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An Inner-Element Edge-Based Smoothed Finite Element Method
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作者 Zhigang Pei Wei Xie +1 位作者 Tao Suo Zhimin Xu 《Acta Mechanica Solida Sinica》 2025年第5期815-824,共10页
A modified inner-element edge-based smoothed finite element method(IES-FEM)is developed and integrated with ABAQUS using a user-defined element(UEL)in this study.Initially,the smoothing domain discretization of IES-FE... A modified inner-element edge-based smoothed finite element method(IES-FEM)is developed and integrated with ABAQUS using a user-defined element(UEL)in this study.Initially,the smoothing domain discretization of IES-FEM is described and compared with ES-FEM.A practical modification of IES-FEM is then introduced that used the technique employed by ES-FEM for the nodal strain calculation.The differences in the strain computation among ES-FEM,IES-FEM,and FEM are then discussed.The modified IES-FEM exhibited superior performance in displacement and a slight advantage in stress compared to FEM using the same mesh according to the results obtained from both the regular and irregular elements.The robustness of the IES-FEM to severely deformed meshes was also verified. 展开更多
关键词 Smoothed finite element method(S-FEM) Edge-based smoothed finite element method(ES-FEM) User-defined element(UEL) Stress analysis Displacement analysis
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Study of the Transport Behavior of Multispherical Proppant in Intersecting Fracture Based on Discrete Element Method 被引量:1
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作者 Chengyong Peng JianshuWu +2 位作者 Mao Jiang Biao Yin Yishan Lou 《Energy Engineering》 EI 2025年第1期185-201,共17页
To analyze the differences in the transport and distribution of different types of proppants and to address issues such as the short effective support of proppant and poor placement in hydraulically intersecting fract... To analyze the differences in the transport and distribution of different types of proppants and to address issues such as the short effective support of proppant and poor placement in hydraulically intersecting fractures,this study considered the combined impact of geological-engineering factors on conductivity.Using reservoir production parameters and the discrete elementmethod,multispherical proppants were constructed.Additionally,a 3D fracture model,based on the specified conditions of the L block,employed coupled(Computational Fluid Dynamics)CFD-DEM(Discrete ElementMethod)for joint simulations to quantitatively analyze the transport and placement patterns of multispherical proppants in intersecting fractures.Results indicate that turbulent kinetic energy is an intrinsic factor affecting proppant transport.Moreover,the efficiency of placement and migration distance of low-sphericity quartz sand constructed by the DEM in the main fracture are significantly reduced compared to spherical ceramic proppants,with a 27.7%decrease in the volume fraction of the fracture surface,subsequently affecting the placement concentration and damaging fracture conductivity.Compared to small-angle fractures,controlling artificial and natural fractures to expand at angles of 45°to 60°increases the effective support length by approximately 20.6%.During hydraulic fracturing of gas wells,ensuring the fracture support area and post-closure conductivity can be achieved by controlling the sphericity of proppants and adjusting the perforation direction to control the direction of artificial fractures. 展开更多
关键词 Hydraulic fracturing discrete element method PROPPANT SPHERICITY CFD-DEM
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Frictional Adhesive Contact of Multiferroic Coatings Based on the Hybrid Element Method
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作者 Yanxin Li Bo Pan +3 位作者 Yun Tian Lili Ma Nicola Menga Xin Zhang 《Acta Mechanica Solida Sinica》 2025年第4期624-641,共18页
This paper investigates the frictional adhesive contact of a rigid,electrically/magnetically conductive spherical indenter sliding past a multiferroic coating deposed onto a rigid substrate,based on the hybrid element... This paper investigates the frictional adhesive contact of a rigid,electrically/magnetically conductive spherical indenter sliding past a multiferroic coating deposed onto a rigid substrate,based on the hybrid element method.The adhesion behavior is described based on the Maugis-Dugdale model.The adhesion-driven conjugate gradient method is employed to calculate the distribution of unknown pressures,while the discrete convolution-fast Fourier transform is utilized to compute the deformations,surface electric and magnetic potentials as well as the subsurface stresses,electric displacements,and magnetic inductions.The goal of this study is to investigate the influences of adhesion parameter,friction coefficient,coating thickness,and surface electric and magnetic charge densities on contact behaviors,such as contact area and pressures,electric and magnetic potentials,and subsurface stresses. 展开更多
关键词 Frictional contact ADHESION Multiferroic coating DC-FFT Hybrid element method
