PSI - Issue 52

ScienceDirect Available online at www.sciencedirect.com ScienceDirect Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000 Available online at www.sciencedirect.com Procedia Structural Integrity 52 (2024) 63–71 Structural Integrity Procedia 00 (2022) 000 – 000

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2452-3216 © 2023 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 Professor Ferri Aliabadi 10.1016/j.prostr.2023.12.007 2452-3216 © 2023 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 Professor Ferri Aliabadi 2452-3216 © 2023 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 Professor Ferri Aliabadi © 2023 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 Professor Ferri Aliabadi Abstract This work proposed multi-scale modelling to predict the micromechanical properties of semi-crystalline polymers. Semi-crystalline polymers are usually spherulitic crystal structure, which is, however, not completely radially symmetric. In the initial stage of spherulite growth, its structure is manifested as multilayer wafers with a certain orientation namely sheaf structure. The size and orientation of sheaf structure are affected by various processing parameters. Previous research considered spherulite as completely radially symmetric structures, ignoring the effects of structures anisotropy on mechanical properties. In this work, the microstructure of single spherulite was first modelled with different initial orientations. The crystal plasticity constitutive model together with the Arruda-Boyce model was used to describe the micromechanical behaviors of the crystalline lamellae and amorphous lamellae, respectively. Based on the deformation behaviors of single spherulite, the Voronoi tessellation was then used to characterize the multi-spherulites, the evolution of inhomogeneous plastic deformation and inter-lamellae deformation was observed under tension. Achieving the cross-scale analysis from micro-modeling to meso-modeling. The results shown by this work improve the understanding of the micromechanical properties of semi-crystalline polymers, which, in turn, provides 1. Introduction Spherulites are the dominant microstructure of semi-crystalline polymers, composed of stacked crystalline and amorphous lamellae. The structure of spherulites is complex, the formation of which can be divided into four steps according to the characterization results. The initiation of spherulite is from fiber bundles, which gradually grow to a sheaf structure, as shown in Fig. 1a, and then it further expands to a single spherulite. The single spherulite grows and intersects with adjacent spherulites, generating a multi-spherulite structure, which is similar to a Voronoi diagram, as Abstract This work proposed multi-scale modelling to predict the micromechanical properties of semi-crystalline polymers. Semi-crystalline polymers are usually spherulitic crystal structure, which is, however, not completely radially symmetric. In the initial stage of spherulite growth, its structure is manifested as multilayer wafers with a certain orientation namely sheaf structure. The size and orientation of sheaf structure are affected by various processing parameters. Previous research considered spherulite as completely radially symmetric structures, ignoring the effects of structures anisotropy on mechanical properties. In this work, the microstructure of single spherulite was first modelled with different initial orientations. The crystal plasticity constitutive model together with the Arruda-Boyce model was used to describe the micromechanical behaviors of the crystalline lamellae and amorphous lamellae, respectively. Based on the deformation behaviors of single spherulite, the Voronoi tessellation was then used to characterize the multi-spherulites, the evolution of inhomogeneous plastic deformation and inter-lamellae deformation was observed under tension. Achieving the cross-scale analysis from micro-modeling to meso-modeling. The results shown by this work improve the understanding of the micromechanical properties of semi-crystalline polymers, which, in turn, provides theoretical guides to improve their fracture resistance in manufacturing. Keywords: Spherulite; Microstructure; Micro-mechanics; Semi-crystalline polymers 1. Introduction Spherulites are the dominant microstructure of semi-crystalline polymers, composed of stacked crystalline and amorphous lamellae. The structure of spherulites is complex, the formation of which can be divided into four steps according to the characterization results. The initiation of spherulite is from fiber bundles, which gradually grow to a sheaf structure, as shown in Fig. 1a, and then it further expands to a single spherulite. The single spherulite grows and intersects with adjacent spherulites, generating a multi-spherulite structure, which is similar to a Voronoi diagram, as * Corresponding author. Tel.: +86-18846183389 E-mail address: miaocq@hit.edu.cn (C. Miao); zhoujia2023@sina.com(J. Zhou) Fracture, Damage and Structural Health Monitoring Multi-Scale Modelling And Micromechanical Properties Of Semi Crystalline Polymers Chenxu Jiang a , Jia Zhou b,* , Peng Jiang a , Changqing Miao a,* a National Key Laboratory of Science and Technology on Advanced Composites in Special Environment, Harbin Institute of Technology, Harbin 150001, China. b School of Water Conservancy & Civil Engineering, Northeast Agricultural University, Harbin 150006, China. Fracture, Damage and Structural Health Monitoring Multi-Scale Modelling And Micromechanical Properties Of Semi Crystalline Polymers Chenxu Jiang a , Jia Zhou b,* , Peng Jiang a , Changqing Miao a,* a National Key Laboratory of Science and Technology on Advanced Composites in Special Environment, Harbin Institute of Technology, Harbin 150001, China. b School of Water Conservancy & Civil Engineering, Northeast Agricultural University, Harbin 150006, China. theoretical guides to improve their fracture resistance in manufacturing. Keywords: Spherulite; Microstructure; Micro-mechanics; Semi-crystalline polymers * Corresponding author. Tel.: +86-18846183389 E-mail address: miaocq@hit.edu.cn (C. Miao); zhoujia2023@sina.com(J. Zhou)