integrity of the designed part, constraints on the maximum allowable stress can be set. If the component is subjected to quasi-static loads, the yield stress is generally considered as the limit stress. In case of fatigue loads, the conventional fatigue limit can be, on the other hand, considered. However, it is well known that the fatigue response of parts produced through AM process is controlled by the manufacturing defects (e.g., porosity, incomplete fusion defects). The influence of defects is generally not considered when components are designed through TO algorithms, even if it drives the structural response. Only recently, a defect-driven TO algorithm, named TopFat, has been developed by the Authors. In the present paper, a methodology based on TO algorithms commercially available for the design against fatigue failures from defects is proposed. The influence of defects and the dependency between the defect size and the component volume is assessed through models available in the literature. The methodology has been applied to design components currently used for aerospace applications. To conclude, this study aims at providing a guideline for safely designing real AM parts considering the presence of defects by means of commercial TO software. © 2021 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) 7th International Conference on Crack Paths Defect-Driven Topology Optimisation: TopFat algorithm validation via 3D components re-design for real industrial applications Riccardo Caivano a, *, Andrea Tridello a , Giovanni Barletta b , Nicola Gallo b , Antonio b Baroni, Filippo Berto c , Davide Paolino a,d a Department of Mechanical and Aerospace Engineering, Politecnico di Torino, 10129 Turin, Italy b Aerostructures Division, Leonardo SPA, 74023 Taranto, Italy c Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology (NTNU), Trondheim, Noray d IMAST S.c.ar.l.—Technological District on Engineering of Polymeric and Composite Materials and Structures, 80133 Napoli, Italy

Peer-review under responsibility of CP 2021 – Guest Editors Keywords: Topology Optimisation; Murakami Fatigue Limit; Defect

* Corresponding author. Tel.: +39 333 262 5290 E-mail address: riccardo.caivano@polito.it

2452-3216 © 2021 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of CP 2021 – Guest Editors

2452-3216 © 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of CP 2021 – Guest Editors 10.1016/j.prostr.2022.03.075