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Investigation of hanging crosstie problem at bridge approaches:a train–track–bridge model coupled with discrete element method
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作者 Zhongyi Liu Wenjing Li +2 位作者 Travis A.Shoemaker Erol Tutumluer Youssef M.A.Hashash 《Railway Engineering Science》 2025年第3期458-473,共16页
Nonuniform track support and differential settlements are commonly observed in bridge approaches where the ballast layer can develop gaps at crosstie-ballast interfaces often referred to as a hanging crosstie conditio... Nonuniform track support and differential settlements are commonly observed in bridge approaches where the ballast layer can develop gaps at crosstie-ballast interfaces often referred to as a hanging crosstie condition.Hanging crossties usually yield unfavorable dynamic effects such as higher wheel loads,which negatively impact the serviceability and safety of railway operations.Hence,a better understanding of the mechanisms that cause hanging crossties and their effects on the ballast layer load-deformation characteristics is necessary.Since the ballast layer is a particulate medium,the discrete element method(DEM),which simulates ballast particle interactions individually,is ideal to explore the interparticle contact forces and ballast movements under dynamic wheel loading.Accurate representations of the dynamic loads from the train and track superstructure are needed for high-fidelity DEM modeling.This paper introduces an integrated modeling approach,which couples a single-crosstie DEM ballast model with a train–track–bridge(TTB)model using a proportional–integral–derivative control loop.The TTB–DEM model was validated with field measurements,and the coupled model calculates similar crosstie displacements as the TTB model.The TTB–DEM provided new insights into the ballast particle-scale behavior,which the TTB model alone cannot explore.The TTB–DEM coupling approach identified detrimental effects of hanging crossties on adjacent crossties,which were found to experience drastic vibrations and large ballast contact force concentrations. 展开更多
关键词 Hanging crosstie Crosstie gap Transition zone Model coupling Discrete element method Train-track model
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Fast 2D forward modeling of electromagnetic propagation well logs using finite element method and data-driven deep learning
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作者 A.M.Petrov A.R.Leonenko +1 位作者 K.N.Danilovskiy O.V.Nechaev 《Artificial Intelligence in Geosciences》 2025年第1期85-96,共12页
We propose a novel workflow for fast forward modeling of well logs in axially symmetric 2D models of the nearwellbore environment.The approach integrates the finite element method with deep residual neural networks to... We propose a novel workflow for fast forward modeling of well logs in axially symmetric 2D models of the nearwellbore environment.The approach integrates the finite element method with deep residual neural networks to achieve exceptional computational efficiency and accuracy.The workflow is demonstrated through the modeling of wireline electromagnetic propagation resistivity logs,where the measured responses exhibit a highly nonlinear relationship with formation properties.The motivation for this research is the need for advanced modeling al-gorithms that are fast enough for use in modern quantitative interpretation tools,where thousands of simulations may be required in iterative inversion processes.The proposed algorithm achieves a remarkable enhancement in performance,being up to 3000 times faster than the finite element method alone when utilizing a GPU.While still ensuring high accuracy,this makes it well-suited for practical applications when reliable payzone assessment is needed in complex environmental scenarios.Furthermore,the algorithm’s efficiency positions it as a promising tool for stochastic Bayesian inversion,facilitating reliable uncertainty quantification in subsurface property estimation. 展开更多
关键词 PETROPHYSICS Electromagnetic propagation logging Forward modeling Finite element method Residual neural networks
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Coupling Magneto-Electro-Elastic Multiscale Finite Element Method for Transient Responses of Heterogeneous MEE Structures
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作者 Xiaolin Li Xinyue Li +2 位作者 Liming Zhou Hangran Yang Xiaoqing Yuan 《Computers, Materials & Continua》 2025年第3期3821-3841,共21页
