Article
Green & Sustainable Science & Technology
Yubin Wang, Baojiang Sun, Tianju Wang, Zhiwei Hao, Bo Wang
Summary: This article investigates the simulation model of the aperture of diversion fractures influenced by various factors during hydraulic fracturing. The results show that the aperture of the previous fracture can be enlarged by tight plugging, and increasing the fluid injection rate effectively increases the aperture of the fracture mouth.
Article
Energy & Fuels
C. P. Zhang, P. Cheng, Z. Y. Ma, P. G. Ranjith, J. P. Zhou
Summary: The study compared the fracturing efficiency of CO2-based fracturing (CBF) and water-based fracturing (WBF) on siltstone samples, revealing that CBF has lower breakdown pressure and greater fracture aperture compared to WBF, which helps create more complex and efficient fracture networks.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2021)
Article
Construction & Building Technology
Junlong Du, Xiaosheng Wei, Cong Tian
Summary: In this research, the shrinkage cracking and fracture properties of fiber-reinforced cementitious composites (FRCC) were studied. It was found that increasing the polyvinyl alcohol (PVA) fiber content can effectively reduce crack width, delay cracking time, and enhance fracture toughness and fracture energy. PVA fibers play a crucial role in extending the intermediate stage of cementitious materials and delaying energy release rate during failure.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Engineering, Multidisciplinary
Fang Shi, Daobing Wang, Xiaogang Chen
Summary: The study investigates the behavior and propagation mechanisms of hydraulic fractures in fracture-cavity reservoirs, finding that factors such as lateral stress coefficient, confining stress, in-situ stress difference, fluid viscosity, and fluid pumping rate all play a role in shaping the fracture path. Frictional natural fractures connected to cavities significantly alter stress distribution, causing hydraulic fractures to deviate from their original direction. Natural cavities between adjacent fracturing stages have a significant impact on stress distribution, leading to irregular fracture propagation paths.
CMES-COMPUTER MODELING IN ENGINEERING & SCIENCES
(2021)
Article
Engineering, Geological
Fan Fei, Andre Costa, John E. Dolbow, Randolph R. Settgast, Matteo Cusini
Summary: In this paper, a novel phase-field model is proposed to simulate the nucleation and propagation of hydraulic fractures. The model accurately captures the material strength and considers the contribution of fluid pressure on crack driving force through external driving force and damage function. Numerical results demonstrate the accuracy and applicability of the proposed model.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2023)
Article
Energy & Fuels
Yu-Xuan Liu, Hang-Yu Zhou, Jian-Chun Guo, Qian Zhang, Chi Chen
Summary: The study investigated the effects of proppant type, concentration, and size on the apparent Young's modulus, and determined the controlling factors and mechanisms of fracture width reduction. The results showed a linear decrease in fracture width with increasing closure pressure for the ceramsite pack, with the apparent Young's modulus being associated with fracture aperture variation due to proppant embedment and deformation. Increasing proppant concentration or decreasing size led to higher apparent Young's modulus, with size having a more prominent effect, while mixed-size ceramsite packs showed slight improvements in propping ability. This study offers new insights into proppant pack deformation factors.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Geological
Li Zhuang, Arno Zang, Sunggyu Jung
Summary: This study investigated hydraulic fracture paths generated through cyclic and monotonic injection in different types of rocks, and quantitatively evaluated the hydraulic fractures. The study analyzed the role of different minerals and pre-existing defects in controlling hydraulic fracture propagation.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2022)
Article
Thermodynamics
Zhiqin Kang, Xing Jiang, Lei Wang, Dong Yang, Yulin Ma, Yangsheng Zhao
Summary: The authors used meter-scale oil shale as the experimental object to study the in situ heating technology for mining oil shale through steam injection. The results showed that hydraulic fracturing started at a pressure 0.34 times lower than the in situ stress, while high-temperature steam fracturing required a pressure 1.2 times higher than the in situ stress. The study also found that horizontal cracks were more easily formed in layered rock masses and that the thermal stress had a stronger influence on the fracture-inducing stress of the orebody.
