PSI - Issue 37

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

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Procedia Structural Integrity 37 (2022) 404–409

© 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 Pedro Miguel Guimaraes Pires Moreira Abstract Compared with the mechanics of continua that has been established well, the mechanical characteristics of granular particles, in particular, the dynamic ones, have not been thoroughly clarified yet. Therefore, in our previous preliminary study, dynamic stress transfer as well as wave and fracture development in granular media has been recorded using the experimental technique of dynamic photoelasticity in conjunction with high-speed cinematography. Penny-shaped particles have been prepared by a digital laser cutter and piled on a rigid horizontal plane to form a model slope with some inclination angle. The two-dimensional slope has been subjected to dynamic impact on its top free surface. From the experimentally recorded particle motion and transient stress evolution, two dissimilar failure patterns have been identified. One is the complete collapse of the slope or mass flow due to unidirectional force-chain-like stress transfer, and the other one is the toppling-type separation of the slope face caused by broadly expanding two-dimensional waves. Whichever occurs seems to be governed by the temporal profile of the energy given by the impact. Here, in order to investigate the effect of confinement and possibly material heterogeneities on granular dynamics, first, experimentally, solid plates are additionally placed on some boundaries of the model slopes. It is found that stress transfer and dynamic motion in the confined granular medium is largely controlled by the additional solid boundaries. Then, in order to numerically confirm the above experimental observations, the open source code ESyS-Particle is employed. The numerical results compare well with the experimental ones if the parameters required for the numerics are carefully and properly selected. © 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 Pedro Miguel Guimaraes Pires Moreira Keywords: Stress transfer in granular media; collapse of granular media; dynamic slope failure ICSI 2021 The 4th International Conference on Structural Integrity The effect of confinement and material heterogeneities on the dynamics of a granular medium subjected to impact loading Koji Uenishi a *, Dongyun Xi a a Department of Advanced Energy, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8561, Japan Abstract Compared with the mechanics of continua that has been established well, the mechanical characteristics of granular particles, in particular, the dynamic ones, have not been thoroughly clarified y t. Therefore, in our previous pr lim nary study, dynami stress tr nsfer s w ll as wave a d fracture dev lopment in granular media has be n recorded using the exp ri ental technique of dynamic photo lasticity in conjunction with high-speed cinematography. Penny-shaped pa ticles have be n prepared by a digital laser cutter and piled on a rigid horizontal plane to form a model slo e with some inclin tion angle. Th two-dimensional slope has be n subject t dynamic impact on its top free surface. From the xperimentally recorded particle motion and tra sie t stress evolution, two dissimilar f ilure patterns have been identifi d. One is the co plete collapse of the slope r mass flow due to unidirectional force-chain-like stress transfer, nd th oth r on is the toppling-ty e separation face caused by broadly expandi g two-dime sional waves. Whichever occurs seems to be g verned b the temporal profile of the en rgy given by the impact. Here, in r er to investig te the effect of c nfinem nt and possibly material he rogeneities on granular dynamics, first, xperimentally, solid pla es ar addi ionally placed on some boundaries of the model slop s. It is found that stress tra sfer and dynamic otion in the confined gr nular medium is largely controlled by the additi nal s lid boundaries. Then, in order to numerically onfirm the above exp rime ta obs rvation , the open sourc code ESyS-Particle is employed. The numerical results compare well with experimental ones if the parameters required fo the numerics are carefully and properly select d. © 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 u der re ponsibility of Pedro Miguel Guimara s Pires Moreira Keywords: Stress transfer in granular media; collapse of granular media; dynamic slope failure ICSI 2021 The 4th International Conference on Structural Integrity The effect of confinement and material heterogeneities on the dynamics of a granular medium subjected to impact loading Koji Uenishi a *, Dongyun Xi a a Department of Advanced Energy, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8561, Japan

* Corresponding author. Tel.: +81-4-7136-3824; fax: +81-4-7136-3824. E-mail address: uenishi@k.u-tokyo.ac.jp * Corresponding author. Tel.: +81-4-7136-3824; fax: +81-4-7136-3824. E-mail address: uenishi@k.u-tokyo.ac.jp

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 Pedro Miguel Guimaraes Pires Moreira 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 Pedro Miguel Guimaraes Pires Moreira

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 Pedro Miguel Guimaraes Pires Moreira 10.1016/j.prostr.2022.01.102