Granular Matter最新文献_第10页

Microscopic mechanical properties of rockfill materials under different stress paths 不同应力路径下填石材料的微观力学性能

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-03-11 DOI: 10.1007/s10035-024-01413-7

Runhan Zhang, Lingkai Zhang, Chong Shi, Yonggang Zhang, Yunchao Cui

{"title":"Microscopic mechanical properties of rockfill materials under different stress paths","authors":"Runhan Zhang, Lingkai Zhang, Chong Shi, Yonggang Zhang, Yunchao Cui","doi":"10.1007/s10035-024-01413-7","DOIUrl":"10.1007/s10035-024-01413-7","url":null,"abstract":"<div><p>The mechanical properties of rockfill materials are not only influenced by microscopic factors such as particle morphology and gradation, but also closely related to different loading stress paths. It is of great significance to study the microscopic mechanical properties of rockfill materials under different stress paths for revealing the macroscopic mechanical properties as well as the microscopic deformation and failure mechanisms of rockfill materials. In this paper, based on the results of triaxial tests, a series of numerical triaxial simulation tests under different stress paths were carried out using the discrete element particle flow method, and the deformation, strength change rules, and fine structure evolution mechanism under three stress paths were explored. The results demonstrated that there were significant differences in the effects of stress paths on the stress–strain and strain-volume change characteristics of the rockfill materials. Stress paths exhibited little effect on the strength characteristics. The anisotropy of strong contact number and strong contact force was the microscopic source of macroscopic strength. The contact situation between the particles was the main microscopic factor affecting the macroscopic deformation. The intrinsic mechanism of macroscopic deformation properties could be revealed by the average coordination number and porosity. The stress path affected the growth rate of the number of bond failures and the total number of failures. The relationship between macroscopic mechanical properties and microstructural evolution under different stress paths was also discussed. The findings can provide meaningful insights into the deformation control and stability analysis of rockfill engineering.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"26 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140098078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Macro-and-micromechanical responses of ballast under triaxial shearing using coupled DEM–FDM with flexible and rigid membranes: a comparative study 使用带柔性和刚性膜的耦合 DEM-FDM 进行三轴剪切下压载的宏观和微观力学响应：对比研究

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-03-11 DOI: 10.1007/s10035-024-01412-8

Cheng Chen, Dao-kun Wu, Yifei Sun, Xin Zhang

{"title":"Macro-and-micromechanical responses of ballast under triaxial shearing using coupled DEM–FDM with flexible and rigid membranes: a comparative study","authors":"Cheng Chen, Dao-kun Wu, Yifei Sun, Xin Zhang","doi":"10.1007/s10035-024-01412-8","DOIUrl":"10.1007/s10035-024-01412-8","url":null,"abstract":"<div><p>Railway ballast undergoes rearrangement, abrasion, and even breakage, when subjected to high-speed train loads. To reproduce the deformation and degradation behavior of ballast under realistic boundaries used in laboratory triaxial tests, bonded particle clusters and clumps sampled within flexible and rigid boundaries were established, using the discrete element method and finite difference method. The models were then calibrated and validated against a series of experimental results. It is found that boundary condition has a considerable effect on the contact force chains and coordination number. The flexible boundary induces more uniform stress distribution between particle contacts, and consequently higher strength, lower dilation, and impartial breakage. A unimodal frequency distribution of the coordination number is observed when using flexible boundary, while rigid boundary can result in multi-modal distribution in breakable specimens. The flexible boundary also induces more particle breakage with high fragmentation. The rigid boundary specimens exhibit a bimodal distribution of particle breakage along the specimen height after test, with fewer fragments existing in the middle part; however, a unimodal distribution of particle breakage is found in the flexible boundary ones, which agrees more with the laboratory observation.</p></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"26 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140127416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An inclusion model for predicting granular elasticity incorporating force chain mechanics 结合力链力学预测颗粒弹性的包含模型

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-03-10 DOI: 10.1007/s10035-024-01411-9

Adyota Gupta, K. T. Ramesh, Ryan Hurley

{"title":"An inclusion model for predicting granular elasticity incorporating force chain mechanics","authors":"Adyota Gupta, K. T. Ramesh, Ryan Hurley","doi":"10.1007/s10035-024-01411-9","DOIUrl":"10.1007/s10035-024-01411-9","url":null,"abstract":"<div><p>Granular media is ubiquitous, playing a vital role in a diverse set of applications. The complex microstructure of granular media results from assorted particle shapes, morphologies, and packings, make it difficult to predict its macroscopic behavior. Under compression, these complex microstructures enable highly anisotropic and heterogenous behaviors, including creation of highly-loaded particles (i.e. force chains) supported by clusters of minimally-loaded particles. While many existing constitutive models relate state variables describing microscale behavior to continuum properties, these models do not generally consider the mesoscale interactions between the force chain network and minimally-loaded particles. Here, we develop a micromechanics model that connects micro-scale force chain mechanics to macro-scale mechanical behavior through explicit consideration of the interaction between force chains and minimally-loaded particles. We first examine the elastic behavior of a force chain using a spring model, explicitly considering the mesoscale interactions between the force-chains and surrounding regions. We then construct an equivalent inclusion problem to calculate macroscopic mechanical response as analytical functions of microscopic properties, with proper consideration of mesoscale interactions. We present our calibration and validation approaches, showing the model’s predictive abilities. Finally, we examine the effect of relevant microscopic quantities on macroscopic response, demonstrating the importance of these mesoscale interactions on bulk deviatoric behavior.</p></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"26 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140097790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simplified level set discrete element modeling of particle suspension flows in microfluidics: clogging statistics controlled by particle friction and shape 微流体中颗粒悬浮流的简化水平集离散元件建模：受颗粒摩擦力和形状控制的堵塞统计数据

