PSI - Issue 61

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ScienceDirect

Procedia Structural Integrity 61 (2024) 130–137 Structural Integrity Procedia 00 (2024) 000–000 Structural Integrity Procedia 00 (2024) 000–000

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© 2024 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 IWPDF 2023 Chairman Abstract Localizing implicit gradient damage (LIGD) is a gradient extended model which is equipped with a decreasing internal length scale with damage evolution, Poh and Sun (2017). The model is thermodynamically consistent and resolves the well-known problems of conventional implicit gradient damage (CIGD) model such as artificial di ff usion of damage and erroneous predictions of failure initiation and propagation directions. So far, the e ff ectiveness of the model has been demonstrated for two-dimensional quasi brittle and three-dimensional ductile failure predictions with flat fracture surfaces. It is the aim of this contribution to assess the predictive capabilities of the model for three-dimensional quasi-brittle failures with non-planar cracks. To this end, localizing implicit gradient model is embedded within a tetrahedral element formulation and implemented in commercial finite element package Abaqus through user element (UEL) subroutine. Skew notched prismatic torsion test is modeled and capabilities of the model are assessed in terms of reaction force-displacement curves as well as the resulting crack surfaces, Brokenshire (1996), Je ff erson et al. (2004). Comparison of LIGD and CIGD predictions suggest that LIGD is superior to CIGD. Furthermore, as far as capturing the experimental results is concerned, it performs as good as other alternative modeling frameworks, e.g., mixed finite element formulations. © 2024 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 scientific committee of IWPDF 2023. Keywords: Localizing implicit gradient damage; quasi-brittle failure; finite element method; curved cracks; torsion test 3rd International Workshop on Plasticity, Damage and Fracture of Engineering Materials (IWPDF 2023) Localizing Implicit Gradient Damage Based Modelling of Quasi-brittle Failure with Non-planar Crack Bekir Kac¸maz a , ˙Izzet O¨ zdemir a, ∗ a I˙zmir Institute of Technology, Faculty of Engineering, Department of Civil Engineering, 35430, Urla, I˙zmir, Turkey Abstract Localizing implicit gradient damage (LIGD) is a gradient extended model which is equipped with a decreasing internal length scale with damage evolution, Poh and Sun (2017). The model is thermodynamically consistent and resolves the well-known problems of conventional implicit gradient damage (CIGD) model such as artificial di ff usion of damage and erroneous predictions of failure initiation and propagation directions. So far, the e ff ectiveness of the model has been demonstrated for two-dimensional quasi brittle and three-dimensional ductile failure predictions with flat fracture surfaces. It is the aim of this contribution to assess the predictive capabilities of the model for three-dimensional quasi-brittle failures with non-planar cracks. To this end, localizing implicit gradient model is embedded within a tetrahedral element formulation and implemented in commercial finite element package Abaqus through user element (UEL) subroutine. Skew notched prismatic torsion test is modeled and capabilities of the model are assessed in terms of reaction force-displacement curves as well as the resulting crack surfaces, Brokenshire (1996), Je ff erson et al. (2004). Comparison of LIGD and CIGD predictions suggest that LIGD is superior to CIGD. Furthermore, as far as capturing the experimental results is concerned, it performs as good as other alternative modeling frameworks, e.g., mixed finite element formulations. © 2024 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 scientific committee of IWPDF 2023. Keywords: Localizing implicit gradient damage; quasi-brittle failure; finite element method; curved cracks; torsion test 3rd International Workshop on Plasticity, Damage and Fracture of Engineering Materials (IWPDF 2023) Localizing Implicit Gradient Damage Based Modelling of Quasi-brittle Failure with Non-planar Crack Bekir Kac¸maz a , ˙Izzet O¨ zdemir a, ∗ a I˙zmir Institute of Technology, Faculty of Engineering, Department of Civil Engineering, 35430, Urla, I˙zmir, Turkey

1. Introduction 1. Introduction

Failure of structural components made of quasi-brittle materials has been a central theme particularly in civil engineering due to abundant use of such materials e.g., concrete. Typically, a softening stress-strain response followed by complete fracture is observed in quasi-brittle failure. In fact, this characteristic softening is the source of major di ffi culties associated with continuum damage mechanics (CDM) based models of quasi-brittle failure. Failure of structural components made of quasi-brittle materials has been a central theme particularly in civil engineering due to abundant use of such materials e.g., concrete. Typically, a softening stress-strain response followed by complete fracture is observed in quasi-brittle failure. In fact, this characteristic softening is the source of major di ffi culties associated with continuum damage mechanics (CDM) based models of quasi-brittle failure.

∗ Corresponding author. Tel.: + 90-232-750-6810 ; fax: + 90-232-750-6801. E-mail address: izzetozdemir@iyte.edu.tr ∗ Corresponding author. Tel.: + 90-232-750-6810 ; fax: + 90-232-750-6801. E-mail address: izzetozdemir@iyte.edu.tr

2452-3216 © 2024 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 IWPDF 2023 Chairman 10.1016/j.prostr.2024.06.018 2210-7843 © 2024 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 scientific committee of IWPDF 2023. 2210-7843 © 2024 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 scientific committee of IWPDF 2023.