PSI - Issue 42

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ScienceDirect

Procedia Structural Integrity 42 (2022) 72–79 Structural Integrity Procedia 00 (2019) 000–000 Structural Integrity Procedia 00 (2019) 000–000

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© 2022 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 23 European Conference on Fracture – ECF23 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) P r-revie under responsibility of 23 European Conference on Fracture – ECF23 . Keywords: Fibre-polymer composite material; Additive Manufacturing; Fibre steering; Continuous carbon fibre; Lug parts; Experimental testing Abstract Additive manufacturing (AM) using continuous carbon fibre (CCF) has facilitated the use of carbon fibre reinforced polymers (CFRP) with AM in structural parts. This paper focusses on the static behaviour of AM CCF lugs printed to an optimised fibre lay up and with two di ff erent CCF fibre volume fractions φ , originating from variation of the layer height. Experimental testing using full field surface strain measurement is performed. The part strength, bearing sti ff ness, and shaft sti ff ness values are evaluated. The most significant benefit is gained in part strength, an increase by 61 % with increase in φ from 0.27 to 0.37. The sti ff ness values are increased to a lesser degree. Fracture behaviour is shown to be fibre fracture dominated in the net section, and linear strain increase is reported until failure. These results show the potential of this technology for structural parts, and give the experimental base for strength and sti ff ness design optimisations in AM CCF lugs. © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review under responsibility of 23 European Conference on Fracture – ECF23 . Keywords: Fibre-polymer composite material; Additive Manufacturing; Fibre steering; Continuous carbon fibre; Lug parts; Experimental testing 23 European Conference on Fracture – ECF23 Experimental strength and fracture analysis of additively manufactured continuous carbon fibre reinforced lugs with load-tailored fibre placement Stefan Sieberer a, ∗ , Markus Winklberger a , Chethan Savandaiah b , Christoph Kralovec a , Marin Schagerl a a Institute of Structural Lightweight Design, Johannes Kepler University Linz, Altenberger Str. 69, 4040 Linz, Austria b Kompetenzzentrum Holz GmbH (Wood K Plus), Altenberger Str. 69, 4040 Linz, Austria Abstract Additive manufacturing (AM) using continuous carbon fibre (CCF) has facilitated the use of carbon fibre reinforced polymers (CFRP) with AM in structural parts. This paper focusses on the static behaviour of AM CCF lugs printed to an optimised fibre lay up and with two di ff erent CCF fibre volume fractions φ , originating from variation of the layer height. Experimental testing using full field surface strain measurement is performed. The part strength, bearing sti ff ness, and shaft sti ff ness values are evaluated. The most significant benefit is gained in part strength, an increase by 61 % with increase in φ from 0.27 to 0.37. The sti ff ness values are increased to a lesser degree. Fracture behaviour is shown to be fibre fracture dominated in the net section, and linear strain increase is reported until failure. These results show the potential of this technology for structural parts, and give the experimental base for strength and sti ff ness design optimisations in AM CCF lugs. 23 European Conference on Fracture – ECF23 Experimental strength and fracture analysis of additively manufactured continuous carbon fibre reinforced lugs with load-tailored fibre placement Stefan Sieberer a, ∗ , Markus Winklberger a , Chethan Savandaiah b , Christoph Kralovec a , Marin Schagerl a a Institute of Structural Lightweight Design, Johannes Kepler University Linz, Altenberger Str. 69, 4040 Linz, Austria b Kompetenzzentrum Holz GmbH (Wood K Plus), Altenberger Str. 69, 4040 Linz, Austria

1. Introduction 1. Introduction

Additive Manufacturing (AM) with continuous carbon fibre (CCF) reinforcement has attracted large interest re cently (Li et al. (2022); Tian et al. (2022); van de Werken et al. (2020)), as the freedom of design o ff ered by AM can be extended to load-bearing structures when including high-performance CCF (Azarov et al. (2019); Dickson et al. (2017)). Load introduction has been an important part of composite design, and eye structures are considered amongst the most e ffi cient methods to introduce large loads over a small area (Ai et al. (2021); Schu¨rmann (2007); Zwingmann et al. (2017)). However, manufacturing of the loop structure is laborious and not easily performed with Additive Manufacturing (AM) with continuous carbon fibre (CCF) reinforcement has attracted large interest re cently (Li et al. (2022); Tian et al. (2022); van de Werken et al. (2020)), as the freedom of design o ff ered by AM can be extended to load-bearing structures when including high-performance CCF (Azarov et al. (2019); Dickson et al. (2017)). Load introduction has been an important part of composite design, and eye structures are considered amongst the most e ffi cient methods to introduce large loads over a small area (Ai et al. (2021); Schu¨rmann (2007); Zwingmann et al. (2017)). However, manufacturing of the loop structure is laborious and not easily performed with

∗ Corresponding author. Tel.: + 43-732-2468-6665 ; fax: + 43-732-2468-6662. E-mail address: stefan.sieberer@jku.at ∗ Corresponding author. Tel.: + 43-732-2468-6665 ; fax: + 43-732-2468-6662. E-mail address: stefan.sieberer@jku.at

2452-3216 © 2022 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 23 European Conference on Fracture – ECF23 10.1016/j.prostr.2022.12.008 2210-7843 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review under responsibility of 23 European Conference on Fracture – ECF23 . 2210-7843 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review under responsibility of 23 European Conference on Fracture – ECF23 .