Magneto-electro-elastic(MEE)materials are widely utilized across various fields due to their multi-field coupling effects.Consequently,investigating the coupling behavior of MEE composite materials is of significant i... Magneto-electro-elastic(MEE)materials are widely utilized across various fields due to their multi-field coupling effects.Consequently,investigating the coupling behavior of MEE composite materials is of significant importance.The traditional finite element method(FEM)remains one of the primary approaches for addressing such issues.However,the application of FEM typically necessitates the use of a fine finite element mesh to accurately capture the heterogeneous properties of the materials and meet the required computational precision,which inevitably leads to a reduction in computational efficiency.To enhance the computational accuracy and efficiency of the FEM for heterogeneous multi-field coupling problems,this study presents the coupling magneto-electro-elastic multiscale finite element method(CM-MsFEM)for heterogeneous MEE structures.Unlike the conventional multiscale FEM(MsFEM),the proposed algorithm simultaneously constructs displacement,electric,and magnetic potential multiscale basis functions to address the heterogeneity of the corresponding parameters.The macroscale formulation of CM-MsFEM was derived,and the macroscale/microscale responses of the problems were obtained through up/downscaling calculations.Evaluation using numerical examples analyzing the transient behavior of heterogeneous MEE structures demonstrated that the proposed method outperforms traditional FEM in terms of both accuracy and computational efficiency,making it an appropriate choice for numerically modeling the dynamics of heterogeneous MEE structures. 展开更多
关键词 Multiscale finite element method heterogeneous materials transient responses MAGNETO-ELECTRO-ELASTIC multiscale basis function
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Investigation of the effect of particle composition on its distribution homogeneity in aggregate blend using discrete element method
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作者 Weixiao Yu Sudi Wang +1 位作者 Zhenlong Gong Yinghao Miao 《Journal of Road Engineering》 2025年第1期116-127,共12页
The homogeneity of aggregate blend has a significant influence on the performance of asphalt mixture.The composition of aggregate blend,including the size combination and the mass ratio between each size particles(MRE... The homogeneity of aggregate blend has a significant influence on the performance of asphalt mixture.The composition of aggregate blend,including the size combination and the mass ratio between each size particles(MRESP),is an important factor affecting the homogeneity.This study investigated the influence of the size combination and MRESP on the distribution homogeneity of particles in aggregate blend using discrete element method(DEM).An indicator quantifying the distribution homogeneity was established according to the coefficient of variation(CV)for particle number.Two-size,three-size,and four-size aggregate blends with various compositions were designed.Laboratory tests show the DEM simulation is feasible.The particle distribution homogeneity in various blends was analyzed.The results showed the distribution homogeneity of each size particles in a blend is closely related to their mass fraction.The higher the mass fraction of the particles,the more homogeneous the distribution of them.The MRESP has no significant influence on the homogeneity of the blend composed of only coarse aggregates.However,the homogeneity of the blend composed of coarse and fine aggregates improves gradually with the increase of the mass fraction of fine aggregates.The smaller the maximum particle size in a blend,the better the homogeneity.It is suggested that the mass fraction of fine aggregates should be between 33%and 50%for achieving good homogeneity of aggregate blends.The research results can provide a reference for gradation design of asphalt mixture. 展开更多
关键词 Aggregate blend Distribution homogeneity Particle combination Discrete element method
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A stochastic energy finite element method for predicting the high-frequency dynamic response of panels under aero-thermo-acoustic loads
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作者 Zhaolin CHEN Yueming DU +1 位作者 Yingsong GU Zhichun YANG 《Chinese Journal of Aeronautics》 2025年第8期367-387,共21页
Skin panels on supersonic vehicles are subjected to aero-thermo-acoustic loads,resulting in a well-known multi-physics dynamic problem.The high-frequency dynamic response of these panels significantly impacts the stru... Skin panels on supersonic vehicles are subjected to aero-thermo-acoustic loads,resulting in a well-known multi-physics dynamic problem.The high-frequency dynamic response of these panels significantly impacts the structural safety of supersonic vehicles,but it has been rarely investigated.Given that existing methods are inefficient for high-frequency dynamic analysis in multi-physics fields,the present work addresses this challenge by proposing a Stochastic Energy Finite Element Method(SEFEM).SEFEM uses energy density instead of displacement to describe the dynamic response,thereby significantly enhancing its efficiency.In SEFEM,the effects of aerodynamic and thermal loads on the energy propagation characteristics are studied analytically and incorporated into the energy density governing equation.These effects are also considered when calculating the input power generated by the acoustic load,and two effective approaches named Frequency Response Function Method(FRFM)and Mechanical Impedance Method(MIM)are developed accordingly and integrated into SEFEM.The good accuracy,applicability,and high efficiency of the proposed SEFEM are demonstrated through numerical simulations performed on a two-dimensional panel under aero-thermoacoustic loads.Additionally,the effects and underlying mechanisms of aero-thermo-acoustic loads on the high-frequency response are explored.This work not only presents an efficient approach for predicting high-frequency dynamic response of panels subjected to aero-thermo-acoustic loads,but also provides insights into the high-frequency dynamic characteristics in multi-physics fields. 展开更多
