PSI - Issue 28

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Procedia Structural Integrity 28 (2020) 1148–1159

1st Virtual European Conference on Fracture Fatigue properties of aluminium triangular lattice plates Yifan Li*, Martyn J. Pavier, Harry Coules Department of Mechanical Engineering, University of Bristol, Queens Building, University Walk, Bristol BS8 1TR, UK 1st Virtual European Conference on Fracture Fatigue properties of aluminium triangular lattice plates Yifan Li*, Martyn J. Pavier, Harry Coules Department of Mechanical Engineering, University of Bristol, Queens Building, University Walk, Bristol BS8 1TR, UK

© 2020 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 European Structural Integrity Society (ESIS) ExCo © 2020 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 European Structural Integrity Society (ESIS) ExCo Abstract W propose a metho to predict the fatigue life of triangular ttices by using fat gue data f om tests on single lattice struts. The method was vali ated usin fatigu tests on 6 identical t iangu ar lattice plates divided into three groups with differe t initial cra k len ths. The pr dicted fatigu lives of lattices agree very well with the experimental results. A three-stage mechanism fatigue was obs rved in the tests, and the crack propagated in the direction 30° to the horizontal ax s in the upper half of lattice late in all three groups. The fatigue rack propagation rate was also studied nd calculat d by using the eff ctive mec anical param te s fr m the homoge ized st ucture. Experimental fatigue c ack growth rat data were compared with predictions, showing that the proposed method can also predict the crack growth rate in triangular lattices very well. © 2020 The Authors. Published by ELSEVIER B.V. This is an ope acces article under CC BY-NC-ND license (ht ps:// r ativecommons. rg/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo 1. Introduction Natural cellul r materials su h as wood, b mboo and bone often exhibit sup rior mechanical properties (Yano et al. 1997; Jain et al. 1992). Lattice structures r artificial c llular structures, ofte inspired by nat ral materials, and have attract d incr asing att ntion. These materials ar used in many engineering applications such a lightweight support i erospace industries, heat exchangers and filters, and bone replacements because of their high strength, heat insulation and high porosity (Noor et al. 2000; Heinl et al. 2008). Abstract We propose a method to predict the fatigue life of triangular lattices by using fatigue data from tests on single lattice struts. The method was validated using fatigue tests on 6 identical triangular lattice plates divided into three groups with different initial crack lengths. The predicted fatigue lives of lattices agree very well with the experimental results. A three-stage mechanism of lattice fatigue was observed in the tests, and the crack propagated in the direction 30° to the horizontal axis in the upper half of lattice plate in all three groups. The fatigue crack propagation rate was also studied and calculated by using the effective mechanical parameters from the homogenized structure. Experimental fatigue crack growth rate data were compared with predictions, showing that the proposed method can also predict the crack growth rate in triangular lattices very well. Keywords: triangular lattice plate; single strut; fatigue; crack growth rate Keywords: triangular lattice plate; single strut; fatigue; crack growth rate 1. Introduction Natural cellular materials such as wood, bamboo and bone often exhibit superior mechanical properties (Yano et al. 1997; Jain et al. 1992). Lattice structures are artificial cellular structures, often inspired by natural materials, and have attracted increasing attention. These materials are used in many engineering applications such as lightweight support in aerospace industries, heat exchangers and filters, and bone replacements because of their high strength, heat insulation and high porosity (Noor et al. 2000; Heinl et al. 2008).

* Corresponding author. Tel.: +44 759648 4143; fax: + 44 117929 4423. E-mail address: yifan.li@bristol.ac.uk * Corresponding author. Tel.: +44 759648 4143; fax: + 44 117929 4423. E-mail address: yifan.li@bristol.ac.uk

2452-3216 © 2020 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 European Structural Integrity Society (ESIS) ExCo 2452-3216 © 2020 The Authors. Published by ELSEVIER B.V. This is an ope acces article under CC BY-NC-ND license (ht ps:// r ativecommons. rg/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo

2452-3216 © 2020 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 European Structural Integrity Society (ESIS) ExCo 10.1016/j.prostr.2020.11.096