PSI - Issue 35

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ScienceDirect

Procedia Structural Integrity 35 (2022) 269–278 Structural Integrity Procedia 00 (2021) 000–000 Structural Integrity Procedia 00 (2021) 000–000

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© 2021 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 IWPDF 2021 Chair, Tuncay Yalçinkaya © 2021 The Authors. Published by Elsevier B.V. his is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) eer-review under responsibility of IWPDF 2021 Chair, Tuncay Yalc¸inkaya. Keywords: Alumina; Ceramic; Surface Profile; Ballistic Performance; SPH; LS-DYNA. Abstract Designers in the defense industry aim to increase the protectiveness of armors while decreasing their weight. On-body armors, composites, and ceramics are widely used due to their lightweight, high hardness, and reduction in blunt trauma. Ceramic armor materials are usually used as the front face for their capability to erode or break up the projectile. There exist various parameters a ff ecting the performance of ceramic armors, and one of these parameters is surface profile. It is a compelling parameter due to its ability to yaw the projectile, causing a reduction of projectile penetration capacity. This study aims to compare alumina ceramic tiles with di ff erent surface profiles in terms of their specific kinetic energy absorption (SKEA). Although experimental results are necessary due to an armor system’s acceptance, numerical results lead to a better understanding of surface profiling. In this study, LS-DYNA software is used for ballistic impact simulations to explore the e ff ect of surface profiling. In the simulations, a steel projectile with varying velocities penetrates a ceramic tile. Johnson-Cook material model is used for the projectile, whereas Johnson- Holmquist material model is used for ceramic tiles. For the modeling of ceramic tile, smoothed particle hydrodynamics (SPH) is used to capture fractures and debris. In this study, the finite element (FE) model that simulates a projectile impacting a flat ceramic tile is generated and validated with the experimental results available in the literature. Then, surface profiled ceramic tiles having spherical surface profile with di ff erent radius values are analyzed, and their SKEA values are compared. It is found that surface profiling can increase the SKEA value up to 56% when the bullet hits the gap between four spheres. The worst ballistic performance of surface profiled tiles occurs when the bullet hits the top of the sphere; however, even the worst performance increases the SKEA value by 21%. © 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review under responsibility of IWPDF 2021 Chair, Tuncay Yalc¸inkaya. Keywords: Alumina; Ceramic; Surface Profile; Ballistic Performance; SPH; LS-DYNA. 2nd International Workshop on Plasticity, Damage and Fracture of Engineering Materials E ff ect of sphere radius and bullet hitting location on the ballistic performance of alumina ceramic tile Deniz C¸ elikbas¸ a, ∗ , Erdem Acar a a Department of Mechanical Engineering, TOBB University of Economics and Technology, 06560 Ankara, Turkey Abstract Designers in the defense industry aim to increase the protectiveness of armors while decreasing their weight. On-body armors, composites, and ceramics are widely used due to their lightweight, high hardness, and reduction in blunt trauma. Ceramic armor materials are usually used as the front face for their capability to erode or break up the projectile. There exist various parameters a ff ecting the performance of ceramic armors, and one of these parameters is surface profile. It is a compelling parameter due to its ability to yaw the projectile, causing a reduction of projectile penetration capacity. This study aims to compare alumina ceramic tiles with di ff erent surface profiles in terms of their specific kinetic energy absorption (SKEA). Although experimental results are necessary due to an armor system’s acceptance, numerical results lead to a better understanding of surface profiling. In this study, LS-DYNA software is used for ballistic impact simulations to explore the e ff ect of surface profiling. In the simulations, a steel projectile with varying velocities penetrates a ceramic tile. Johnson-Cook material model is used for the projectile, whereas Johnson- Holmquist material model is used for ceramic tiles. For the modeling of ceramic tile, smoothed particle hydrodynamics (SPH) is used to capture fractures and debris. In this study, the finite element (FE) model that simulates a projectile impacting a flat ceramic tile is generated and validated with the experimental results available in the literature. Then, surface profiled ceramic tiles having spherical surface profile with di ff erent radius values are analyzed, and their SKEA values are compared. It is found that surface profiling can increase the SKEA value up to 56% when the bullet hits the gap between four spheres. The worst ballistic performance of surface profiled tiles occurs when the bullet hits the top of the sphere; however, even the worst performance increases the SKEA value by 21%. 2nd International Workshop on Plasticity, Damage and Fracture of Engineering Materials E ff ect of sphere radius and bullet hitting location on the ballistic performance of alumina ceramic tile Deniz C¸ elikbas¸ a, ∗ , Erdem Acar a a Department of Mechanical Engineering, TOBB University of Economics and Technology, 06560 Ankara, Turkey

1. Introduction 1. Introduction

Ceramic materials are remarkable components of body armors. For many years metallic-based body armors had been popular, but these armors had become thicker to increase protectiveness. Unfortunately, the thicker plate needs more space, gets heavier, thereby becoming weight ine ffi cient. Compared with metallic-based body armors, ceramic- Ceramic materials are remarkable components of body armors. For many years metallic-based body armors had been popular, but these armors had become thicker to increase protectiveness. Unfortunately, the thicker plate needs more space, gets heavier, thereby becoming weight ine ffi cient. Compared with metallic-based body armors, ceramic-

∗ Corresponding author. E-mail address: d.celikbas@etu.edu.tr (D. C¸ elikbas¸). ∗ Corresponding author. E-mail address: d.celikbas@etu.edu.tr (D. C¸ elikbas¸).

2452-3216 © 2021 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 IWPDF 2021 Chair, Tuncay Yal ç inkaya 10.1016/j.prostr.2022.01.012 2210-7843 © 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review u der responsibility of IWPDF 2021 hair, Tu cay Yalc¸inkaya. 2210-7843 © 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review under responsibility of IWPDF 2021 Chair, Tuncay Yalc¸inkaya.