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Coupled computational fluiddynamics–discrete-element method investigation of soil contact erosion under cyclic hydraulic loading:A multiscale perspective 认领 引用
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作者 Xianfeng Diao Guoqing Cai +3 位作者 Tao Liu Peiyun Zhang Yanlin Su Bangzheng Rao 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2026年第6期4812-4830,共19页
Tidal waves,intermittent rainfall,and fluctuations in water levels,which create cyclic hydraulic gradients,can exacerbate the migration of fine particles within soils and lead to deterioration in stability.However,mac... Tidal waves,intermittent rainfall,and fluctuations in water levels,which create cyclic hydraulic gradients,can exacerbate the migration of fine particles within soils and lead to deterioration in stability.However,macroscale experimental methods struggle to capture the microscopic deformations that occur during seepage-induced erosion.Therefore,this study,which is based on the coupled computational fluid dynamics–discrete element method(CFD–DEM)coupling method,investigates the contact mechanical mechanisms that induce macroscopic deformation under cyclic hydraulic gradients by considering the effects of different amplitudes and frequencies.The results show that the erosion mass of fine particles increases in a stepwise manner,with a multipeak variation in the erosion rate,and both the erosion amount and intensity are greater under constant gradient conditions.Fine particles erode primarily near the contact surface and,after migration,accumulate mainly in the coarse particle layers close to the contact surface.Increasing the amplitude and frequency of the cyclic hydraulic gradient leads to more fine particle blockages within the coarse particle layer.The cyclic hydraulic gradient causes the contact force chain network to repeatedly break and reorganize,reducing the shear strengths of the soil and resulting in more pronounced anisotropy in the contact force distribution. 展开更多
关键词 Computational fluid dynamics–discrete element method(CFD–DEM)coupling Contact erosion Cyclic hydraulic gradients Macroscopic deformation Micromechanism
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Wellbore breakouts in heavily fractured rocks:A coupled discrete fracture network-distinct element method analysis 认领 引用 被引量：3
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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》 SCIE CSCD 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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Discrete element simulations to predict the response of bio-cemented sands 认领 引用 被引量：1
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作者 Pu Yang Edward Kavazanjian Narayanan Neithalath 《Biogeotechnics》 2025年第4期2-11,共10页
Discrete element method(DEM)-based numerical models in the YADE environment are used to simulate the constitutive response of uncemented and bio-cemented sands to investigate the influence of boundary conditions,loadi... Discrete element method(DEM)-based numerical models in the YADE environment are used to simulate the constitutive response of uncemented and bio-cemented sands to investigate the influence of boundary conditions,loading and testing conditions,and material types.Both the classical DEM model and the pore scale finite volume(PFV)-coupled DEM model are used to simulate the response of saturated uncemented and lightly cemented sands with a rigid wall boundary under both drained and undrained triaxial compression.A DEM model with flexible boundaries created using particle facet(PFacet)elements is used to simulate undrained triaxial compression of moderately cemented sands,including the influence of confining stress.The PFacet-based model is used to predict the transition from barreling failure to shear banding when the confining stress or the cementation degree increases.The classical DEM model with cohesive bonds of uniform strength is also used to successfully simulate the uniaxial compression response of a sand with an extremely high degree of cementation.Finally,this paper presents a particle-packing model consisting of multiple solid phases for cemented sands based on the understanding that not all particle types will have the same cohesive properties.This multiple solidphase model is a refinement of the classical DEM model that represents the particle physics more realistically,especially for heterogeneous systems.A preliminary parametric study is carried out considering varying cohesive properties and volume fractions for the different solid phases. 展开更多
关键词 Discrete element method(DEM) Triaxial compression Unconfined compression Bio-cementation Shear band
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Visualization of the formation and features of soil arching within a piled embankment by discrete element method simulation 认领 引用 被引量：10
