PSI - Issue 61

ScienceDirect Structural Integrity Procedia 00 (2023) 000 – 000 Structural Integrity Procedia 00 (2023) 000 – 000 Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Available online at www.sciencedirect.com ScienceDirect

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

Procedia Structural Integrity 61 (2024) 115–121

© 2024 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 IWPDF 2023 Chairman Abstract Fracture and collapse of granular materials may be observed in a variety of science and engineering applications, including earthquake-induced slope failures, debris flows, as well as controlled surface fracturing of asteroids due to impact loads given during sample-return spacecraft missions. However, the mechanical properties of granular materials, in particular, granular fracture dynamics, have not been completely understood yet. So far, using the experimental technique of dynamic photoelasticity in conjunction with high-speed video cameras, we have recorded dynamic stress transfer and wave / fracture development in two dimensional granular media. Each granular medium, made of penny-shaped birefringent polycarbonate particles, has been placed on a rigid horizontal plane with some inclination (slope) angle and subjected to a single dynamic impact load on its top free surface. From the experimentally recorded transient particle motion and dynamic stress development, we have found two distinct failure patterns. In addition, we have examined the buckling phenomena of granular media and evaluated the effect of confinement and material heterogeneities on granular dynamics through experimental photoelastic observations and numerical discrete element simulations. In this contribution, we further conduct laboratory photoelastic experiments and study the dynamic interaction of particle motion induced by multiple impact loads. We show how transient particle motion, stress transfer and failure patterns inside a granular medium can change according to the variation of the dynamic loading conditions. © 2024 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 IWPDF 2023 Keywords: Stress transfer in granular media; Granular collapse; Granular buckling Abstract Fracture and collapse of granular materials may be observed in a variety of science and engineering applications, including earthquake-induced slope failures, debris flows, as well as controlled surface fracturing of asteroids due to impact loads given during sample-return spacecraft missions. However, the mechanical properties of granular materials, in particular, granular fracture dynamics, have not been completely understood yet. So far, using the experimental technique of dynamic photoelasticity in conjunction with high-speed video cameras, we have recorded dynamic stress transfer and wave / fracture development in two dimensional granular media. Each granular medium, made of penny-shaped birefringent polycarbonate particles, has been placed on a rigid horizontal plane with some inclination (slope) angle and subjected to a single dynamic impact load on its top free surface. From the experimentally recorded transient particle motion and dynamic stress development, we have found two distinct failure patterns. In addition, we have examined the buckling phenomena of granular media and evaluated the effect of confinement and material heterogeneities on granular dynamics through experimental photoelastic observations and numerical discrete element simulations. In this contribution, we further conduct laboratory photoelastic experiments and study the dynamic interaction of particle motion induced by multiple impact loads. We show how transient particle motion, stress transfer and failure patterns inside a granular medium can change according to the variation of the dynamic loading conditions. © 2024 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 IWPDF 2023 Keywords: Stress transfer in granular media; Granular collapse; Granular buckling 3rd International Workshop on Plasticity, Damage and Fracture of Engineering Materials (IWPDF 2023) On the dynamics of a granular medium subjected to multiple impact loads Koji Uenishi a,b, *, Yuichi Kato b 3rd International Workshop on Plasticity, Damage and Fracture of Engineering Materials (IWPDF 2023) On the dynamics of a granular medium subjected to multiple impact loads Koji Uenishi a,b, *, Yuichi Kato b a Department of Advanced Energy, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, 277-8561 Chiba, Japan b Department of Aeronautics and Astronautics, The University of Tokyo, 7-3-1 Hongo, Bunkyo, 113-8656 Tokyo, Japan a Department of Advanced Energy, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, 277-8561 Chiba, Japan b Department of Aeronautics and Astronautics, The University of Tokyo, 7-3-1 Hongo, Bunkyo, 113-8656 Tokyo, 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 © 2024 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 IWPDF 2023 2452-3216 © 2024 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 IWPDF 2023

2452-3216 © 2024 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 IWPDF 2023 Chairman 10.1016/j.prostr.2024.06.016