关键词 Aero-thermo-acoustic loads High frequency Multi-physics field Stochastic energy finite element method Vibration analysis
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The influence of stress and natural fracture on a stimulated deep shale reservoir using the boundary element method
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作者 Songze Liao Ziming Zhang +1 位作者 Jinghong Hu Yuan Zhang 《Natural Gas Industry B》 2025年第3期298-315,共18页
Hydraulic fracturing plays a critical role in enhancing shale gas production in deep shale reservoirs.Conventional hydraulic fracturing simulation methods rely on prefabricated grids,which can be hindered by the chall... Hydraulic fracturing plays a critical role in enhancing shale gas production in deep shale reservoirs.Conventional hydraulic fracturing simulation methods rely on prefabricated grids,which can be hindered by the challenge of being computationally overpowered.This study proposes an efficient fracturing simulator to analyze fracture morphology during hydraulic fracturing processes in deep shale gas reservoirs.The simulator integrates the boundary element displacement discontinuity method and the finite volume method to model the fluid-solid coupling process by employing a pseudo-3D fracture model to calculate the fracture height.In particular,the Broyden iteration method was introduced to improve the computational efficiency and model robustness;it achieved a 46.6%reduction in computation time compared to the Newton-Raphson method.The influences of horizontal stress differences,natural fracture density,and natural fracture angle on the modified zone of the reservoir were simulated,and the following results were observed.(1)High stress difference reservoirs have smaller stimulated reservoir area than low stress difference reservoirs.(2)A higher natural fracture angle resulted in larger modification zones at low stress differences,while the effect of a natural fracture angle at high stress differences was not significant.(3)High-density and long natural fracture zones played a significant role in enhancing the stimulated reservoir area.These findings are critical for comprehending the impact of geological parameters on deep shale reservoirs. 展开更多
关键词 Hydraulic fracturing Deep fractured shale Boundary element method Numerical simulation
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Shape Sensitivity Analysis of Acoustic Scattering with Series Expansion Boundary Element Methods
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作者 Fan Li Hongxue Liu +2 位作者 Yongsong Li Leilei Chen Haojie Lian 《Computer Modeling in Engineering & Sciences》 2025年第6期2785-2809,共25页
This study explores a sensitivity analysis method based on the boundary element method(BEM)to address the computational complexity in acoustic analysis with ground reflection problems.The advantages of BEM in acoustic... This study explores a sensitivity analysis method based on the boundary element method(BEM)to address the computational complexity in acoustic analysis with ground reflection problems.The advantages of BEM in acoustic simulations and its high computational cost in broadband problems are examined.To improve efficiency,a Taylor series expansion is applied to decouple frequency-dependent terms in BEM.Additionally,the SecondOrder Arnoldi(SOAR)model order reduction method is integrated to reduce computational costs and enhance numerical stability.Furthermore,an isogeometric sensitivity boundary integral equation is formulated using the direct differentiation method,incorporating Cauchy principal value integrals and Hadamard finite part integrals to handle singularities.The proposed method improves the computational efficiency,and the acoustic sensitivity analysis provides theoretical support for further acoustic structure optimization. 展开更多
关键词 Isogeometric boundary element method ground reflection broadband acoustics acoustic scattering
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Investigation of interaction behavior between hydraulic fractures and gravels in heterogeneous glutenite using a grain-based discrete element method
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作者 Zhao-Peng Zhang Yu-Shi Zou +1 位作者 Hai-Yan Zhu Shi-Cheng Zhang 《Petroleum Science》 2025年第1期348-369,共22页
