Episodios

  • Experimental investigation on mechanical behavior of sandwich structures using Digital Image Correlation (DIC)

    Experimental investigation on mechanical behavior of sandwich structures using Digital Image Correlation (DIC)
    Apr 26 2025
    The aim of this work is to investigate the mechanical behavior of sandwich structures when subjected to edgewise and flatwise compression loadings, using 2D Digital Image Correlation (DIC). These structures are made of Glass Fiber Reinforced Polymer (GFRP) skins with polyurethane foam (PU) core. Initially, the mechanical characterization of each component within the sandwich structure is exanimated. Subsequently, flatwise and edgewise compression tests are conducted on the sandwich panels, in accordance with ASTM C365 and ASTM C364 standards, respectively. Different geometries are studied by testing various lengths of sandwich structures exposed to edgewise compression loads. The DIC technique is applied to analyze and comprehend the deformation and failure mechanisms of GFRP skins and sandwich structures. The results of the present study indicate that the flatwise compression test revealed condensation and densification of PU foam, accompanied by microcracks in GFRP skin. On the other hand, the edgewise compression test on sandwich structures with an equal length-to-width ratio identified several distinct failure modes, including skin-core debonding, shear sliding damage of the skin, and localized buckling. This localized buckling was initially observed in the mid-section of the specimens, followed by skin cracking on both sides, which then propagated across the width of the samples. For other geometric configurations of the sandwich structures, the Euler general buckling mode was observed. The results show that the length of samples has a significant effect on the collapse modes of sandwich structures under edgewise compression.
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    7 m
  • Size effect in concrete beams: a numerical investigation based on the size effect law

    Size effect in concrete beams: a numerical investigation based on the size effect law
    Apr 26 2025
    The size effect significantly influences the structural design of concrete elements, particularly when applying fracture mechanics principles. As structural dimensions increase, a significant outcome of the size effect is the decline in both strength and ductility. To characterize concrete fracture behavior, various fracture mechanics models have been proposed, integrating material fracture properties that are unaffected by changes in geometry and size. Bažant’s size effect law explains this phenomenon based on the transition from ductile to brittle failure in geometrically similar specimens. When failure is delayed after crack initiation, the size effect is mainly influenced by the energy released during macro-crack propagation. Conventional experimental studies on this phenomenon have typically utilized two-dimensional geometrically similar specimens, though they are often limited by laboratory constraints. While experimental studies on notched concrete beams under three-point bending (TPB) exist, their size is often restricted due to practical challenges in handling large specimens and also numerical modeling of large-scale fracture simulations remains limited due to high computational requirements. This research proposes an optimized finite element modeling approach to numerically examine the size effect on the fracture characteristics of notched concrete beams subjected to three-point bending (TPB). Beams with depths up to 1000 mm were analyzed using this approach. The numerical findings align well with experimental size-effect data from the literature, exhibiting the expected trends. Furthermore, fitting the results to Bažant’s size effect law demonstrated a strong correlation, validating the accuracy of the proposed numerical model.
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    6 m
  • A simplified nonlinear model for bamboo-reinforced concrete beams based on lumped damage mechanics

    A simplified nonlinear model for bamboo-reinforced concrete beams based on lumped damage mechanics
    Apr 26 2025
    Bamboo’s renewability may justify bamboo-reinforced concrete (BRC) structures. For practical applications, the accurate description of BRC flexural behaviour is paramount. Lumped damage mechanics is an interesting alternative among some possibilities on nonlinear models since it is based on key concepts of classic fracture and damage mechanics. Therefore, this paper presents a novel lumped damage model for BRC beams. The model’s accuracy is tested with experiments found in the technical literature. Regarding the analysed experiments, the proposed model presents well-fitted results. Finally, the proposed model is feasible for practical applications, even considering structural reliability analysis like Monte Carlo, since it is easy to implement and presents low computational effort.
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    7 m
  • The assessment of the severity of local impact on a pro-bionic composite lattice shell by the use of fiber-optic sensors

    The assessment of the severity of local impact on a pro-bionic composite lattice shell by the use of fiber-optic sensors
    Apr 26 2025
    Authors: S.B. Sapozhnikov, E.A. Dubovikov https://www.fracturae.com/index.php/fis/article/view/5392 The size effect significantly influences the structural design of concrete elements, particularly when applying fracture mechanics principles. As structural dimensions increase, a significant outcome of the size effect is the decline in both strength and ductility. To characterize concrete fracture behavior, various fracture mechanics models have been proposed, integrating material fracture properties that are unaffected by changes in geometry and size. Bažant’s size effect law explains this phenomenon based on the transition from ductile to brittle failure in geometrically similar specimens. When failure is delayed after crack initiation, the size effect is mainly influenced by the energy released during macro-crack propagation. Conventional experimental studies on this phenomenon have typically utilized two-dimensional geometrically similar specimens, though they are often limited by laboratory constraints. While experimental studies on notched concrete beams under three-point bending (TPB) exist, their size is often restricted due to practical challenges in handling large specimens and also numerical modeling of large-scale fracture simulations remains limited due to high computational requirements. This research proposes an optimized finite element modeling approach to numerically examine the size effect on the fracture characteristics of notched concrete beams subjected to three-point bending (TPB). Beams with depths up to 1000 mm were analyzed using this approach. The numerical findings align well with experimental size-effect data from the literature, exhibiting the expected trends. Furthermore, fitting the results to Bažant’s size effect law demonstrated a strong correlation, validating the accuracy of the proposed numerical model.
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    7 m
  • Papers published in 2023-2024 on F&SI focused on Additive Manufactured Materials

