PSI - Issue 24

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

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

Procedia Structural Integrity 24 (2019) 324–336

© 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 AIAS2019 organizers Abstract In this work the failure behavior of ductile cast iron microstructure subjected to tensile and low-cycle fatigue loadings is simulated by a 3-D, FE Reference Volume Element approach. A fully ferritic matrix is considered as representative of the low-hardness, high-ductility material class of nodular cast irons. Plastic flow potential rule, ductile and low cycle fatigue damage models are implemented at the micro-scale for the matrix constituent in conjunction with nonlinear cyclic hardening laws, and periodic boundary conditions are imposed over the RVE at the meso-scale. Different values of triaxiality are imposed. Numerical results confirm experimental findings of the behavior at the meso-scale and correctly predict the LCF lifetime, driving the interpretation of inner strain distribution, voids interaction and triaxiality effects on failure mechanisms. © 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 AIAS2019 organizers AIAS 2019 International Conference on Stress Analysis Microstructure-based RVE modeling of the failure behavior and LCF resistance of ductile cast iron Luca Collini a, *, Alessandro Pirondi a a Department of Engineeri g and Architecture, University of Parma Viale delle Scienze 181/A, 43124 Parma (Italy) Abstract In this work the failure behavior of ductile cast iron microstructure subjected to tensile an low-cycle fatigu loadings is simulated by a 3-D, FE Ref rence Volume Element approach. A fully ferritic m trix is considere as repres nt tive of the low-hardness, high-ductility material lass of nodular cast irons. Plastic flow potential rule, ductile and low cycle fatigue d mage mod ls are implemented at the micro-scal f r the matrix constituent in conjunction with nonline r cyclic hardening laws, and periodic b undary conditions are imposed over t e RVE at the meso-scale. Different values of triaxiality are imposed. Numerical results confirm experimental findings of th behavior at the meso-scale and correctly predict the LCF lifetime, driving the interpretation of inner strain distribution, voids interaction and triaxiality effects on failure mechanisms. © 2019 The Authors. Published by Elsevier B.V. This is an ope access article under t CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the AIAS2019 organizers AIAS 2019 International Conference on Stress Analysis Microstructure-based RVE modeling of the failure behavior and LCF resistance of ductile cast iron Luca Collini a, *, Alessandro Pirondi a a Department of Engineering and Architecture, University of Parma Viale delle Scienze 181/A, 43124 Parma (Italy) 1. Introduction Nodular, or ductile cast iron (DCI), presents the peculiar characteristics of the graphite precipitated in tiny balls or spheroids. Spheroids interrupt the iron matrix much less than graphite flakes, as occurring in gray cast iron, resulting in higher strength and toughness, i.e. ductility. Subsequently its use in widespread for the production of many industrial parts which include crankshafts, gears, rocker arms and disc brake calipers. 1. Introduction Nodular, or ductile cast iron (DCI), presents the peculiar characteristics of the graphite precipitated in tiny balls or spheroids. Spheroids interrupt the iron matrix much less than graphite flakes, as occurring in gray cast iron, resulting in higher strength and toughness, i.e. ductility. Subsequently its use in widespread for the production of many industrial parts which include crankshafts, gears, rocker arms and disc brake calipers. Keywords: Ductile cast iron; RVE; Ductile damage model; Triaxiality; Low-cycle fatigue. Keywords: Ductile cast iron; RVE; Ductile damage model; Triaxiality; Low-cycle fatigue.

* Corresponding author. Tel.: +39-0521-905892; fax: +39-0521-905705. E-mail address: luca.collini@unipr.it * Correspon ing author. Tel.: +39-0521-905892; fax: +39-0521-905705. E-mail address: luca.collini@unipr.it

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 AIAS2019 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://creativecommons.org/licenses/by-nc-nd/4.0/)

Peer-review under responsibility of the AIAS2019 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 AIAS2019 organizers 10.1016/j.prostr.2020.02.030