PSI - Issue 42

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

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Procedia Structural Integrity 42 (2022) 224–235

© 2022 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 23 European Conference on Fracture – ECF23 Abstract The integrity assessment to evaluate the safety margin of reactor pressure vessels (RPV) often considers only the crack initiation and excludes the crack propagation analysis. This contribution focuses on crack propagation analysis in RPV steels. The eXtended Finite Element (XFEM) method implemented in ABAQUS is applied to a thick-walled cylindrical specimen with a circumferential crack at the inner surface in order to simulate crack propagation in embrittled RPV subjected to Pressurized Thermal Shock (PTS). The thick-walled cylinder considered in this study was tested in the FALSIRE project, which results reported the crack opening displacement (COD) and the crack-arrest cycles occurring during the cooling down process. In order to simulate the cylinder with the XFEM, a reduced three-dimensional finite element (FE) model of a small sector (a slice of the cylinder) is used by applying cyclic symmetry boundary conditions. The COD evolution during the PTS transient is calculated and compared against the experimental COD. In the experiment, the COD shows several initiation-arrest-re-initiation cycles and final arrest. However, the results from the simulation show a smooth continuous increase of the COD indicating a progressive crack growth. © 2020 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 23 European Conference on Fracture - ECF23 Keywords: Thermal shock; crack propagation; thick-walled cylinder; xfem 23 European Conference on Fracture - ECF23 Simulation of crack propagation in a thick-walled cylinder using XFEM Diego F. Mora a *, Markus Niffenegger a , Gaojun Mao a a Paul Scherrer Institiute, Nuclear Energy and Safety Department, Structural Integrity Group, CH-5232 Villigen PSI, Switzerland

1. Introduction For a safe operation of nuclear power plants, the integrity of their reactor pressure vessel (RPV) under loss of coolant

* Corresponding author. Tel.: +41-56-3104364. E-mail address: diego.mora@psi.ch.

2452-3216 © 2020 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 23 European Conference on Fracture - ECF23

2452-3216 © 2022 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 23 European Conference on Fracture – ECF23 10.1016/j.prostr.2022.12.028