PSI - Issue 68

ScienceDirect Structural Integrity Procedia 00 (2025) 000–000 Structural Integrity Procedia 00 (2025) 000–000 Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Available online at www.sciencedirect.com ScienceDirect

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Procedia Structural Integrity 68 (2025) 91–98

European Conference on Fracture 2024 Modelling the evolution of fracture process zone considering strain rate effect Nhan T. Nguyen a , Dat G. Phan a , Ha H. Bui b , Murat Karakus c , Giang D. Nguyen a, * a School of Architecture and Civil Engineering, The University of Adelaide, SA 5005, Australia Abstract This paper highlights the importance of strain rate effects at the meso scale of the Fracture Process Zone (FPZ) on macro responses through a numerical approach employing a new coupled damage-plasticity model for the simulation of a three-point bending test on quasi-brittle materials using the SPH (Smoothed Particle Hydrodynamics). The strain rate effect is handled by enhancing the flow rules with a Perzyna-type rate-dependent formulation. This enhancement improves the capability of the model to describe constitutive behaviour under varying strain rates, with results showing that the rate-dependent formulation can capture the increase in flexural strength at higher loading velocities. While both rate-dependent and rate-independent models lead to comparable strain rates inside the FPZ as applied loading velocity changes, the peak loads vary significantly. This simulation result highlights strong dynamic effects inside the FPZ that can influence the macro response, even in quasi-static loading conditions, encouraging future experimental work to investigate this connection. © 2025 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 ECF24 organizers Keywords: Strain rate; fracture process zone; quasi-brittle material; thermodynamics; damage continuum mechanics; couple damage-plasticity; constitutive modelling European Conference on Fracture 2024 Modelling the evolution of fracture process zone considering strain rate effect Nhan T. Nguyen a , Dat G. Phan a , Ha H. Bui b , Murat Karakus c , Giang D. Nguyen a, * a School of Architecture and Civil Engineering, The University of Adelaide, SA 5005, Australia b Department of Civil Engineering, Monash University, Clayton, VIC 3800, Australia c School of Chemical Engineering, The University of Adelaide, SA 5005, Australia Abstract This paper highlights the importance of strain rate effects at the meso scale of the Fracture Process Zone (FPZ) on macro responses through a numerical approach employing a new coupled damage-plasticity model for the simulation of a three-point bending test on quasi-brittle materials using the SPH (Smoothed Particle Hydrodynamics). The strain rate effect is handled by enhancing the flow rules with a Perzyna-type rate-dependent formulation. This enhancement improves the capability of the model to describe constitutive behaviour under varying strain rates, with results showing that the rate-dependent formulation can capture the increase in flexural strength at higher loading velocities. While both rate-dependent and rate-independent models lead to comparable strain rates inside the FPZ as applied loading velocity changes, the peak loads vary significantly. This simulation result highlights strong dynamic effects inside the FPZ that can influence the macro response, even in quasi-static loading conditions, encouraging future experimental work to investigate this connection. © 2025 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 ECF24 organizers Keywords: Strain rate; fracture process zone; quasi-brittle material; thermodynamics; damage continuum mechanics; couple damage-plasticity; constitutive modelling © 2025 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 ECF24 organizers b Department of Civil Engineering, Monash University, Clayton, VIC 3800, Australia c School of Chemical Engineering, The University of Adelaide, SA 5005, Australia

* Corresponding author. Tel.: +618-8313-2259; fax: +618-8313-4359. E-mail address: g.nguyen@adelaide.edu.au * Corresponding author. Tel.: +618-8313-2259; fax: +618-8313-4359. E-mail address: g.nguyen@adelaide.edu.au

2452-3216 © 2025 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 ECF24 organizers 2452-3216 © 2025 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 ECF24 organizers

2452-3216 © 2025 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 ECF24 organizers 10.1016/j.prostr.2025.06.027