PSI - Issue 21

Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000

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Procedia Structural Integrity 21 (2019) 173–184

1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials Consideration on the toughness difference depending on the direction of brittle crack propagation in very thick steel 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials Considerati n on th toughness difference d pending on the direction of brittle crack propagation in very thick steel

Taiko Aikawa a , Tomoya Kawabata a a Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku Tokyo, 113-8654, Japan Taiko Aikawa a , Tomoya Kawabata a a Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku Tokyo, 113-8654, Japan

© 2019 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 the 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers © 2019 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 the 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers Abst a t In recent years, the steel plates used in large structures such as container ships have become extremely thick, and th ir strength is i creasing. Since the risk of brit le fracture increas s as the s eel pl te thickness increase (T. Ishikawa et al, 2004), it is to roperly stop brittle cracks generated from the viewpoint of ensuring af ty. In the discu sion about fract re safe y of l rg container ships from the viewpoint of arrest in these ten years, two fracture safety scena ios were established. Recently an important experimental fact that he brittle crack stopping toughness K ca is lower in cenario 1 than in scenario 2 was f und, but th cause has not reve led yet. In ord r to clarify the cause of this exp rimental fact, the authors carried out the three-sided slit ed Charpy test and the DWTT test in which the propagation direction of the crack was devised. Parameters such as mis-orientation between neighbour grains and fracture surface roughness were calculated, and the correlation with brittle crack propagation arrest properties was examined. © 2019 The Autho s. Publ shed 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 the 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers 2452-3216 © 2019 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 the 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers 1. Introduction In recent years, container ships for marine transportation have been drastically increasing in size, and steel plates, which are structural members of container ships, have been increasing in strength and thickness (Yamaguchi et al, 2005). Safety design against brittle fracture is very important because the risk of brittle fracture increases as steel plate 2452 3216 © 2019 Th 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 the 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers 1. Introduction In recent years, container ships for marine transportation have been drastically increasing in size, and steel plates, which are structural members of container ships, have been increasing in strength and thickness (Yamaguchi et al, 2005). Safety design against brittle fracture is very important because the risk of brittle fracture increases as steel plate Abstract In recent years, the steel plates used in large structures such as container ships have become extremely thick, and their strength is increasing. Since the risk of brittle fracture increases as the steel plate thickness increases (T. Ishikawa et al, 2004), it is important to properly stop brittle cracks generated from the viewpoint of ensuring safety. In the discussion about fracture safety of large container ships from the viewpoint of arrest in these ten years, two fracture safety scenarios were established. Recently an important experimental fact that the brittle crack stopping toughness K ca is lower in scenario 1 than in scenario 2 was found, but the cause has not revealed yet. In order to clarify the cause of this experimental fact, the authors carried out the three-sided slitted Charpy test and the DWTT test in which the propagation direction of the crack was devised. Parameters such as mis-orientation between neighbour grains and fracture surface roughness were calculated, and the correlation with brittle crack propagation arrest properties was examined. Keywords: Container ship, arrest toughness, twist angle, mis-orientation, DWTT test, brittle crack propagation Keywords: Container ship, arrest toughness, twist angle, mis-orientation, DWTT test, brittle crack propagation

2452-3216 © 2019 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 the 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers 10.1016/j.prostr.2019.12.099