Article
Construction & Building Technology
Brett Williams, Anna Madra, William Heard, Steven Graham, Michael Grotke, Michael Hillman, Xu Nie
Summary: Damage modes in high-strength concrete under complex stress states were studied in this research, with considerations given to triaxial loading and changes in specimen length-to-diameter ratio. While hydrostatic pressures up to 200 MPa were reversible and caused no detectable damage, damage extent was primarily dictated by triaxial deviator stresses. Brittle failure modes produced shear cracks at angles of 25-30 degrees that became more distributed with increased confinement, while ductile failure modes observed pore collapse with residual strengths similar to 30-50% of pristine strengths.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Construction & Building Technology
G. Mazzucco, B. Pomaro, G. Xotta, E. Garbin, C. E. Majorana, N. De Marchi, G. Concheri
Summary: This study proposes a procedure to reconstruct the geometric meso-scale of concrete materials using X-ray CT, and compares the numerical results with uniaxial compression tests. It confirms the need for a meso-scale characterization for predictive simulations of damage evolution in concrete under 3D stress states.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Materials Science, Ceramics
Faheem Muhammed, Tania Lavaggi, Laure Moretti, Suresh Advani, John W. Gillespie
Summary: Carbon-carbon composites (CCCs), as carbon-fiber reinforced materials, exhibit excellent thermomechanical properties under extreme environmental conditions. In order to reduce cost and processing time, a 7-hour pyrolytic schedule was proposed and successfully achieved for a thermoset benzoxazine-derived CCCs through an optimization process. The optimization involved using a multi-stage nth-order kinetics model to limit individual reaction rates and prevent layer separations and fiber rupture during thermal processing. X-Ray 3D Computed Tomography was used to evaluate the modified results post heat treatment, ensuring a fully interconnected porous microstructure with minimal closed void volume. A 1D model was also proposed to predict internal pressure generated during the final ramp, providing upper bounds for the optimization protocol in terms of sample thicknesses and applied ramp rates.
CERAMICS INTERNATIONAL
(2023)
Article
Thermodynamics
Haizhou Liu, Lingtao Mao, Yang Ju, Francois Hild
Summary: In order to investigate the damage development of coal under different loading conditions, in-situ tests in uniaxial and triaxial compression were conducted. Advanced digital volume correlation based on finite element discretization was used to quantify the three-dimensional initial and newborn fractures. The experiments revealed that the damage growth in coal was substantially affected by randomly distributed initial defects, and prior to a macroscopic failure, the coal samples generally experienced pre-existing fracture closure, newborn fracture initiation, interaction and propagation of the two fracture types. The study aimed to gain in-depth insights into the bulk fracture of coal and provide quantitative evidence for further understanding the damage mechanisms from the microscale to the macroscale.
Article
Engineering, Geological
Changbao Jiang, Yang Yang, Wenhui Wei, Minke Duan, Tang Yu
Summary: This study experimentally investigated the mechanical properties and seepage characteristics of raw coal samples in the process of coalbed methane extraction, proposed the change rate of information entropy as a damage characterization parameter, and developed a permeability evolution model under loading and unloading conditions.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2021)
Article
Materials Science, Multidisciplinary
Zhengkai Wu, Shengchuan Wu, Wentao He, Fandong Meng, Long Wang, Feifan Wang, Chuantao Hou, Guoqing Wang
Summary: This paper investigates the tensile and fatigue damage behaviors of arc-welded AA2219 joints. The main factors affecting fatigue damage behavior are discussed based on microstructure observation and fracture analysis. The results reveal the presence of porosity defects in the weld zone and highlight the softening zone of the welded joint.
MATERIALS CHARACTERIZATION
(2023)
Article
Engineering, Chemical
Yang Yang, Changbao Jiang, Xianwei Guo, Shoujian Peng, Jingjing Zhao, Fazhi Yan
Summary: This study conducted a seepage experiment under constant axial stress and tiered cyclic unloading-loading confining pressure, proposing two new damage variables. The results showed that plastic deformations and permeability of coal increased with unloading levels, with a reverse trend when unloading level was large. The experiment also revealed the coexistence of Kaiser effect and Felicity effect, and the relationship between dissipated energy and cycle number shifted from logarithm to linear as unloading levels increased.
