1. Experimental characterization and phase-field damage modeling of ductile fracture in AISI 316lVladimir Dunić, Nenad Gubeljak, Miroslav Živković, Vladimir Milovanović, Darko Jagarinec, Nenad Djordjevic, 2024, original scientific article Abstract: ) Modeling and characterization of ductile fracture in metals is still a challenging task in
the field of computational mechanics. Experimental testing offers specific responses in the form of
crack-mouth (CMOD) and crack-tip (CTOD) opening displacement related to applied force or crack
growth. The main aim of this paper is to develop a phase-field-based Finite Element Method (FEM)
implementation for modeling of ductile fracture in stainless steel. (2) A Phase-Field Damage Model
(PFDM) was coupled with von Mises plasticity and a work-densities-based criterion was employed,
with a threshold to propose a new relationship between critical fracture energy and critical total
strain value. In addition, the threshold value of potential internal energy—which controls damage
evolution—is defined from the critical fracture energy. (3) The material properties of AISI 316L steel
are determined by a uniaxial tensile test and the Compact Tension (CT) specimen crack growth test.
The PFDM model is validated against the experimental results obtained in the fracture toughness
characterization test, with the simulation results being within 8% of the experimental measurements.
Keywords: phase-field damage modeling, ductile fracture, crack-tip opening displacement, crack growth, resistance curve, finite element method, simulations
Published in DKUM: 19.09.2024; Views: 0; Downloads: 8
 Full text (3,84 MB)
This document has many files! More... |
2. Introduction to the Computer Simulations : ScriptNejc Novak, Matej Borovinšek, Matej Vesenjak, Zoran Ren, 2024 Abstract: The script entitled „Introduction to the computer simulations“ in the field of Engineering Computer Simulations is intended as a study aid in the lectures of the courses Engineering Computer Simulations for foreign students at the University of Maribor and for students at Kumamoto University, Japan. It explains all the material that students must master in these subjects, and is consistent with the subject curriculum. The basics of computational simulations, based on the Finite Element Method, are given from the theoretical basics to step-by-step preparation of simple computational models and their analysis in PrePoMax software.
Keywords: computational simulations, solid mechanics, Finite Element Method, designing, numerical methods
Published in DKUM: 12.03.2024; Views: 414; Downloads: 41
Full text (7,73 MB)
This document has many files! More... |
3. Dynamic characterisation of novel three-dimensional axisymmetric chiral auxetic structureAnja Mauko, Yunus Emre Yilmaz, Nejc Novak, Tomáš Doktor, Matej Vesenjak, Zoran Ren, 2024, original scientific article Abstract: The study presents an extensive mechanical and computational characterisation of novel cellular metamaterial with axisymmetric chiral structure (ACS) at different strain rates. The Direct Impact Hopkinson Bar (DIHB) testing device was used for impact testing up to 21 m/s striker speed, which was insufficient to reach the shock deformation regime. Thus, using computational simulations to estimate the structure behaviour at high strain rates was necessary. Experimental and computational results showed that all ACS structures exhibit a nominal stress–strain relationship typical for cellular materials. As the loading conditions shifted to a dynamic regime, the micro–inertia effect became increasingly pronounced, leading to a corresponding rise in structure stiffness. The Poisson's ratio in all ACS increases gradually, making them superior to traditional cellular materials, which experience a sudden increase in Poisson's ratio during loading. Additionally, the study found that the structures exhibited a rise in the auxetic effect with an increase in strain rate, highlighting the benefits of axisymmetric structures in high-loading regimes. Overall, the obtained results provide valuable insights into the mechanical properties of ACS under different loading regimes and will contribute to further design improvements and the fabrication of novel ACS metamaterials.
Keywords: axisymmetric chiral structure, auxetic, chiral unit cell, impact testing, dynamic characterisation, finite element simulations
Published in DKUM: 15.02.2024; Views: 345; Downloads: 29
Full text (7,73 MB)
This document has many files! More... |
