PSI - Issue 40

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

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

Procedia Structural Integrity 40 (2022) 7–11

© 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 the15th International Conference on Mechanics, Resources and Diagnostics of Materials and Structures. Abstract The problem of computational determination of the effective Poisson's ratio for a mechanical metamaterial having a tetrachiral structure is considered. The problem is solved numerically in the three-dimensional formulation based on the finite element method. The problem is that during uniaxial loading of the sample made of the considered metamaterial it is twisted. This makes it difficult to determine the transverse strain. For observation, 80 fixed points located on the ribs evenly along the length of the sample were selected. When looking at the four equidistant fixed points, it can be found that the deviations in the X-axis and Z axes are commensurate. This indicates that the distance between the points on the straight line perpendicular to the axis of loading does not change, so there is no transverse deformation. From this, it was concluded that the value of the effective Poisson's ratio is zero. The zero value can be explained by the fact that there are transverse elements in the structure. During longitudinal compression, the transverse edges do not twist, which could lead to a contraction in the cross-section of the rod. © 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 the15th International Conference on Mechanics, Resource and Diagnostics of Materials and Structures. Keywords: mechanical metamaterial; chirality; twist; effective properties; numerical simulation. 15th International Conference on Mechanics, Resource and Diagnostics of Materials and Structur Effective Poisson's ratio of tetrachiral mechanical metamaterial L.R. Akhmetshin a,b * a Institute of Strength Physics and Materials Science of Siberian Branch of Russian Academy of Sciences, 2/4 Akademicheskii pr., Tomsk, 634055, Russia b Tomsk State University, 36 Lenin ave., Tomsk, 634050, Russia Abstract The problem of computational determination of the effective Poisson's ratio for a mechanical metamaterial having a tetrachiral structure is c nsidered. The proble is s lved numeri ally in the three-dimensional formulation b sed on the finit element method. The probl m is t at during uniaxial loading of the sample mad of th considered metamaterial it is twisted. This akes it difficult to deter ine t e transverse strain. For observation, 80 fixed points l cated on th ribs evenly along the length of the sample were s l cted. When looking at the four equidistant fixed points, it can be found t at the deviations in the X-axis and Z axes are comm nsurate. This indicates that the distance between the points on the straight line perpendicular to the xis of loading d es not ch nge, so there is no transverse deformation. From this, it was concluded that the val e of the effective Poisson's ratio is zero. The zero value can be explained by the fact that there are transverse elements in the structure. During l ngitudin l compression, the transverse edges do not twist, w ich ould lead to a contraction in the cross-section of the rod. © 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 re ponsibility of the scientific committee of t e15th International Confe ence on Mechanics, Resource and Diagnostics of Mat rials and Structur s. Keywords: mechanical metamaterial; chirality; twist; effective properties; numerical simulation. 15th International Conference on Mechanics, Resource and Diagnostics of Materials and Structures Effective Poisson's ratio of tetrachiral mechanical metamaterial L.R. Akhmetshin a,b * a Institute of Strength Physics and Materials Science of Siberian Branch of Russian Academy of Sciences, 2/4 Akademicheskii pr., Tomsk, 634055, Russia b Tomsk State University, 36 Lenin ave., Tomsk, 634050, Russia

* Corresponding author. Tel.: +7-382-228-6876; fax: +7-382-249-2576. E-mail address: akhmetshin.lr@gmail.com * Corresponding author. Tel.: +7-382-228-6876; fax: +7-382-249-2576. E-mail address: akhmetshin.lr@gmail.com

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 the15th International Conference on Mechanics, Resource and Diagnostics of Materials and Structures. 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 the15th International Conference on Mechanics, Resource and Diagnostics of Materials and Structures.

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 the15th International Conference on Mechanics, Resources and Diagnostics

of Materials and Structures. 10.1016/j.prostr.2022.03.157