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作者 Han-jiang LAI Jun-jie ZHENG +1 位作者 Rong-jun ZHANG Ming-juan CUI 《Journal of Zhejiang University-SCIENCE A》 SCIE EI CAS CSCD 2016年第10期803-817,共15页
Piled embankments are widely used in highway and railway engineering due to their economy and efficiency inovercoming several issues encountered in constructing embankments over weak soils. Soil arching, caused by the... Piled embankments are widely used in highway and railway engineering due to their economy and efficiency inovercoming several issues encountered in constructing embankments over weak soils. Soil arching, caused by the pile-subsoilrelative displacement （△s）, plays an important role in reducing the embankment load falling on weak soil, however, the funda-mental characteristics （e.g., formation and features） of soil arching remain poorly understood. In this study, a series of discreteelement method （DEM） modellings are performed to study the formation and features of soil arching with the variation of As inpiled embankments with or without geosynthetic reinforcement. Firstly, calibration for the modelling parameters is carried out bycomparing the DEM results with the experimental data obtained from the existing literature. Secondly, the analysis of the macro-and micro-behaviours is performed in detail. Finally, a parametric study is conducted in an effort to identify the influences of threekey factors on soil arching： the friction coefficient of the embankment fill （f）, the embankment height （h）, and the pile clear spacing（s-a）. Numerical results indicate that △s is a key factor governing the formation and features of soil arching in embankments. Tobe specific, soil arching gradually evolves from two inclined shear planes at a small △s to a hemispherical arch at a relatively largeAs. Then, with a continuous increase in △s, the soil arching height gradually increases and finally approaches a constant value of0.8（s-a） （i.e., the maximum soil arching height）. For a given case, the higher the soil arching height, the greater the degree of soilarching effect. The parametric study shows that the friction coefficient of the embankment fill has a negligible influence on theformation and features of soil arching. However, embankment height is a key factor governing the formation and features of soilarching. In addition, pile clear spacing has a significant effect on the formation of soil arching, but not on its features. 展开更多
关键词 Piled embankment, Numerical simulation, Discrete element method (DEM), Soil arching, Formation, Features
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A review of methods,applications and limitations for incorporating fluid flow in the discrete element method 认领 引用 被引量：16
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作者 Tuo Wang Fengshou Zhang +1 位作者 Jason Furtney Branko Damjanac 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2022年第3期1005-1024,共20页
The past decade has witnessed the substantial growth in research interests and progress on the subject of coupled hydro-mechanical processes in rocks and soils,driven mainly by the surge of research in unconventional ... The past decade has witnessed the substantial growth in research interests and progress on the subject of coupled hydro-mechanical processes in rocks and soils,driven mainly by the surge of research in unconventional hydrocarbon reservoirs and associated hazards.Many coupling techniques have been developed to include the effects of fluid flow in the discrete element method(DEM),and the techniques have been applied to a variety of geomechanical problems.Although these coupling methods have been successfully applied in various engineering fields,no single fluid/DEM coupling method is universal due to the complexity of engineering problems and the limitations of the numerical methods.For researchers and engineers,the key to solve a specific problem is to select the most appropriate fluid/DEM coupling method among these modeling technologies.The purpose of this paper is to give a comprehensive review of fluid flow/DEM coupling methods and relevant research.Given their importance,the availability or unavailability of best practice guidelines is outlined.The theoretical background and current status of DEM are introduced first,and the principles,applications,and advantages and disadvantages of different fluid flow/DEM coupling methods are discussed.Finally,a summary with speculation on future development trends is given. 展开更多
关键词 Hydro-mechanical process Fluid/discrete element method(DEM) coupling Geomechanics Numerical modeling
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Analysis of the breakage parameters of railway ballast based on the discrete element method 认领 引用 被引量：6
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作者 Gan-zhong LIU Jia-cheng DAI +3 位作者 Ping WANG Rong CHEN Hao LIU Xian-kui WEI 《Journal of Zhejiang University-SCIENCE A》 SCIE EI CAS CSCD 2023年第3期257-271,共15页