    Papers published in 2023-2024 on F&SI focused on Additive Manufactured Materials
    Jan 29 2025
    This audio recording presents a discussion of recent research papers on additive manufacturing (3D printing) of materials for various sectors. The conversation highlights the significant advancements in 3D printing, moving beyond simple prototypes to applications in creating stronger, more sustainable materials for diverse uses, such as enhancing PLA plastic with graphene for increased strength, producing eco-friendly car engine parts, and even restoring historical architecture. A key focus is on addressing challenges like residual stress in 3D-printed metal parts and optimising the printing process for consistent results, utilising techniques like the Taguchi method. Finally, the discussion looks towards the future of 3D printing, including the development of novel materials and the integration of artificial intelligence to improve efficiency and sustainability.
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    18 m
  • Issue 70

    Issue 70
    Jan 16 2025
    The TOC is: Exploring the elastocaloric effect of Shape Memory Alloys for innovative biomedical devices: a review Girolamo Costanza, Ilaria Porroni, Maria Elisa Tata Numerical study of the influence of the parameters of statistical distribution of the structural elements’ ultimate strength on deformable bodies’ fracture processes Eugeniia Feklistova, Artur Mugatarov, Valeriy Wildemann Modeling turning performance of Inconel 718 with hybrid nanofluid under MQL using ANN and ANFIS Paresh Kulkarni, Satish Chinchanikar ANSYS implementation of the phase field fracture approach Dmitry Kosov, Andrey Tumanov, Valery Shlyannikov Tool wear evaluation of self-propelled rotary tool and conventional round tool during turning Inconel 718 Satish Chinchanikar, Nitin Motgi Self-similarity of damage-failure transition and the power laws of fatigue crack advance Mikhail Bannikov, Vladimir Oborin, Oleg Naimark Impact of hybrid nanoparticle reinforcements on Mechanical properties of Epoxy-Polylactic Acid (PLA) Composites M. A. Umarfarooq, K. Dileep, A. Srinath, N.R. Banapurmath, Ashok M. Sajjan Predicting Damage in Notched Functionally Graded Materials Plates through extended Finite Element Method based on computational simulations Hakim Siguerdjidjene, Amin Houari, Kouider Madani, Salah Amroune, Mohamed Mokhtari, Barhm Mohamad, Chellil Ahmed, Abdelkrim Merah, Raul Campilho Mechanical Evaluation of Recycled PETG Filament for 3D Printing Liviu Marsavina, Vlad, Sergiu Rubberized reinforced concrete columns under axial and cyclic loading Mohamed Ahmed, Heba A. Mohamed, Hilal. Hassan, Mahmoud Zaghlal An interface-based microscopic model for the failure analysis of masonry structures reinforced with timber retrofit solutions Fabrizio Greco, Lorenzo Leonetti, Paolo Lonetti, Paolo Nevone Blasi, Arturo Pascuzzo, Giacinto Porco Optimization of the internal structure of 3D-printed components for architectural restoration Valentina Tomei, Ernesto Grande, Maura Imbimbo Correlation coefficients of vibration signals and machine learning algorithm for structural damage assessment in beams under moving load Toan Pham Bao, Vien Le-Ngoc Effect of printing process parameters on tensile strength and wear rate of 17-4PH stainless steel deposited using SLM process Priya Sahadevan , Pon Selvan Chithirai, Avinash Lakshmikanthan, Amiya Bhaumik, Agustin Flores Cuautle Elastic-viscoplastic deformation models of salt rocks Alexander Baryakh, Andrey Tsayukov Application of deep learning for technological parameter optimization of laser shock peening of Ti-6Al-4V alloy Mikhail Verezhak, Aleksei Vshivkov, Elena Gachegova, Maria Bartolomei, Alexander Mayer, Sathya Swaroop Introduction and application of a drive-by damage detection methodology for bridges using variational mode decomposition Shahrooz Khalkhali Shandiz, Hamed Khezrzadeh, Saeed Eftekhar Azam Enhancing Generalizability of a Machine Learning Model for Infrared Thermographic Defect Detection by Using 3D Numerical Modeling Vladimir Vavilov, Arsenii Chulkov, Alexey Moskovchenko
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    30 m
  • Revisiting classical concepts of Linear Elastic Fracture Mechanics

    Revisiting classical concepts of Linear Elastic Fracture Mechanics
    Dec 27 2024
    The audio deep dive explores linear elastic fracture mechanics, analyzing how mathematical models predict crack behavior. Key concepts such as the mathematical crack, stress intensity factors (SIFs), and contact stresses are discussed, highlighting how classical models can lead to impossible overlaps. The analysis also includes the effects of material properties, different loading modes, and stress neutralization techniques. The deep dive emphasizes the importance of refined models and damage tolerance in engineering design.
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    34 m
  • ESIAM23: an interview with Jan Torgersen

    ESIAM23: an interview with Jan Torgersen
    Dec 27 2024
    The interview with Yan Torgersen highlights the advantages of additive manufacturing in the energy sector. Torgersen notes that additive manufacturing uses only the material needed for printing, which reduces waste, and this is a significant benefit in the energy sector, where there is often a lot of waste. Additionally, additive manufacturing provides the geometric freedom to design transport paths inside electrochemical or electrical structures. With the advent of electrically conductive micro and nanoscale devices, additive manufacturing is considered a game changer.
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    1 m
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