The glutenite reservoir is strongly heterogeneous due to the random distribution of gravels, making it challenging to perform hydraulic fracturing effectively. To solve this issue, it is essential to study interaction... The glutenite reservoir is strongly heterogeneous due to the random distribution of gravels, making it challenging to perform hydraulic fracturing effectively. To solve this issue, it is essential to study interaction behavior between hydraulic fractures(HFs) and gravels. A coupled hydro-mechanical model is proposed for HF propagation in glutenite using a grain-based discrete element method. This paper first investigates the dynamic evolution of HFs in glutenite, then analyzes the influences of various factors such as horizontal stress difference(Δσ), minimum horizontal stress(σh), gravel content(Vg), gravel size(dg), and stiffness ratio of gravel to matrix(Rs) on HF propagation geometries. Results show that penetrating the gravel is the primary HF-gravel interaction behavior, which follows sequential and staggered initiation modes. Bypassing the gravel is the secondary behavior, which obeys the sequential initiation mode and occurs when the orientation of the gravel boundary is inclined to the maximum horizontal stress(σH). An offset along the gravel boundary is usually formed while penetrating gravels, and the offsets may cause fracture widths to decrease by 37.8%-84.4%. Even if stress dominates the direction of HF propagation, HFs still tend to deflect within gravels. The deviation angle from σH decreases with rising Δσand increases with the increase of dgand Rs. Additionally, intra-gravel shear HFs(IGS-HFs) are prone to be generated in coarse-grained glutenite under high Δσ, while more gravel-bypassing shear HFs(GBSHFs) tend to be created in argillaceous glutenite with high Rsthan in sandy glutenite with low Rs. The findings above prompt the emergence of a novel HF propagation pattern in glutenite, which helps to understand the real HF geometries and to provide theoretical guidance for treatments in the field. 展开更多
关键词 Hydraulic fracture propagation Fractureegravel interaction behavior Grain-based discrete element method GLUTENITE
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Investigation on the fracture propagation for horizontal wells in hydrate reservoirs using a fluid-solid coupling discrete element method
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作者 Jia-wei Zhang Chang-ling Liu +2 位作者 Yong-chao Zhang Le-le Liu Yun-kai Ji 《China Geology》 2025年第4期765-778,共14页
Hydraulic fracturing technology has played an important role in the exploitation of unconventional oil and gas resources,however,its application to gas hydrate reservoirs has been rarely studied.Currently,there is sti... Hydraulic fracturing technology has played an important role in the exploitation of unconventional oil and gas resources,however,its application to gas hydrate reservoirs has been rarely studied.Currently,there is still limited understanding of the propagation and extension of fractures around the wellbore during the fracturing process of horizontal wells in hydrate reservoirs,as well as the stress interference patterns between fractures.This study simulates hydraulic fracturing processes in hydrate reservoirs using a fluidsolid coupling discrete element method(DEM),and analyzes the impacts of hydrate saturation and geological and engineering factors on fracture extension and stress disturbance.The results show that hydraulic fracturing is more effective when hydrate saturation exceeds 30%and that fracture pressure increases with saturation.The increase in horizontal stress differential enhances the directionality of fracture propagation and reduces stress disturbance.The distribution uniformity index(DUI)reveals that injection pressure is directly proportional to the number of main fractures and inversely proportional to fracturing time,with fracturing efficiency depending on the spacing between injection points and the distance between wells.This work may provide reference for the commercial exploitation of natural gas hydrates. 展开更多
关键词 Hydraulic fracturing technology Gas hydrate reservoirs Hydrate-bearing sediment Discrete element method Fluid-solid coupling Hydraulic fracturing Horizontal wells Fracture propagation Oil-gas exploration engineering
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Revealling pore microstructure impacts on the compressive strength of porous proppant based on finite and discrete element method
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作者 Zijia Liao Hesamoddin Rabiee +5 位作者 Lei Ge Xiaogang Li Zhaozhong Yang Qi Xue Chao Shen Hao Wang 《Journal of Materials Science & Technology》 2025年第8期72-81,共10页
Ceramic spheres,typically with a particle diameter of less than 0.8 mm,are frequently utilized as a critical proppant material in hydraulic fracturing for petroleum and natural gas extraction.Porous ceramic spheres wi... Ceramic spheres,typically with a particle diameter of less than 0.8 mm,are frequently utilized as a critical proppant material in hydraulic fracturing for petroleum and natural gas extraction.Porous ceramic spheres with artificial inherent pores are an important type of lightweight proppant,enabling their transport to distant fracture extremities and enhancing fracture conductivity.However,the focus frequently gravitates towards the low-density advantage,often overlooking the pore geometry impacts on compressive strength by traditional strength evaluation.This paper numerically bypasses such