During the service lives of ballasted tracks,the ballast experiences degradation,such as breakage and fragmentation,which reduces the stability of the tracks.Ballast breakage is directly related to the shapes,sizes,an... During the service lives of ballasted tracks,the ballast experiences degradation,such as breakage and fragmentation,which reduces the stability of the tracks.Ballast breakage is directly related to the shapes,sizes,and stress states of particles.The key to solving this problem is to determine the breakage parameters of railway ballast.In this study,through uniaxial compression and uniaxial shear tests,the factors associated with ballast breakage for a simple stress state were obtained.Then,a refined discrete element model of railway ballast was established.The Box-Behnken method was used to design a simulation test,and a response surface method was used to obtain the optimal ballast breakage parameters.Lastly,the results of a direct shear test were compared with the simulation results to verify the correctness of the parameters and to study the shear resistance of the ballast aggregates.The results showed that for ballast particles with sizes of 22.4–63.0 mm,the characteristic stresses of compression and shear were not significantly affected by the size of the particles,but were greatly affected by their shape.In particular,long particles were more likely to break.During the direct shear test,the cumulative ballast breakage ratio gradually increased to 13.97%.The optimal breakage parameters of the ballast determined by this approach have high application value in the management of ballasted tracks. 展开更多
关键词 Ballasted track Breakage parameters Discrete element method(DEM) Response surface
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Coupled FEM-DEM modeling of permeability evolution in rough fractured shale during shearing under varying confining pressures 认领 引用 被引量：2
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作者 Bin Li Qi Li 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2026年第3期1736-1754,共19页
The dynamic evolution of fracture permeability presents a critical scientific challenge in rock masses.Understanding the mechanisms of rock mass permeability evolution is vital for engineering project design and opera... The dynamic evolution of fracture permeability presents a critical scientific challenge in rock masses.Understanding the mechanisms of rock mass permeability evolution is vital for engineering project design and operations.By integrating the discrete element method(DEM)with the finite element method(FEM),a numerical simulation framework for shear seepage in rough fractured shale has been developed to investigate the dynamic mechanisms of permeability evolution under varying confining pressures and during the shearing process.Numerical simulations were conducted on rough fractured samples under effective confining pressures ranging from 5 MPa to 20 MPa to monitor the aperture and permeability evolution of the fracture.The results of the numerical simulation are consistent with the experimental observations,indicating that both the shearing process and confining pressure significantly influence permeability.Moreover,the magnitude of the confining pressure is a crucial factor influencing the trend in permeability changes.Under a confining pressure of 5 MPa,fracture permeability initially increases significantly but decreases post-shearing.In contrast,a continuous decrease in fracture permeability is observed when the confining pressure exceeds 10 MPa.The results of the shear numerical simulation indicate that the confining pressure restricts fracture dilation during shearing,promotes the generation of rock debris,and decreases both the permeability and transmissivity of the fracture.The wear results obtained from numerical simulations are consistent with the experimental patterns and correlate with the joint roughness coefficient(JRC).This study proposed an effective numerical simulation method to reveal the evolution mechanism of fracture flow capacity,taking into account the wear of the fracture surface in shear simulations and the initial stress state of the rock in seepage simulations.This research explains the permeability evolution mechanism of fractured shale from a microscopic perspective,and the proposed numerical simulation method for shear seepage provides a powerful means to uncover the dynamic evolution mechanisms governing fracture permeability. 展开更多
关键词 Discrete element method(DEM) Finite element method(FEM) Fracture Permeability Shear stress Joint roughness coefficient(JRC) Dynamic evolution
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Influence of heterogeneity on rock strength and stiffness using discrete element method and parallel bond model 认领 引用 被引量：15