Article
Mechanics
Fakai Dou, J. G. Wang, C. F. Leung, Zhanguo Ma
Summary: This paper numerically investigates the alterations of critical pore water pressure and the morphology of hydraulic fractures in shale formations with different near-wellbore fractures. The length, shape, and symmetry properties of near-wellbore fractures have significant impacts on pore water pressure variation and micro-crack propagation during hydraulic fracturing. These findings are helpful for the optimization design of hydraulic fracturing treatment.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Engineering, Geological
Xun Xi, Zoe K. Shipton, Jackie E. Kendrick, Andrew Fraser-Harris, Julien Mouli-Castillo, Katriona Edlmann, Christopher McDermott, Shangtong Yang
Summary: The interaction between hydraulic fractures (HF) and natural fractures (NF) during hydraulic fracturing process has a significant impact on fluid flow, proppant transport, and well productivity. This paper presents a new fracture model to investigate the near-wellbore interaction and validates the model through numerical simulations. The results show that high injection pressure tends to drive HF to cross NF located close to the wellbore, while low injection flow rate can help activate natural fractures near the wellbore.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Computer Science, Interdisciplinary Applications
Nima Haghighat, Amir Shoarian Sattari, Frank Wuttke
Summary: A numerical framework is proposed for analyzing desiccation fracturing in variably saturated porous media, and its capabilities in capturing unsaturated porous medium flow and coupled hydro-mechanical effects are tested against benchmark solutions. The mechanisms of desiccation cracking in soils are thoroughly investigated.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Environmental Sciences
Sahar Jannesarahmadi, Milad Aminzadeh, Roberto Raga, Nima Shokri
Summary: Microplastics have an impact on soil water evaporation dynamics and patterns, with the addition of microplastics leading to increased evaporation rates. The type of microplastics used also affects drying-induced cracking patterns.
Article
Mechanics
Feipeng Wu, Xianzhang Fan, De Li, Hongbin Yang, Jing Liu, Xiaojun Li
Summary: The main technology for removing deep plugging in unconsolidated sandstone reservoirs is deep penetrating hydraulic fracturing with chemical treatment. The study analyzed the effects of different viscosities and injection rates on fracture initiation and propagation, finding that high viscosity fracturing fluid at high injection rates can achieve hydraulic fracturing in high-permeability unconsolidated sandstone, and adjusting the viscosity and injection rate slightly higher than the threshold value can generate deep penetrating fractures in unconsolidated sandstones.
ENGINEERING FRACTURE MECHANICS
(2022)
Article
Engineering, Geological
Egor Dontsov
Summary: The purpose of this study is to investigate the morphology of simultaneously propagating hydraulic fractures from a horizontal well. The findings show that stress interaction between the fractures affects their shapes, with different parameters having different impacts.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2022)
Article
Mechanics
Feiyang Wang, Mingling Zhou, Wanqing Shen, Hongwei Huang, Jie He
Summary: A fluid-solid-phase multi-field coupling modeling method for hydraulic fracturing is proposed and implemented. The method controls the hydraulic fracture evolution using a unified fracture phase-field method and considers the fluid flow in the cracked domain as a Darcy-type flow. Simulation results show that the proposed method performs well in simulating hydraulic fracturing of saturated brittle porous media.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Mathematics, Interdisciplinary Applications
Bilal El-Kassem, Nizar Salloum, Thomas Brinz, Yousef Heider, Bernd Markert
Summary: This study aims to develop a numerical method to predict the influence of DEM parameters on various macroscopic responses in powder flow simulations. By using design of experiment and multivariate regression analysis, the impact of different material parameters on macroscopic output responses is revealed, highlighting the important role they play in powder flow.
COMPUTATIONAL PARTICLE MECHANICS
(2021)
Article
Engineering, Multidisciplinary
Yousef Heider, Kun Wang, WaiChing Sun
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2020)
Article
Thermodynamics
Mohamad Chaaban, Yousef Heider, Bernd Markert
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2020)
Article
Pharmacology & Pharmacy
Bilal El Kassem, Yousef Heider, Thomas Brinz, Bernd Markert
JOURNAL OF DRUG DELIVERY SCIENCE AND TECHNOLOGY
(2020)
Article
Engineering, Chemical
Bilal El Kassem, Nizar Salloum, Thomas Brinz, Yousef Heider, Bernd Markert
Summary: The study optimized the industrial auger dosing process for pharmaceutical powders using the Discrete Element Method (DEM) and proposed a method to reduce the number of parameter combinations while approaching reality. Multivariate regression analysis successfully predicted bulk behavior within the studied parameter ranges.