limitations by using a combined finite and discrete element method(FDEM)considering experimental results.The mesh size of the model undergoes validation,followed by the calibration of cohesive element parameters via the single particle compression test.The stimulation elucidates that proppants with a smaller pore size(40μm)manifest crack propagation evolution at a more rapid pace in comparison to their larger-pore counterparts,though the influence of pore diameter on overall strength is subtle.The inception of pores not only alters the trajectory of crack progression but also,with an increase in porosity,leads to a discernible decline in proppant compressive strength.Intriguingly,upon crossing a porosity threshold of 10%,the decrement in strength becomes more gradual.A denser congregation of pores accelerates crack propagation,undermining proppant robustness,suggesting that under analogous conditions,hollow proppants might not match the strength of their porous counterparts.This exploration elucidates the underlying mechanisms of proppant failure from a microstructural perspective,furnishing pivotal insights that may guide future refinements in the architectural design of porous proppant. 展开更多
关键词 Porous proppant Finite and discrete element method(FDEM) CRACK Compressive strength
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Effects of spatial heterogeneity on pseudo-static stability of coal mine overburden dump slope,using random limit equilibrium and random finite element methods:A comparative study
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作者 Madhumita Mohanty Rajib Sarkar Sarat Kumar Das 《Earthquake Engineering and Engineering Vibration》 2025年第1期83-99,共17页
Sudden and unforeseen seismic failures of coal mine overburden(OB)dump slopes interrupt mining operations,cause loss of lives and delay the production of coal.Consideration of the spatial heterogeneity of OB dump mate... Sudden and unforeseen seismic failures of coal mine overburden(OB)dump slopes interrupt mining operations,cause loss of lives and delay the production of coal.Consideration of the spatial heterogeneity of OB dump materials is imperative for an adequate evaluation of the seismic stability of OB dump slopes.In this study,pseudo-static seismic stability analyses are carried out for an OB dump slope by considering the material parameters obtained from an insitu field investigation.Spatial heterogeneity is simulated through use of the random finite element method(RFEM)and the random limit equilibrium method(RLEM)and a comparative study is presented.Combinations of horizontal and vertical spatial correlation lengths were considered for simulating isotropic and anisotropic random fields within the OB dump slope.Seismic performances of the slope have been reported through the probability of failure and reliability index.It was observed that the RLEM approach overestimates failure probability(P_(f))by considering seismic stability with spatial heterogeneity.The P_(f)was observed to increase with an increase in the coefficient of variation of friction angle of the dump materials.Further,it was inferred that the RLEM approach may not be adequately applicable for assessing the seismic stability of an OB dump slope for a horizontal seismic coefficient that is more than or equal to 0.1. 展开更多
关键词 coal mine overburden dump slope random limit equilibrium method random finite element method seismic slope stability spatial heterogeneity
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Wellbore breakouts in heavily fractured rocks:A coupled discrete fracture network-distinct element method analysis
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作者 Yongcun Feng Yaoran Wei +4 位作者 Zhenlai Tan Tianyu Yang Xiaorong Li Jincai Zhang Jingen Deng 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第3期1685-1699,共15页
Wellbore breakout is one of the critical issues in drilling due to the fact that the related problems result in additional costs and impact the drilling scheme severely.However,the majority of such wellbore breakout a... Wellbore breakout is one of the critical issues in drilling due to the fact that the related problems result in additional costs and impact the drilling scheme severely.However,the majority of such wellbore breakout analyses were based on continuum mechanics.In addition to failure in intact rocks,wellbore breakouts can also be initiated along natural discontinuities,e.g.weak planes and fractures.Furthermore,the conventional models in wellbore breakouts with uniform distribution fractures could not reflect the real drilling situation.This paper presents a fully coupled hydro-mechanical model of the SB-X well in the Tarim Basin,China for evaluating wellbore breakouts in heavily fractured rocks under anisotropic stress states using the distinct element method(DEM)and the discrete fracture network(DFN).The developed model was validated against caliper log measurement,and its stability study was carried out by stress and displacement analyses.A parametric study was performed to investigate the effects of the characteristics of fracture distribution(orientation and length)on borehole stability by sensitivity studies.Simulation results demonstrate that the increase of the standard deviation of orientation when the fracture direction aligns parallel or perpendicular to the principal stress direction aggravates borehole instability.Moreover,an elevation in the average fracture length causes the borehole failure to change from the direction of the minimum in-situ horizontal principal stress(i.e.the direction of wellbore breakouts)towards alternative directions,ultimately leading to the whole wellbore failure.These findings provide theoretical insights for predicting wellbore breakouts in heavily fractured rocks. 展开更多
