PSI - Issue 23

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

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Procedia Structural Integrity 23 (2019) 348–353

© 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 scientific committee of the ICMSMF organizers © 201 9 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 scientific committee of the IC MSMF organizers. Polycarbonate is one of th mo promisi g p lymer having potential application as structural materials owi g to its prominent properti s including lightness, strength and toughness. While c mputer- ided de ign of polym r-based engineering products is demanded, obtaining reliable constitutive relations of deformation and fracture has b e a ch llenge. In this study we performed coarse-grained molecular dynamics (CGMD) simulations of polyc bonate to acquire understanding of d formation and fracture mecha i m a the molecular level and estimate yield stress under various loading modes. Inter-particle inte ctions for the CGMD wa constr cted based on all-atom MD usi g the COMPASS model, where molecular structures under strain were included. By tensile simulations of f ur types of loading, namely uniaxial tress, biaxial str ss, uniaxial strain and isotropic stress, we calculated yield stress as functi n of strain rate. We obtain d two master c rves of yield stress-strain rate relati n; one or the form r tw l ading types and the other for the latter two. The curves can b us d f r various tempe atures by proper shift factors. We also found the effec of molar m ss on stress-strain curves; i.e. the larger the molar mass is the larger stress can be attained after yielding, suggesting brittle-ductile transition with increasing molar mass. © 201 9 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommon org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of the IC MSMF organizers. 9th International Conference on Materials Structure and Micromechanics of Fracture Coarse-grained molecular dynamics simulation of deformation and fracture in polycarbonate: Effect of loading mode, strain rate, temperature and molar mass Yoshitaka Umeno a,* , Atsushi Kubo a , Jan-Michael a Albina* a Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505, Japan Polycarbonate is one of the most promising polymers having potential application as structural materials owing to its prominent properties including lightness, strength and toughness. While computer-aided design of polymer-based engineering products is demanded, obtaining reliable constitutive relations of deformation and fracture has been a challenge. In this study we performed coarse-grained molecular dynamics (CGMD) simulations of polycarbonate to acquire understanding of deformation and fracture mechanism at the molecular level and estimate yield stress under various loading modes. Inter-particle interactions for the CGMD was constructed based on all-atom MD using the COMPASS model, where molecular structures under strain were included. By tensile simulations of four types of loading, namely uniaxial stress, biaxial stress, uniaxial strain and isotropic stress, we calculated yield stress as a function of strain rate. We obtained two master curves of yield stress-strain rate relation; one for the former two loading types and the other for the latter two. The curves can be used for various temperatures by proper shift factors. We also found the effect of molar mass on stress-strain curves; i.e. the larger the molar mass is the larger stress can be attained after yielding, suggesting brittle-ductile transition with increasing molar mass. 9th International Conference on Materials Structure and Micromechanics of Fracture Coarse-grained molecular dynamics simulation of deformation and fracture in polycarbonate: Effect of loading mode, strain rate, temperature and molar mass Yoshitaka Umeno a,* , Atsushi Kubo a , Jan-Michael a Albina* a Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505, Japan Abstract Abstract

Keywords: Polycarbonate; Fracture; Multiaxial deformation; Molecular dynamics; Coarse-grained model Keywords: Polycarbonate; Fracture; Multiaxial deformation; Molecular dynamics; Coarse-grained model

* Corresponding author. Tel.: +8-3-5452-6902; fax: +8-3-5452-6120. E-mail address: umeno@iis.u-tokyo.ac.jp * Correspon ing a thor. Tel.: +8-3-5452-6902; fax: +8-3-5452-6120. E-mail address: umeno@iis.u-tokyo.ac.jp

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 scientific committee of the IC MSMF organizers. 2452-3216 © 2019 The Authors. Published by Elsevier B.V. This is an ope acces article under CC BY-NC-ND lic nse (http://creativecommon org/licenses/by-nc-nd/4.0/)

Peer-review under responsibility of the scientific committee of the IC MSMF 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 scientific committee of the ICMSMF organizers 10.1016/j.prostr.2020.01.111