KONA POWDER AND PARTICLE JOURNAL
(2021)
Article
Engineering, Geological
Yousef Heider, Hyoung Suk Suh, WaiChing Sun
Summary: This paper presents a meta-modeling approach that utilizes deep reinforcement learning to automatically discover optimal neural network settings for the machine learning constitutive laws. By replacing the human modeler to handle the optimized choices of setup, the AI agent self-learns from taking a sequence of actions within the selection environment. The resulting ML-generated material models can be integrated into a finite element solver to solve initial-boundary-value problems.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2021)
Article
Pharmacology & Pharmacy
Bilal El Kassem, Thomas Brinz, Vahid Jenkouk, Yousef Heider, Bernd Markert
Summary: In this study, a vertical Loss-in-Weights feeder prototype was experimentally validated and functionally designed, demonstrating a semi-automated dosing machine for various powders. The prototype was verified through experimental sensitivity analysis and testing, confirming the design concept.
PHARMACEUTICAL DEVELOPMENT AND TECHNOLOGY
(2021)
Article
Engineering, Geological
A. H. Sweidan, K. Niggemann, Y. Heider, M. Ziegler, B. Markert
Summary: This research work presents an experimental and numerical study of the coupled thermo-hydro-mechanical (THM) processes that occur during soil freezing. The study distinguishes between two thermal states, focusing on thermal transient state and (quasi-) steady state. A numerical model based on continuum mechanical theory and phase-field modeling is proposed, showing capability in describing the freezing of saturated soils.
Article
Computer Science, Interdisciplinary Applications
Alexander Fuchs, Yousef Heider, Kun Wang, WaiChing Sun, Michael Kaliske
Summary: This study introduces a meta-modeling framework using artificial intelligence to replicate the path-dependent constitutive responses of composite materials; a Deep Reinforcement Learning combinatorics game is invented to search for optimal hyper-parameter sets automatically; it explores the trade-off between different hyper-parameter configurations and the possibility of transferring hyper-parameter knowledge among different RVEs.
COMPUTERS & STRUCTURES
(2021)
Article
Mathematics, Interdisciplinary Applications
Baharin Ali, Yousef Heider, Bernd Markert
Summary: This study embeds a phase-field model into a thermo-elastoplastic finite element model to simulate the GTAW process and estimate residual stresses in metallic components. The tracking of the moving melting front and consideration of temperature- and phase-field-dependent material properties allow for a detailed analysis and simulation of the metal material.
COMPUTATIONAL MECHANICS
(2022)
Article
Engineering, Geological
Mohamad Chaaban, Yousef Heider, Bernd Markert
Summary: In this paper, a reliable micro-to-macroscale framework is presented to model multiphase fluid flow through fractured porous media. The lattice Boltzmann method (LBM) is utilized within the phase-field modeling (PFM) of fractures to achieve this. New phase-field-dependent relationships for various parameters are proposed and a multiscale concept for coupling is achieved. Numerical simulations on real microgeometries of fractured porous media validate the reliability of the model.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2022)
Article
Engineering, Mechanical
Hossein Saberi, Hamid Saberi, Tinh Quoc Bui, Yousef Heider, Minh Ngoc Nguyen
Summary: In finite element analysis, adaptive mesh refinement (AMR) is commonly used to improve numerical solution accuracy in specific regions without refining the entire mesh. This study introduces a novel AMR technique for determining when and how to adjust element size during phase field fracture analysis, reducing computational cost without compromising accuracy. The technique involves approximating distance between field nodes in an existing mesh and performing remeshing as the crack propagates. Numerical examples demonstrate that this approach significantly reduces computational cost and maintains accuracy without prior knowledge of the crack propagation path. The technique also offers advantages in terms of convergence, ease of implementation, and applicability to irregular meshes.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Engineering, Geological
Cam-Lai Nguyen, Yousef Heider, Bernd Markert
Summary: This research aims to extend the isothermal continuum mechanical modeling framework of hydraulic fracturing in porous materials to account for the non-isothermal processes. The phase-field method is utilized for modeling the crack initiation and propagation, while the theory of porous media is used for the material description. New formulations are proposed to study the heat exchange between the fluid in the crack and the surrounding porous environment. The finite element method is used to solve the resulting strongly coupled partial differential equations and validate the stability and accuracy of the modeling scheme.