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作者 Spyridon Liakas Catherine O’Sullivan Charalampos Saroglou 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2017年第4期575-584,共10页
The particulate discrete element method(DEM) can be employed to capture the response of rock,provided that appropriate bonding models are used to cement the particles to each other.Simulations of laboratory tests are ... The particulate discrete element method(DEM) can be employed to capture the response of rock,provided that appropriate bonding models are used to cement the particles to each other.Simulations of laboratory tests are important to establish the extent to which those models can capture realistic rock behaviors.Hitherto the focus in such comparison studies has either been on homogeneous specimens or use of two-dimensional(2D) models.In situ rock formations are often heterogeneous,thus exploring the ability of this type of models to capture heterogeneous material behavior is important to facilitate their use in design analysis.In situ stress states are basically three-dimensional(3D),and therefore it is important to develop 3D models for this purpose.This paper revisits an earlier experimental study on heterogeneous specimens,of which the relative proportions of weaker material(siltstone) and stronger,harder material(sandstone) were varied in a controlled manner.Using a 3D DEM model with the parallel bond model,virtual heterogeneous specimens were created.The overall responses in terms of variations in strength and stiffness with different percentages of weaker material(siltstone) were shown to agree with the experimental observations.There was also a good qualitative agreement in the failure patterns observed in the experiments and the simulations,suggesting that the DEM data enabled analysis of the initiation of localizations and micro fractures in the specimens. 展开更多
关键词 Discrete element method(DEM) Heterogeneous rocks Strength and stiffness Parallel bond model
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Effect of heterogeneity on mechanical and micro-seismic behaviors of sandstone subjected to multi-level cyclic loading: A discrete element method investigation 认领 引用 被引量：5
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作者 Zhengyang Song Zhen Yang +3 位作者 Min Zhang Fei Wang Martin Herbst Heinz Konietzky 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第10期2556-2581,共26页
In numerical simulation of the mechanical responses and acoustic emission(AE)characteristics of rocks under cyclic loading,the impacts of compositional heterogeneities of mineral grains have barely been considered.Thi... In numerical simulation of the mechanical responses and acoustic emission(AE)characteristics of rocks under cyclic loading,the impacts of compositional heterogeneities of mineral grains have barely been considered.This will lead to a poor reproduction of rock’s behaviors in terms of stress-strain relationship and micro-seismic characteristics in numerical simulation.This work aims to analyze and reveal the impact of parameter heterogeneity on the rock’s fatigue and micro-seismic properties based on PFC3D.Two distribution patterns(uniform and Weibull distributions),are implemented to assign four critical parameters(i.e.tensile strength,cohesion,parallel bond stiffness and linear stiffness)for 32 sets of numerical schemes.The results show that the models with high heterogeneity of tensile strength and cohesion can better reproduce the stress-strain relationship as well as the patterns of cumulative AE counts and energy magnitude.The evolution of the proportion of three-level AE events in the laboratory test is consistent with the numerical results when the highly heterogeneous tensile strength and cohesion are distributed.The numerical results can provide practical guidance to the PFC-based modeling of rock heterogeneity when exposed to multi-level cyclic loading and AE monitoring. 展开更多
关键词 Discrete element method(DEM) Heterogeneity Weibull distribution PFC3D Cyclic loading Acoustic emission(AE)
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A new method to simulate irregular particles by discrete element method 认领 引用 被引量：5
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作者 Rui Gao Xin Du +2 位作者 Yawu Zeng Yong Li Jing Yan 《Journal of Rock Mechanics and Geotechnical Engineering》 2012年第3期276-281,共6页