Article
Geochemistry & Geophysics
G. Shahin, R. C. Hurley
Summary: This study investigates the deformation behavior of Ottawa sand under different confining pressures using a high-pressure triaxial apparatus and in-situ x-ray tomography. The results show strain-hardening at pressures above 15 MPa and strain-neutral responses at pressures below 15 MPa. Both compacting shear bands and grain breakage were observed at all pressures.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Engineering, Multidisciplinary
Monika Zielinska, Magdalena Rucka
Summary: Condition assessment of concrete structures is a significant challenge in non-destructive testing, and ultrasound tomography allows imaging of cracks and fracture damage in concrete. This study investigates the application of ultrasound transmission tomography in imaging cracks in concrete before and after wedge splitting tests, introducing a novel method of determining wave propagation time. The effectiveness of fracture damage imaging using ultrasound tomography is verified by X-ray micro-computed tomography.
Article
Soil Science
Ceres Perezvargas y Castor, Alfonso Gastelum-Strozzi, Stephane Sammartino, Eric Michel, Jerome Vicente, Blanca Prado
Summary: Wastewater agricultural irrigation is a common practice to combat water scarcity, but it may affect soil structure. This study investigated the long-term effects of wastewater irrigation on soil structure and found that it led to higher organic carbon and nitrogen contents, as well as increased aggregate stability. These findings enhance our understanding of the impacts of wastewater irrigation on soil structure and provide a better assessment of its benefits and risks.
Article
Materials Science, Composites
Jordan French, Chris Dahlkamp, Elliot Befus, Michael W. Czabaj
Summary: This study presents the development of a novel in-situ biaxial test using synchrotron-based X-ray micro-computed tomography to observe deformation and failure in advanced aerospace materials. By conducting experiments on fabric and laminate specimens, it was found that the test allowed measurement of fabric porosity and fiber straightening, as well as the documentation of crack initiation and evolution in the laminate. The new biaxial test provides a new approach to observe deformation and damage in advanced aerospace materials that was not possible with traditional surface-based observations.
COMPOSITES SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Chemical
A. Macente, K. J. Dobson, J. MacDonald, F. B. Wadsworth, J. Vasseur
Summary: This study investigates the precipitation history of an amygdaloidal basalt containing a pore-connecting micro fracture network partially filled by calcite, as an analogue for CO2 mineral trapping. It provides a semi-quantitative technique for defining reservoir potential and quality through time, shedding light on sub-surface flow and storage mechanisms.
TRANSPORT IN POROUS MEDIA
(2022)
Article
Materials Science, Multidisciplinary
Fabien Leonard, Axel Lange, Andreas Kupsch, Bernd Randolf Mueller, Giovanni Bruno
Summary: This study investigates the anisotropy of materials' microstructure and morphology in diesel particulate filter (DPF) materials, quantifies the morphological anisotropy using a simple segmentation algorithm, and correlates the anisotropy of the pore space with the microstructure and crystallographic anisotropy of the material.
ADVANCED ENGINEERING MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Ercan Cakmak, Philip Bingham, Ross W. Cunningham, Anthony D. Rollett, Xianghui Xiao, Ryan R. Dehoff
Summary: This study focuses on the non-destructive characterization of additively manufactured parts using x-ray computed tomography. It compares laboratory XCT and synchrotron-based XCT, concluding that laboratory XCT is a compelling alternative for static defect characterization in AM parts, while synchrotron-based techniques offer unmatched performance for dynamic and sub-micron studies.
MATERIALS CHARACTERIZATION
(2021)
Article
Construction & Building Technology
Nadezhda Morozova, Kazuma Shibano, Yuma Shimamoto, Sena Tayfur, Ninel Alver, Tetsuya Suzuki
Summary: Deterioration of concrete infrastructures occurs due to freezing-thawing processes, leading to defect accumulation and reduction of mechanical properties. This research investigates the relationship between AE release energy trend and CT parameters for damage quantification in concrete. X-ray CT is used for visualizing and extracting internal components, while UPV and resonant frequency methods are employed to determine the dynamic modulus of elasticity. The results show that frost damage can be evaluated by analyzing CT and AE results to characterize the damage degree.