关键词 Wellbore breakout Discrete fracture network(DFN) Distinct element method(DEM) Heavily fractured rocks
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Damage evolution of surrounding sandstone rock under charging–discharging cyclic loading in the natural gas storage of abandoned mines based on the discrete element method
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作者 Zhanguo Ma Junyu Sun +3 位作者 Peng Gong Erwin Oh Jun Hu Ruichong Zhang 《Deep Underground Science and Engineering》 2025年第2期329-338,共10页
Gas storage in abandoned mines is one way to reuse waste space resources.The surrounding rock of gas storage reservoirs in underground roadways undergoes damage and deformation under the cyclic loading of gas charging... Gas storage in abandoned mines is one way to reuse waste space resources.The surrounding rock of gas storage reservoirs in underground roadways undergoes damage and deformation under the cyclic loading of gas charging and discharging,which can pose a risk to the safety of the reservoirs.This study establishes a true triaxial numerical model of rock mass with the discrete element method(DEM)and explores the crack evolution of surrounding rock of underground gas storage during cyclic loading and unloading.Also,a damage evolution model in numerical analysis considering residual deformation is developed to explain the experimental results.As was revealed,cyclic loading and unloading resulted in fatigue damage in the specimen and caused strength deterioration of the specimen.During the loading process,the uniformly distributed force chains of the rock mass redistributed,evolving gradually to mostly transverse force chains.This contributed to the appearance of blank areas in the force chains when through cracks appear.The ratio of tensile cracks to shear cracks gradually decreases and finally stabilizes at 7:1.The damage evolution model considering residual strain can be mutually verified with the numerical simulation results.Based on the DEM model,it was found that there was a certain threshold of confining pressure.When the confining pressure exceeded 30 MPa,the deformation to ductility of sandstone samples began to accelerate,with a greater residual strength.This study provides a theoretical basis for analyzing the long-term mechanical behavior of surrounding rock of gas storage in abandoned mines. 展开更多
关键词 damage evolution model of surrounding rock discrete element method force chains gas charging-discharging cycle gas storage in abandoned mines
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Optimal Error Estimates of Multiphysics Finite Element Method for a Nonlinear Poroelasticity Model with Nonlinear Stress-Strain Relation
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作者 GE Zhi-hao LI Hai-run LI Ting-ting 《Chinese Quarterly Journal of Mathematics》 2025年第3期271-294,共24页
In this paper,we propose a multiphysics finite element method for a nonlinear poroelasticity model with nonlinear stress-strain relation.Firstly,we reformulate the original problem into a new coupled fluid system-a ge... In this paper,we propose a multiphysics finite element method for a nonlinear poroelasticity model with nonlinear stress-strain relation.Firstly,we reformulate the original problem into a new coupled fluid system-a generalized nonlinear Stokes problem of displacement vector field related to pseudo pressure and a diffusion problem of other pseudo pressure fields.Secondly,a fully discrete multiphysics finite element method is performed to solve the reformulated system numerically.Thirdly,existence and uniqueness of the weak solution of the reformulated model and stability analysis and optimal convergence order for the multiphysics finite element method are proven theoretically.Lastly,numerical tests are given to verify the theoretical results. 展开更多
关键词 Nonlinear poroelasticity model Multiphysics finite element method Back-ward Euler method
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3D slope stability analysis considering strength anisotropy by a microstructure tensor enhanced elasto-plastic finite element method
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作者 Wencheng Wei Hongxiang Tang +1 位作者 Xiaoyu Song Xiangji Ye 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第3期1664-1684,共21页