Granular materials are ubiquitous in nature and important in various applications such as road and railway engineering. Granular materials exhibit complicated mechanical behaviors, which are affected significantly by ... Granular materials are ubiquitous in nature and important in various applications such as road and railway engineering. Granular materials exhibit complicated mechanical behaviors, which are affected significantly by the irregular shape of particles. Currently, the discrete element method (DEM) has been accepted as an effective approach to investigate the mechanical behaviors of granular materials. However, there are scarce simulations based on DEM in literatures considering the irregularity of particle shape. A new method is proposed to simulate individual real particle with irregular shape using clump constituted by overlapping spheres. First, the geometric model of real particle with surface nodes and inner nodes is established through digitally processing the computerized tomography (CT) scanning data. Second, a clump consisting of spheres is generated to simulate the real particle using a minimum distance criterion. The criterion is implemented by tree optimization algorithm. Influential factors are also introduced to balance the model accuracy and computing cost. Effects of the influential factors, including the density of geometric grid and the minimum distance, on simulations are discussed. Results show that this new method is simpler and more efficient than the previous methods in terms of the model accuracy and computing cost. 展开更多
关键词 irregular particles discrete element method (DEM) influential factors
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Discrete element method study of hysteretic behavior and deformation characteristics of rockfill material under cyclic loading 认领 引用 被引量：4
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作者 Mingchun LIN Guanqi WANG +3 位作者 Jian ZHOU Wei ZHOU Ni AN Gang MA 《Journal of Zhejiang University-SCIENCE A》 SCIE EI CAS CSCD 2023年第4期350-365,共16页
Granular geomaterials under different loading conditions manifest various behaviors,such as hysteresis.Understanding their hysteretic behavior and deformation characteristics is the basis for establishing a constituti... Granular geomaterials under different loading conditions manifest various behaviors,such as hysteresis.Understanding their hysteretic behavior and deformation characteristics is the basis for establishing a constitutive relation with excellent performance in deformation prediction.The deformation characteristics of crushable particle materials are analyzed through a series of cyclic loading tests conducted by numerical simulation.The hysteretic behavior is investigated from a particle scale.The increase in particles with contacts less than two may be responsible for the residual strain,and the particle breakage further promotes particle rearrangement and volume contraction.Both the accumulation of plastic strain and the resilient modulus are found to be related to confining pressures,stress levels,cyclic loading amplitudes,and the number of cycles.The plastic strain accumulation can be written as a function of the number of cycles and an evolution function of resilient modulus is proposed. 展开更多
关键词 Granular material Discrete element method(DEM) Plastic deformation Cyclic loading Hysteretic behavior
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Examining the influence of the loading path on the cracking characteristics of a pre-fractured rock specimen with discrete element method simulation 认领 引用 被引量：4
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作者 Kang DUAN Ri-hua JIANG +2 位作者 Xue-jian LI Lu-chao WANG Ze-ying YANG 《Journal of Zhejiang University-SCIENCE A》 SCIE EI CAS CSCD 2023年第4期332-349,共18页
Damage in a rock mass is heavily dependent on the existence and growth of joints,which are also influenced by the complex stress states induced by human activities(e.g.,tunneling and excavation).A proper representatio... Damage in a rock mass is heavily dependent on the existence and growth of joints,which are also influenced by the complex stress states induced by human activities(e.g.,tunneling and excavation).A proper representation of the loading path is essential for understanding the mechanical behaviors of rock masses.Based on the discrete element method(DEM),the influence of the loading path on the cracking process of a rock specimen containing an open flaw is examined.The effectiveness of the model is confirmed by comparing the simulation results under a uniaxial compression test to existing research findings,where wing crack initiates first and secondary cracks contribute to the failure of the specimen.Simulation results confirm that the cracking process is dependent upon both the confining pressure and the loading path.Under the axial loading test,a higher confining pressure suppresses the development of tensile wing cracks and forces the formation of secondary cracks in the form of shear bands perpendicular to the flaw.Increase of confining pressure also decreases the influence of the loading path on the cracking process.Reduction of confining pressure during an unloading test amplifies the concentration of tensile stress and ultimately promotes the appearance of a tensile splitting fracture at meso-scale.Confining pressure at the failure stage is well predicted by the Hoek-Brown failure criterion under quasi-static conditions. 展开更多