CASE STUDIES IN CONSTRUCTION MATERIALS
(2023)
Article
Engineering, Civil
Z. Kammouna, M. Briffaut, Y. Malecot
EUROPEAN JOURNAL OF ENVIRONMENTAL AND CIVIL ENGINEERING
(2019)
Article
Architecture
E. Fritsch, Y. Sieffert, H. Algusab, S. Grange, P. Garnier, L. Daudeville
INTERNATIONAL JOURNAL OF ARCHITECTURAL HERITAGE
(2019)
Article
Construction & Building Technology
L. Missemer, E. Ouedraogo, Y. Malecot, C. Clergue, D. Rogat
CEMENT AND CONCRETE RESEARCH
(2019)
Article
Mechanics
Olga Stamati, Emmanuel Roubin, Edward Ando, Yann Malecot
Article
Construction & Building Technology
Zainab Kammouna, Matthieu Briffaut, Yann Malecot
ADVANCES IN CIVIL ENGINEERING
(2019)
Article
Chemistry, Multidisciplinary
Abdallah Accary, Yann Malecot, Laurent Daudeville
APPLIED SCIENCES-BASEL
(2019)
Article
Mathematics, Interdisciplinary Applications
Hicham Benniou, Abdallah Accary, Yann Malecot, Matthieu Briffaut, Laurent Daudeville
Summary: The discrete element model proposed in this paper addresses the macroscopic behavior of concrete while taking into account the presence of free water in pores. This new constitutive model considers the influence of saturation ratio on triaxial compressive stresses in concrete structures subjected to severe loading. By introducing a dependency between water saturation ratio and inelastic deformation due to pore closure, the model aims to model cracking and compaction at the interaction level between discrete elements.
COMPUTATIONAL PARTICLE MECHANICS
(2021)
Article
Engineering, Mechanical
J. Baroth, M. Briffaut, D. Vu, Y. Malecot, L. Daudeville
Summary: This paper presents analytical and finite element models for predicting perforation of reinforced concrete slabs under impacts. The finite element simulations and analytical predictions are consistent with experimental tests.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2021)
Article
Chemistry, Physical
Alejandro Ortega Laborin, Emmanuel Roubin, Yann Malecot, Laurent Daudeville
Summary: This paper conducts an in-depth study on the theoretical basis of strong discontinuity methods for local fracture simulations using the Embedded Finite Element Method (E-FEM). A new proposal of strong discontinuity enhancement functions is presented, improving basic kinematic coherence and robustness of E-FEM techniques for fracture simulations. Simulation results demonstrate increased robustness and potential for higher level application of E-FEM techniques.
Article
Construction & Building Technology
A. Ortega, E. Roubin, Y. Malecot, L. Daudeville
Summary: This paper investigates the application of the Embedded Finite Element Method (E-FEM) in the numerical modeling of triaxial fracture processes in non-homogeneous quasi-brittle materials. The E-FEM framework combines weak and strong discontinuities to account for material heterogeneity and represent local fractures. The enriched fracture kinematics of the strong discontinuity allows modeling of all typical fracture modes in three dimensions. The paper reviews previous work using similar enriched finite element frameworks, establishes the theoretical basis of each discontinuity formulation, and presents numerical simulations to evaluate the performance of the combined E-FEM model.
MATERIALS AND STRUCTURES
(2022)
Article
Chemistry, Physical
Shadi Youssef, Abdallah Accary, Christophe Dano, Yann Malecot
Summary: This study investigates the mechanical behavior of siliceous and calcareous sand materials under high stress levels. The results show that particle breakage is enhanced by the presence of water, smaller particles in siliceous sand are more prone to breakage, and calcareous grains exhibit a faster response to axial stress. Testing various soil properties has the potential to better characterize soil fragility.
Article
Computer Science, Interdisciplinary Applications
A. Ortega, E. Roubin, Y. Malecot, L. Daudeville
Summary: This paper analyzes the application of the Embedded Finite Element Method (E-FEM) in simulating local material heterogeneities. It discusses the evolution of weak discontinuity models within the E-FEM framework and establishes a theoretical basis for enhancing weak discontinuities. The paper introduces two enhancement functions and evaluates their performance through numerical simulations.
COMPUTERS & STRUCTURES
(2022)
Article
Mathematics, Interdisciplinary Applications
Abdallah Accary, Hicham Benniou, Yann Malecot, Matthieu Briffaut, Laurent Daudeville
Summary: This paper investigates the influence of saturation ratio on perforation and penetration of concrete by simulating the impact of ogive-nosed steel projectile on plain concrete targets surrounded by steel jackets.
COMPUTATIONAL PARTICLE MECHANICS
(2023)
Article
Construction & Building Technology
Santosh Yadav, Yannick Sieffert, Florent Vieux-Champagne, Laurent Debove, Damien Decret, Yann Malecot, Philippe Garnier
Summary: This paper explains the steps for the preparation and execution of shake table tests and showcases its advantages and applicability.