PSI - Issue 47

Panagiotis N. Lymperopoulos et al. / Procedia Structural Integrity 47 (2023) 274–281 Panagiotis N. Lymperopoulos, Efstathios E. Theotokoglou/ Structural Integrity Procedia 00 (2022) 000–000

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Fig. 11. E c for different pentamode heights

According to Figs. 10 and 11, higher values for G c and E c are appeared comparing to previous cases and many discrepancies especially in the case of E c, are also appeared. These discrepancies may result in pentamode failure.

5. Conclusions Pentamodes mechanical metamaterials, are structures designed to confront different loading conditions. They are applied especially to the case of antiseismic design. Harmonical loading conditions are observed to a wide variety of engineering applications. A first study of pentamodes bulk and shear strength behaviour is essential for pentamodes evaluation. In this study, a first evaluation of pentamodes bulk and shear strength behaviour has been carried out. According to our study, pentamodes have shear and bulk strength under harmonical loading conditions, close to shear and bulk strength under static loading conditions. In addition, pentamodes with confinement plates appear to have increased shear and bulk strength. Furthermore, it has been observed that pentamodes designed with thinner rods appear to have more discrepancies in the band of 0Hz to 10Hz. These discrepancies may result in pentamode failure. A further study is also requested in order to study the pentamode behaviour under different loading conditions. Acknowledgements This research was funded by the Research Committee of the National Technical University of Athens. References Kadic M., Bueckmann T., Stenger N., Thiel M., Wegener M., On the practicability of pentamode mechanical metamaterials, Applied Physics Letters, 2012, 100, p.p. (191901-1)-(191901-4). Norris N. A., Mechanics of elastic networks. Proceedings of the Royal Society of London A, 2014, 470 (2172). Amendola A. , Carpentieri G. , Feo L. , Fraternali F., Bending dominated response of layered mechanical metamaterials alternating pentamode lattices and confinement plates 2016 Fabbrocino F., Amendola A., Benzoni F., Fraternali F., “Seismic Appilcation of Pentamode Lattices,” International Journal of Earthquake Engineering, 2015, p.p. 62-71. Lymperopoulos P. N., Theotokoglou E. E., Numerical Investigation of Pentamode Mechanical Metamaterials, WSEAS Transactions on Applied and Theoretical Mechanics, vol. 17, pp. 47-55, 2022 Mu D., Shu H., Zhao L., An S., A Review of Research on Seismic Metamaterials Advanced Engineering Materials, 2020, 22 1901148 Ji J C., Luo Q. Ye K., Vibration control based metamaterials and origami structures: A state-of-the-art review Mechanical Systems and Signal Processing, 2021, 161 (107945) Lymperopoulos P. N., Theotokoglou E. E., Antoniadis I. A., Computational analysis of metamaterials - an initial study, Procedia Structural Integrity, 2020, 25, p.p. 172–179 Cushing C. W., Kelsten M. J., Su X., Wilson P. S., Haberman M. R., Norris A. N., Design and characterization of a three-dimensional anisotropic additively manufactured pentamode material, The Journal of the Acoustical Society of America, 2022, 151, p.p. 168–79