关键词 Cracking process Loading path Fractured rock mass Discrete element method(DEM) Local stress concentration
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Applicability of discrete element method with spherical and clumped particles for constitutive study of granular materials 认领 引用 被引量：8
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作者 Tongming Qu Min Wang Yuntian Feng 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2022年第1期240-251,共12页
Discrete element method(DEM)has been intensively used to study the constitutive behaviour of granular materials.However,to what extent a real granular material can be reproduced by virtual DEM simulations remains uncl... Discrete element method(DEM)has been intensively used to study the constitutive behaviour of granular materials.However,to what extent a real granular material can be reproduced by virtual DEM simulations remains unclear.This study attempts to answer this question by comparing DEM simulations with typical features of experimental granular materials.Three groups of models with spherical and clumped particles are investigated from four perspectives:(i)deviatoric stress and volumetric behaviour;(ii)critical state behaviour;(iii)stress-dilatancy relationship;and(iv)the evolution of principal stress ratio against axial strain.The results demonstrate that DEM with spherical or clumped particles is capable of qualitatively describing macroscopic deviatoric stress responses,volumetric behaviour,and critical state behaviour observed in experiments for granular materials.On the other hand,some qualitative deviations between experiments and the investigated DEM simulations are also observed,in terms of the stress-dilatancy behaviour and principal stress ratio against axial strain,which are proven to be critical for constitutive modelling.The results demonstrate that DEM with spherical or clumped particles may not necessarily fully capture experimental features of granular materials even from a qualitative perspective.It is thus encouraged to thoroughly validate DEM with experiments when developing constitutive models based on DEM observations. 展开更多
关键词 Discrete element method(DEM) Granular materials Constitutive behaviour Deviatoric hardening model Rolling resistance model Irregular particles
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Micromechanical modeling of hollow cylinder torsional shear test on sand using discrete element method 认领 引用 被引量：4
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作者 Shunxiang Song Pei Wang +1 位作者 Zhenyu Yin Yi Pik Cheng 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第12期5193-5208,共16页
Previous studies on the hollow cylinder torsional shear test(HCTST)have mainly focused on the macroscopic behavior,while the micromechanical responses in soil specimens with shaped particles have rarely been investiga... Previous studies on the hollow cylinder torsional shear test(HCTST)have mainly focused on the macroscopic behavior,while the micromechanical responses in soil specimens with shaped particles have rarely been investigated.This paper develops a numerical model of the HCTST using the discrete element method(DEM).The method of bonded spheres in a hexagonal arrangement is proposed to generate flexible boundaries that can achieve real-time adjustment of the internal and external cell pressures and capture the inhomogeneous deformation in the radial direction during shearing.Representative angular particles are selected from Toyoura sand and reproduced in this model to approximate real sand particles.The model is then validated by comparing numerical and experimental results of HCTSTs on Toyoura sand with different major principal stress directions.Next,a series of HCTSTs with different combinations of major principal stress direction(a)and intermediate principal stress ratio(b)is simulated to quantitatively characterize the sand behavior under different shear conditions.The results show that the shaped particles are horizontally distributed before shearing,and the initial anisotropic packing structure further results in different stressestrain curves in cases with different a and b values.The distribution of force chains is affected by both a and b during the shear process,together with the formation of the shear bands in different patterns.The contact normal anisotropy and contact force anisotropy show different evolution patterns when either a or b varies,resulting in the differences in the non-coaxiality and other macroscopic responses.This study improves the understanding of the macroscopic response of sand from a microscopic perspective and provides valuable insights for the constitutive modeling of sand. 展开更多
关键词 Sand Hollow cylinder torsional shear test(HCTST) Discrete element method(DEM) Principal stress rotation Micromechanics Anisotropy
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NUMERICAL ANALYSIS OF SOIL PLUG INSIDE SUCTION FOUNDATIONS DURING SUCTION PENETRATION BY DISCRETE ELEMENT METHOD 认领 引用 被引量：5