Article
Engineering, Geological
Mohamad Chaaban, Yousef Heider, Waiching Sun, Bernd Markert
Summary: The paper investigates the utilization of artificial neural networks (ANNs) in learning models to address the nonlinear anisotropic flow and hysteresis retention behavior of deformable porous materials. Simulations and databases are used to model single-phase and biphasic flow, and two different ML approaches are compared for the accuracy and speed of training. The outcomes demonstrate the capability of ML models in accurately and efficiently representing constitutive relations for permeability and hysteretic retention curves.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2023)
Article
Mechanics
Xiaolong Liu, Kelian Luo, Pengcheng Gao, Tao Cong, Xi Wang, Wenjing Wang
Summary: This paper investigates the formation mechanisms of the zig-zag crack region on the shattered rim of railway wheels. The zig-zag crack region, identified as a typical region for crack propagation in rolling contact fatigue behavior, was observed using scanning electron microscopy and transmission electron microscopy. The formation of the zig-zag morphology is attributed to the periodic deflection of the propagation path relative to the initial propagation plane, caused by the limited plastic deformation zone at the crack tip. Grain refinement and secondary cracks in the zig-zag crack region are a result of the large compressive and shear stresses induced by rolling contact loading.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Anastasia Iziumova, Aleksei Vshivkov, Ivan Panteleev, Virginia Mubassarova, Oleg Plekhov, Denis Davydov
Summary: The aim of this study was to investigate the correlation between structural, acoustic emission, and thermal characteristics of fatigue crack growth in titanium alloys. Cluster analysis of the acoustic emission signals revealed two different types of signals observed during the fatigue crack development. It was experimentally demonstrated that the stored energy tends to reach an asymptotic value at the final stage of fatigue crack growth and this is correlated with the twinning process intensification in titanium alloy Ti Grade 2. A correlation was assumed between the stages of change in heat flux, the cumulative energy of the first cluster of acoustic emission signals, and the crack length.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
M. Vieira de Carvalho, I. A. Rodrigues Lopes, F. M. Andrade Pires
Summary: This study investigates the numerical challenges of fracture mechanics models within implicit quasi-static frameworks and proposes an instability criterion. The ratio of cohesive to internal power is identified as a crucial factor. Two strategies for handling fracture problems with instabilities are discussed and a comparative assessment is performed. The study also examines more complex material responses, including transformation-induced plasticity effects.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Thomas Duminy, Aurelien Doitrand, Sylvain Meille
Summary: This study conducted in situ wedge splitting tests on millimeter-size PMMA samples and proposed a method to determine the material tensile strength and critical energy release rate using digital image correlation and a full finite element implementation of the coupled criterion.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Xin Chang, Xingyi Wang, Chunhe Yang, Yintong Guo, Yanghui Wan
Summary: The influence of cyclic thermal shock and high-temperature acid etching on the Mode I fracture of shale was investigated in this study. It was found that cyclic thermal shock severely degrades the strength and fracture toughness of shale, while high-temperature acid etching treatment improves the fracture toughness. These findings are valuable for optimizing process parameters to reduce initiation pressure in deep shale formations.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Liaojun Yao, Mingyue Chuai, Zhangming Lyu, Xiangming Chen, Licheng Guo, R. C. Alderliesten
Summary: Methods based on fracture mechanics have been widely used in fatigue delamination growth (FDG) characterization of composite laminates. This study proposes appropriate similitude parameters to represent FDG behavior with different R-ratios.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Zesheng Zang, Zhonghui Li, Yue Niu, Shan Yin
Summary: This study conducted experiments and recorded signals to investigate the fracture behavior and damage evolution characteristics of coal samples. The results showed that as loading proceeds, the stress, electric potential (EP), and acoustic emission (AE) values increase, and EP and AE signals are excited when stress drops. The fracture behavior of coal samples is altered by flaw inclination, and the destruction mode becomes increasingly complicated. The damage evolution characteristics of coal samples can be evaluated and analyzed by defining the coefficient of variation (CV value) of EP and the b value of AE.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Clotilde Berdin, Nathalie Prud'homme
Summary: In this study, zirconia layers with different fractions of tetragonal phase and thicknesses were tested for multi-cracking behavior. Cracks perpendicular to the tensile direction were observed, showing a blunting effect into the substrate. The ratio of crack spacing at saturation to layer thickness decreased as the layer thickness increased. Unit cell modeling was used to establish a relationship between crack spacing and layer strength, which fell within the bounds of Hu and Evans model and was found to be insensitive to the tetragonal zirconia fraction.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Huadong Zhang, Weichen Kong, Y. H. Liu, Yuh J. Chao
Summary: Williams' series expansion crack tip solution in linear elasticity is modified to include a uniform crack face pressure. Practical methods to calculate T-stress from near crack tip stresses are outlined. The analytical results are consistent with numerical results.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Jiahao Kong, Haoyue Han, Tao Wang, Guangyan Huang, Zhuo Zhuang
Summary: This paper introduces a phase-field model for polymer foam materials by combining the phase-field method with the crushable foam model. The model is calibrated using experimental data and successfully simulates the fracture processes of polyurethane under different loading conditions. The study is important for the engineering applications of polymer foam materials.
ENGINEERING FRACTURE MECHANICS
(2024)