PSI - Issue 54

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 54 (2024) 75–82

© 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 the scientific committee of the ICSI 2023 organizers Abstract Compacted graphite iron (CGI), also known as vermicular graphite iron , is a double-phase engineering material, extensively used in engine cylinders and brake disks, thanks to its good combination of mechanical properties and thermal conductivity. Despite its wide use and considerable past research, the fracture behaviour of CGI at the microscale is not yet fully understood, especially the effect of graphite inclusions. Due to the complex shapes of graphite inclusions randomly embedded in the metallic matrix, development of realistic 3D models is time-consuming and computationally expensive. Hence, a novel 2D computational framework capable of predicting crack initiation and growth in CGI is necessary. In this work, a 2D CZE-based model is developed to predict crack initiation and propagation under different boundary conditions. Scanning electron microscopy was used to characterise the microstructure of CGI, with the resulting scans analysed using image-processing software. The metallic matrix and graphite particles were assumed isotropic and ductile. Cohesive elements were implemented into the models using a Python script and assigned to the ferritic matrix, graphite inclusions, and the graphite-ferrite interface. It was found that employing periodic boundary conditions increased the stiffness of CGI and accelerated interface debonding but prevented crack propagation to the matrix. The developed models will contribute to the understanding of CGI’s fracture behaviour. © 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 the scientific committee of the ICSI 2023 organizers Keywords: CGI; crack initiation; CZE; microstructure; graphite inclusion Nomenclature Fracture energy Cohesive normal traction International Conference on Structural Integrity 2023 (ICSI 2023) Microstructural CZE-based computational model for predicting tensile fracture behaviour of CGI Xingling Luo, Konstantinos P. Baxevanakis 0F *, Vadim V. Silberschmidt Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, LE11 3TU, UK Abstract Compacted graphite iron (CGI), also known as vermicular graphite iron , is a double-phase engineering material, extensively used in engine cylinders and brake disks, thanks to its good combination of mechanical properties and thermal conductivity. Despite its wide use and considerable past research, the fracture behaviour of CGI at the microscale is not yet fully understood, especially the effect of graphite inclusions. Due to the complex shapes of graphite inclusions randomly embedded in the metallic matrix, development of realistic 3D models is time-consuming and computationally expensive. Hence, a novel 2D computational framework capable of predicting crack initiation and growth in CGI is necessary. In this work, a 2D CZE-based model is developed to predict crack initiation and propagation under different boundary conditions. Scanning electron microscopy was used to characterise the microstructure of CGI, with the resulting scans analysed using image-processing software. The metallic matrix and graphite particles were assumed isotropic and ductile. Cohesive elements were implemented into the models using a Python script and assigned to the ferritic matrix, graphite inclusions, and the graphite-ferrite interface. It was found that employing periodic boundary conditions increased the stiffness of CGI and accelerated interface debonding but prevented crack propagation to the matrix. The developed models will contribute to the understanding of CGI’s fracture behaviour. © 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 the scientific committee of the ICSI 2023 organizers Keywords: CGI; crack initiation; CZE; microstructure; graphite inclusion Nomenclature Fracture energy Cohesive normal traction International Conference on Structural Integrity 2023 (ICSI 2023) Microstructural CZE-based computational model for predicting tensile fracture behaviour of CGI Xingling Luo, Konstantinos P. Baxevanakis 0F *, Vadim V. Silberschmidt Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, LE11 3TU, UK

* Corresponding author. Tel.: +44(0) 1509 227030. E-mail address: K.Baxevanakis@lboro.ac.uk * Corresponding author. Tel.: +44(0) 1509 227030. E-mail address: K.Baxevanakis@lboro.ac.uk

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 the scientific committee of the ICSI 2023 organizers 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 the scientific committee of the ICSI 2023 organizers

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 the scientific committee of the ICSI 2023 organizers 10.1016/j.prostr.2024.01.058