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作者 杜杰 丁红岩 +1 位作者 张浦阳 张超 《Transactions of Tianjin University》 EI CAS 2006年第1期61-65,共5页
The phenomenon of the soil plug usually rising inside the suction foundations during suction penetration was quantitatively described and predicted. The formation process of the soil plug was simulated and calculated ... The phenomenon of the soil plug usually rising inside the suction foundations during suction penetration was quantitatively described and predicted. The formation process of the soil plug was simulated and calculated by DEM （discrete element method） model. The seepage flow, the self-weight of soil, the friction on the chamber wall as well as the suction inside the chamber are considered as the main external forces in the process. The results are compared with a set of laboratory model tests performed by using three soil types （sand, silty clay and clay） in the Bohai Sea area. The heights of soil plug from numerical estimations are lower than those from model test results, mainly because the suction pressure and friction resistance are applied in an ideal way under the numerical simulation. 展开更多
关键词 suction foundation soil plug discrete element method （DEM） seepage flow
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Capability of discrete element method to investigate the macro-micro mechanical behaviours of granular soils considering different stress conditions and morphological gene mutation 认领 引用 被引量：1
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作者 Wei Xiong Jianfeng Wang Zhuang Cheng 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第10期2731-2745,共15页
Discrete element method(DEM)has been widely utilised to model the mechanical behaviours of granular materials.However,with simplified particle morphology or rheology-based rolling resistance models,DEM failed to descr... Discrete element method(DEM)has been widely utilised to model the mechanical behaviours of granular materials.However,with simplified particle morphology or rheology-based rolling resistance models,DEM failed to describe some responses,such as the particle kinematics at the grain-scale and the principal stress ratio against axial strain at the macro-scale.This paper adopts a computed tomography(CT)-based DEM technique,including particle morphology data acquisition from micro-CT(mCT),spherical harmonic-based principal component analysis(SH-PCA)-based particle morphology reconstruction and DEM simulations,to investigate the capability of DEM with realistic particle morphology for modelling granular soils’micro-macro mechanical responses with a consideration of the initial packing state,the morphological gene mutation degree,and the confining stress condition.It is found that DEM with realistic particle morphology can reasonably reproduce granular materials’micro-macro mechanical behaviours,including the deviatoric stressevolumetric straineaxial strain response,critical state behaviour,particle kinematics,and shear band evolution.Meanwhile,the role of multiscale particle morphology in granular soils depends on the initial packing state and the confining stress condition.For the same granular soils,rougher particle surfaces with a denser initial packing state and a higher confining stress condition result in a higher degree of shear strain localisation. 展开更多
关键词 Discrete element method(DEM) Spherical harmonic-based principal component analysis(SH-PCA) Particle morphology Granular so
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Soil desiccation cracking under a non-uniform temperature field:Experimental investigation and DEM modeling 认领 引用
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作者 Tao Wang Chao-Sheng Tang +2 位作者 Luan Lin Ting-Ting Chen Zhao-Lin Cai 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2026年第6期4782-4795,共14页
Soil desiccation cracking significantly impacts the hydraulic and mechanical properties of soil.Although extensive research has been conducted on cracking under uniform conditions,the influence of non-uniform temperat... Soil desiccation cracking significantly impacts the hydraulic and mechanical properties of soil.Although extensive research has been conducted on cracking under uniform conditions,the influence of non-uniform temperature fields remains poorly understood.This study combines laboratory experiments and discrete element method(DEM)simulations to investigate soil desiccation cracking under non-uniform temperature fields.Laboratory tests utilized a controlled heating setup to establish a temperature gradient,with digital image correlation(DIC)employed to analyze strain and displacement fields.DEM simulations incorporated a temperature-dependent evaporation model to capture the micromechanical behavior of soil particles under non-uniform thermal conditions.The results reveal that cracks initiate near the high-temperature