PSI - Issue 47

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

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Procedia Structural Integrity 47 (2023) 488–502

© 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 IGF27 chairpersons Abstract In recent years, important advances in the field of nanotechnology have demonstrated that using a proper percentage of dispersed nanomaterials inside concrete elements allows their strength and toughness to be significantly improved. This study aims to present a novel methodology for predicting crack propagation phenomena in Ultra-High-Performance Fiber-Reinforced Concrete (UHPFRC) structures enhanced with embedded nanomaterials. The proposed numerical strategy combines a Moving Mesh (MM) technique, based on the well-established Arbitrary Lagrangian-Eulerian formulation, and an Interaction Integral ( i.e. , the M integral) method, both implemented in a finite element framework. The MM is used for tracking the crack advance-related variations in the geometry of the given computation domain, while the M -integral is adopted to extract the Mixed-Mode Stress Intensity Factors (SIFs) at the moving crack front. The mesh is moved according to a maximum principal stress-based fracture criterion. In addition, the proposed strategy incorporates a mesh regularization technique able to ensure the consistency of the mesh points’ motion, thus avoiding excessive mesh distortions. By virtue of this feature, the overall number of remeshing events is drastically reduced. Another novelty aspect of this work is the adoption of an R -Curve approach to accurately capture the quasi-brittle fracture behavior of UHPFRC members enhanced with nano-fillers, even though in the setting of Linear Elastic Fracture Mechanics (LEFM). Comparisons with experimental data reported in the literature are developed to assess the reliability and efficacy of the proposed methodology. © 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 IGF27 chairpersons Abstract In recent years, important advances in the field of nanotechnology have demonstrated that using a proper percentage of dispersed nanomaterials inside concrete elements allows their strength and toughness to be significantly improved. This study aims to present a novel methodology for predicting crack propagation phenomena in Ultra-High-Performance Fiber-Reinforced Concrete (UHPFRC) structures enhanced with embedded nanomaterials. The proposed numerical strategy combines a Moving Mesh (MM) technique, based on the well-established Arbitrary Lagrangian-Eulerian formulation, and an Interaction Integral ( i.e. , the M integral) method, both implemented in a finite element framework. The MM is used for tracking the crack advance-related variations in the geometry of the given computation domain, while the M -integral is adopted to extract the Mixed-Mode Stress Intensity Factors (SIFs) at the moving crack front. The mesh is moved according to a maximum principal stress-based fracture criterion. In addition, the proposed strategy incorporates a mesh regularization technique able to ensure the consistency of the mesh points’ motion, thus avoiding excessive mesh distortions. By virtue of this feature, the overall number of remeshing events is drastically reduced. Another novelty aspect of this work is the adoption of an R -Curve approach to accurately capture the quasi-brittle fracture behavior of UHPFRC members enhanced with nano-fillers, even though in the setting of Linear Elastic Fracture Mechanics (LEFM). Comparisons with experimental data reported in the literature are developed to assess the reliability and efficacy of the proposed methodology. © 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 IGF27 chairpersons 27th International Conference on Fracture and Structural Integrity (IGF27) A moving mesh-based numerical investigation of the failure response of nano-filled ultra-high-performance concrete structures Domenico Ammendolea a , Fabrizio Greco a , Lorenzo Leonetti a , Paolo Lonetti a *, Arturo Pascuzzo a , Rosa Penna b 27th International Conference on Fracture and Structural Integrity (IGF27) A moving mesh-based numerical investigation of the failure response of nano-filled ultra-high-performance concrete structures Domenico Ammendolea a , Fabrizio Greco a , Lorenzo Leonetti a , Paolo Lonetti a *, Arturo Pascuzzo a , Rosa Penna b a Department of Civil Engineering, University of Calabria, Via P. Bucci, Cubo 39B, 87036 Rende (CS), Italy b Department of Civil Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy a Department of Civil Engineering, University of Calabria, Via P. Bucci, Cubo 39B, 87036 Rende (CS), Italy b Department of Civil Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy

* Corresponding author. Tel.: +39 0984 496917. E-mail address: paolo.lonetti@unical.it * Corresponding author. Tel.: +39 0984 496917. E-mail address: paolo.lonetti@unical.it

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 IGF27 chairpersons 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 IGF27 chairpersons

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 IGF27 chairpersons 10.1016/j.prostr.2023.07.075