PSI - Issue 53

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000 ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000

www.elsevier.com/locate/procedia

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 53 (2024) 112–118

© 2023 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 the scientific committee of the ESIAM23 chairpersons Abstract The effect of defects on fatigue performance of AM metals is nowadays the focus of several technical papers, and the Kitagawa-Takahashi diagram is usually employed in order to establish a relationship between fatigue limit and defect size. In such a context, the present paper aims to investigate the defect effect on the fatigue limits of an AM aluminium alloy by exploiting a novel analytical procedure. Such a procedure is based on the joint application of: (i) the Kitagawa-Takahashi diagram, formulated by employing the modified El-Haddad model, for fatigue limit calculations; (ii) the fatigue criterion by Carpinteri et al., based on the critical plane approach, for fatigue strength assessment and lifetime estimation. © 2023 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 the scientific committee of the ESIAM23 chairpersons Keywords: AM metal; defect size; fatigue criterion; Kitagawa-Takahashi diagram 1. Introduction Over the last decade, additive manufacturing (that is, an incremental layer-by-layer production) has become a promising and reliable technique for the production of unique, critical, and geometrically complex metallic components. A large diffusion of Additive Manufactured (AM) components in structural applications under time-varying loading is possible only if safe design procedures are properly developed. In particular, such procedures have to take into account the presence of intrinsic defects (characterising AM metals), which are responsible for a detrimental effect on fatigue strengths. As a matter of fact, these defects represent critical sites where the fatigue crack nucleation is promoted, and are mainly responsible for the lower fatigue properties of AM metals compared to their traditional counterparts (Sanaei and Fatemi (2021)). The main defect characteristics (such as type, size, shape, location) depend on the AM process parameters, that is, scanning strategy and speed, energy input, powder characteristic. As a matter of fact, the trapped gas in the powder material together with an excessive energy are the major sources causing the gas porosities (with a spherical shape); on the other hand, having insufficient energy causes lack of bonding between layers and creates lack of fusion defects (with sharp edges) (Sanaei and Fatemi (2020)). Although AM process parameter optimization, machining and post-processing heat treatments allow to improve fatigue strength of AM metallic components by removing or reducing the intrinsic defects, residual defects that lead to failure still remain. Therefore, the effect of defects on fatigue performance of AM metals is nowadays the focus of several papers, such as research Third European Conference on the Structural Integrity of Additively Manufactures Materials (ESIAM23) A novel procedure for the fatigue behaviour assessment of AM metals with defects Camilla Ronchei*, Andrea Carpinteri, Daniela Scorza, Andrea Zanichelli, Sabrina Vantadori Department of Engineering and Architecture, University of Parma,Parco Area delle Scienze 181/A, 43124 Parma, Italy Abstract The effect of defects on fatigue performance of AM metals is nowadays the focus of several technical papers, and the Kitagawa-Takahashi diagram is usually employed in order to establish a relationship between fatigue limit and defect size. In such a context, the present paper aims to investigate the defect effect on the fatigue limits of an AM aluminium alloy by exploiting a novel analytical procedure. Such a procedure is based on the joint application of: (i) the Kitagawa-Takahashi diagram, formulated by employing the modified El-Haddad model, for fatigue limit calculations; (ii) the fatigue criterion by Carpinteri et al., based on the critical plane approach, for fatigue strength assessment and lifetime estimation. © 2023 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 the scientific committee of the ESIAM23 chairpersons Keywords: AM metal; defect size; fatigue criterion; Kitagawa-Takahashi diagram 1. Introduction Over the last decade, additive manufacturing (that is, an incremental layer-by-layer production) has become a promising and reliable technique for the production of unique, critical, and geometrically complex metallic components. A large diffusion of Additive Manufactured (AM) components in structural applications under time-varying loading is possible only if safe design procedures are properly developed. In particular, such procedures have to take into account the presence of intrinsic defects (characterising AM metals), which are responsible for a detrimental effect on fatigue strengths. As a matter of fact, these defects represent critical sites where the fatigue crack nucleation is promoted, and are mainly responsible for the lower fatigue properties of AM metals compared to their traditional counterparts (Sanaei and Fatemi (2021)). The main defect characteristics (such as type, size, shape, location) depend on the AM process parameters, that is, scanning strategy and speed, energy input, powder characteristic. As a matter of fact, the trapped gas in the powder material together with an excessive energy are the major sources causing the gas porosities (with a spherical shape); on the other hand, having insufficient energy causes lack of bonding between layers and creates lack of fusion defects (with sharp edges) (Sanaei and Fatemi (2020)). Although AM process parameter optimization, machining and post-processing heat treatments allow to improve fatigue strength of AM metallic components by removing or reducing the intrinsic defects, residual defects that lead to failure still remain. Therefore, the effect of defects on fatigue performance of AM metals is nowadays the focus of several papers, such as research Third European Conference on the Structural Integrity of Additively Manufactures Materials (ESIAM23) A novel procedure for the fatigue behaviour assessment of AM metals with defects Camilla Ronchei*, Andrea Carpinteri, Daniela Scorza, Andrea Zanichelli, Sabrina Vantadori Department of Engineering and Architecture, University of Parma,Parco Area delle Scienze 181/A, 43124 Parma, Italy

* Corresponding author. Tel.: +39-0521-905923 E-mail address: camilla.ronchei@unipr.it * Corresponding author. Tel.: +39-0521-905923 E-mail address: camilla.ronchei@unipr.it

2452-3216 © 2023 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 the scientific committee of the ESIAM23 chairpersons 10.1016/j.prostr.2024.01.014 2452-3216 © 2023 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 the scientific committee of the ESIAM23 chairpersons 2452-3216 © 2023 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 the scientific committee of the ESIAM23 chairpersons

Made with FlippingBook Ebook Creator