region and propagate in a"fish-scale"pattern toward the low-temperature region,driven by differential evaporation and uneven shrinkage.A distinct dry/wet interface forms and migrates from the high-temperature to the low-temperature region as evaporation progresses.DEM simulations accurately reproduced the observed crack patterns,demonstrating the model's capability to capture the effects of non-uniform temperature fields on soil cracking.Furthermore,the simulations indicate that crack propagation is governed by the movement of tensile stress concentrations,which are more pronounced in high-temperature regions.This study highlights the critical role of temperature gradients in desiccation cracking,offering valuable insights for geotechnical engineering and enhancing predictive models under varying environmental conditions. 展开更多
关键词 Desiccation cracks Non-uniform temperature field Experiment Discrete element method(DEM)modeling Evaporation rate
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Monte Carlo simulation method for estimating the fine rattler fraction in large-ratio binary mixtures 认领 引用
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作者 Jing WANG Changyu SHI Daosheng LING 《Journal of Zhejiang University-SCIENCE A》 SCIE EI CAS CSCD 2026年第3期231-245,共15页
Reliable estimation of the fine particle rattler fraction is crucial for understanding the structural and mechanical responses of binary granular systems with large size ratios.However,such estimation is challenged by... Reliable estimation of the fine particle rattler fraction is crucial for understanding the structural and mechanical responses of binary granular systems with large size ratios.However,such estimation is challenged by the general inability to obtain interparticle contact force information directly from experimental images and by the lower accuracy of positional and size identification of fine particles compared with coarse particles.To address these challenges,in this study,we focused on 2D bidisperse granular assemblies with large size ratios(α=7,9,12,and 16)and developed an approach based on Monte Carlo simulation(MCS)that relies solely on the size and positional information of coarse particles,avoiding the need for force-resolved computations.The performance of the method was evaluated against experimental measurements and discrete element method(DEM)simulations.The MCS-based predictions show close agreement with experimental results,with a slight overall overestimation.At low fines content,the approach tends to overestimate the fine particle rattler fraction relative to DEM results,whereas at higher fines content,it underestimates the rattler fraction.Overall,the proposed MCS-based approach enables robust and relatively accurate estimation of the fine particle rattler fraction.This study provides a practical framework for predicting the rattler fraction,contributes to advancing both experimental analysis and theoretical modeling in granular physics,and demonstrates the conceptual extendibility of the MCS framework to more complex 3D packings. 展开更多
关键词 Granular materials Rattlers Fines content Size ratio Discrete element method(DEM) Monte Carlo
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基于CFD-DEM耦合方法的浮冰区船舶阻力数值模拟 认领 引用
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作者 徐佩 郭迎春 +2 位作者 寇莹 王超 孙乾洋 《振动与冲击》 EI CSCD 北大核心 2026年第13期60-70,共11页
基于计算流体力学-离散元耦合方法(computational fluid dynamics-discrete element method,CFD-DEM),运用STAR-CCM+软件,对船舶在浮冰区航行过程中的冰阻力特性与破冰机理开展了系统的数值模拟分析。为保证模拟结果的数值可靠性,首先... 基于计算流体力学-离散元耦合方法(computational fluid dynamics-discrete element method,CFD-DEM),运用STAR-CCM+软件,对船舶在浮冰区航行过程中的冰阻力特性与破冰机理开展了系统的数值模拟分析。为保证模拟结果的数值可靠性,首先完成了网格收敛性验证,并通过多尺度网格加密及敏感性分析,确定了兼顾计算效率与模拟精度的最优数值模型。研究重点考察了船舶航速与浮冰厚度两个关键参数对冰阻力的非线性影响规律,揭示了船-冰相互作用中冰阻力变化与破碎能量耗散的内在机制。进一步从应力波传播、断裂模式、动能转化等角度,对不同工况下浮冰的破碎程度、裂纹扩展路径及碎冰堆积形态进行了定量评估与定性分析。该研究深化了对船-冰-水多相耦合动力学行为的理解,并为极地船舶冰区航行性能优化与抗冰结构设计提供了可靠的数值分析方法与工程参考。 展开更多
关键词 浮冰 船舶 计算流体力学-离散元耦合方法(CFD-DEM) 冰阻力 数值模拟
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SPH-DEM-FEM流固耦合模型下泥石流冲击框架损伤评估 认领 引用
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作者 张金 张忠耀 +1 位作者 张高 莫洋洋 《振动与冲击》 EI CSCD 北大核心 2026年第6期141-153,163,共13页
泥石流作为高破坏性混合流体,其携带的块石对框架结构的冲击机制尚未得到充分研究。为揭示含块石泥石流冲击框架结构的动力响应与损伤机制,基于光滑粒子流体动力学-离散元法-有限元法(smoothed particle hydrodynamics-discrete element... 泥石流作为高破坏性混合流体,其携带的块石对框架结构的冲击机制尚未得到充分研究。为揭示含块石泥石流冲击框架结构的动力响应与损伤机制,基于光滑粒子流体动力学-离散元法-有限元法(smoothed particle hydrodynamics-discrete element method-finite element method,SPH-DEM-FEM)耦合数值方法,构建流体-块石-结构的多耦合数值模型,模拟不同冲击速度和角度下框架结构的损伤过程,并结合两相溃坝试验来验证模型有效性。研究表明:泥石流冲击导致结构损伤经历“接触-扩散-反弹-堆积/冲击”四个阶段,当冲击速度超过6.00 m/s时,结构产生不可恢复损伤,且块石阻隔作用使流体上部冲击力大于下部,引发结构中部最先发生集中损伤;此外,冲击力峰值随速度和角度增大呈非线性增长,10.00 m/s与90°工况下框架柱底冲击力达497.17 kN,超过结构抗冲击承载力;最后,数值模拟与经验公式所得冲击力结果误差在13.95%~29.00%,数量级一致,验证了模型可靠性。研究结果可为泥石流高发区框架结构的抗冲击设计提供参考。 展开更多
关键词 框架结构 泥石流冲击 光滑粒子流体动力学-离散元法-有限元法(SPH-DEM-FEM) 冲击力
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