This article presents a micro-structure tensor enhanced elasto-plastic finite element(FE)method to address strength anisotropy in three-dimensional(3D)soil slope stability analysis.The gravity increase method(GIM)is e... This article presents a micro-structure tensor enhanced elasto-plastic finite element(FE)method to address strength anisotropy in three-dimensional(3D)soil slope stability analysis.The gravity increase method(GIM)is employed to analyze the stability of 3D anisotropic soil slopes.The accuracy of the proposed method is first verified against the data in the literature.We then simulate the 3D soil slope with a straight slope surface and the convex and concave slope surfaces with a 90turning corner to study the 3D effect on slope stability and the failure mechanism under anisotropy conditions.Based on our numerical results,the end effect significantly impacts the failure mechanism and safety factor.Anisotropy degree notably affects the safety factor,with higher degrees leading to deeper landslides.For concave slopes,they can be approximated by straight slopes with suitable boundary conditions to assess their stability.Furthermore,a case study of the Saint-Alban test embankment A in Quebec,Canada,is provided to demonstrate the applicability of the proposed FE model. 展开更多
关键词 Strength anisotropy Elasto-plastic finite element method(FEM) Three-dimensional(3D)soil slope Gravity increase method(GIM) Stability analysis Case study
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Assessment of slurry chamber clogging alleviation during ultra-large-diameter slurry tunnel boring machine tunneling in hard-rock using computational fluid dynamics-discrete element method:A case study
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作者 Yidong Guo Xinggao Li +2 位作者 Dalong Jin Hongzhi Liu Yingran Fang 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第8期4715-4734,共20页
To fundamentally alleviate the excavation chamber clogging during slurry tunnel boring machine(TBM)advancing in hard rock,large-diameter short screw conveyor was adopted to slurry TBM of Qingdao Jiaozhou Bay Second Un... To fundamentally alleviate the excavation chamber clogging during slurry tunnel boring machine(TBM)advancing in hard rock,large-diameter short screw conveyor was adopted to slurry TBM of Qingdao Jiaozhou Bay Second Undersea Tunnel.To evaluate the discharging performance of short screw conveyor in different cases,the full-scale transient slurry-rock two-phase model for a short screw conveyor actively discharging rocks was established using computational fluid dynamics-discrete element method(CFD-DEM)coupling approach.In the fluid domain of coupling model,the sliding mesh technology was utilized to describe the rotations of the atmospheric composite cutterhead and the short screw conveyor.In the particle domain of coupling model,the dynamic particle factories were established to produce rock particles with the rotation of the cutterhead.And the accuracy and reliability of the CFD-DEM simulation results were validated via the field test and model test.Furthermore,a comprehensive parameter analysis was conducted to examine the effects of TBM operating parameters,the geometric design of screw conveyor and the size of rocks on the discharging performance of short screw conveyor.Accordingly,a reasonable rotational speed of screw conveyor was suggested and applied to Jiaozhou Bay Second Undersea Tunnel project.The findings in this paper could provide valuable references for addressing the excavation chamber clogging during ultra-large-diameter slurry TBM tunneling in hard rock for similar future. 展开更多
关键词 Slurry tunnel boring machine(TBM) Short screw conveyor Slurry chamber clogging Computational fluid dynamics-discrete element method(CFD-DEM)coupled modeling Engineering application
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A program for modeling the RF wave propagation of ICRF antennas utilizing the finite element method
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作者 Lei-Yu Zhang Yi-Xuan Li +1 位作者 Ming-Yue Han Quan-Zhi Zhang 《Chinese Physics B》 2025年第4期154-160,共7页
Controlled nuclear fusion represents a significant solution for future clean energy,with ion cyclotron range of frequency(ICRF)heating emerging as one of the most promising technologies for heating the fusion plasma.T... Controlled nuclear fusion represents a significant solution for future clean energy,with ion cyclotron range of frequency(ICRF)heating emerging as one of the most promising technologies for heating the fusion plasma.This study primarily presents a self-developed 2D ion cyclotron resonance antenna electromagnetic field solver(ICRAEMS)code implemented on the MATLAB platform,which solves the electric field wave equation by using the finite element method,establishing perfectly matched layer(PML)boundary conditions,and post-processing the electromagnetic field data.This code can be utilized to facilitate the design and optimization processes of antennas for ICRF heating technology.Furthermore,this study examines the electric field distribution and power spectrum associated with various antenna phases to investigate how different antenna configurations affect the electromagnetic field propagation and coupling characteristics. 展开更多
关键词 ion cyclotron range of frequency(ICRF)antennas finite element method perfect matching layer
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