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-03-09 DOI: 10.1007/s10035-024-01405-7

Ziran Zhou, Rigoberto Moncada, Nathan Jones, Jacinto Ulloa, Xiaojing Fu, José E. Andrade

{"title":"Simplified level set discrete element modeling of particle suspension flows in microfluidics: clogging statistics controlled by particle friction and shape","authors":"Ziran Zhou, Rigoberto Moncada, Nathan Jones, Jacinto Ulloa, Xiaojing Fu, José E. Andrade","doi":"10.1007/s10035-024-01405-7","DOIUrl":"10.1007/s10035-024-01405-7","url":null,"abstract":"<div><p>Particulate precipitation, deposition, and accumulation, including the formation of salt and mineral crystals, frequently occur in a wide range of subsurface applications involving multiphase flow through porous media. Consequently, there has been a considerable emphasis on researching and understanding these phenomena. However, modeling particle dynamics in flows through porous media with low Reynolds numbers has always been a challenging problem as it requires resolving fluid flow around the moving solid particles, the solid–solid contact mechanics, and the solid–fluid coupling. The discrete element method coupled with fluid solvers has been widely used to study particle-laden flow. Most fluid-solid numerical schemes involve solving the full or generalized Navier–Stokes equations, which often yields relatively accurate fluid-solid interactions at the cost of computation time and particle shape limitations. In this paper, we present a novel method to study mono-layered particle-laden flow by coupling the level set discrete element method (LS-DEM) with Hele-Shaw flow model. Utilizing the Hele-Shaw flow model allows us to simplify flow computation, while incorporating LS-DEM enables the simulation of arbitrarily shaped particles. Cases of mono-layered particle flow through a simplified micromodel geometry are studied and validated against published experimental results. Moreover, the effects of particle friction and shape on clogging statistics are investigated.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"26 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140098124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of free water on the quasi-static compression behavior of partially-saturated concrete with a fully coupled DEM/CFD approach 利用 DEM/CFD 全耦合方法分析自由水对部分饱和混凝土准静态压缩行为的影响

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-03-09 DOI: 10.1007/s10035-024-01409-3

M. Krzaczek, J. Tejchman, M. Nitka

{"title":"Effect of free water on the quasi-static compression behavior of partially-saturated concrete with a fully coupled DEM/CFD approach","authors":"M. Krzaczek, J. Tejchman, M. Nitka","doi":"10.1007/s10035-024-01409-3","DOIUrl":"10.1007/s10035-024-01409-3","url":null,"abstract":"<div><p>The work aims to numerically investigate the quasi-static response of partially fluid-saturated concrete under two-dimensional uniaxial compression at the mesoscale. We investigated how the impact of free pore fluid content (water and gas) affected the quasi-static strength of concrete. The totally and partially fluid-saturated concrete behavior was simulated using an improved pore-scale hydro-mechanical model based on DEM/CFD. The fluid flow concept was based on a fluid flow network made up of channels in a continuous region between discrete elements. A two-phase laminar fluid flow was postulated in partially saturated porous concrete with very low porosity. Position and volumes of pores/cracks were considered to correctly track the liquid/gas content. In both dry and wet conditions, a series of numerical simulations were performed on bonded granular specimens of a simplified spherical mesostructure that mimicked concrete. The effects of fluid saturation and fluid viscosity on concrete strength and fracture, and fluid pore pressures were investigated. It was found that each of those effects significantly impacted the hydro-mechanical behavior of concrete. Due to the rising fluid pressure in pores during initial specimen compaction under compressive loading that promoted a cracking process, the compressive strength increased as fluid saturation and fluid viscosity decreased.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div><div><p>DEM-CFD results for fully saturated specimen: evolution of maximum pore water pressure against vertical normal strain during uniaxial compression (from zero up to peak stress for).</p></div></div></figure></div></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"26 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140074273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of gradation range on strong contact network in granular materials 级配范围对颗粒材料中强接触网络的影响

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-03-06 DOI: 10.1007/s10035-024-01404-8

Ziyu Jin, Jiaying Liu, Honglei Sun, Miaomiao Sun, Xiaorong Xu

{"title":"Influence of gradation range on strong contact network in granular materials","authors":"Ziyu Jin, Jiaying Liu, Honglei Sun, Miaomiao Sun, Xiaorong Xu","doi":"10.1007/s10035-024-01404-8","DOIUrl":"10.1007/s10035-024-01404-8","url":null,"abstract":"<p>The topology of the granular material in the microscale affects the macroscale mechanical responses. Based on graph theory, the particles can be considered as nodes, and contacts can be considered as links, which form the contact network. Within the contact network, different force thresholds are applied to distinguish the strong and weak networks. This paper focuses on the influence of gradation range on the topological characterizations of the strong contact network in 2D granular materials. Biaxial shearing tests for 6 uniformly graded samples and 1 nonuniformly graded sample are conducted using the discrete element method. Network-based metrics are used to investigate the topology features of the strong contact network with different thresholds for three stress states. It is found that gradation range has little influence on the macroscale mechanical responses and the formation of shear bands for assemblies with different gradations (except for monodisperse assembly). Comparing the network-based metrics for samples with different gradations, only the differences in the value of the metrics are found while the strong networks exhibit a unique variation rule. The critical threshold appears at 1.4 times average contact force, which means the largest cluster can span the boundaries with minimum contacts in the strong contact system. The granular system loses the connections between the boundaries in the confining pressure direction at a smaller threshold compared to the loading direction, and the monodisperse assembly shows a particular topology compared to other samples.</p>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"26 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140048000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Frictional weakening of a granular sheared layer due to viscous rolling revealed by discrete element modeling 离散元建模揭示粘性滚动导致的粒状剪切层摩擦减弱

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-03-03 DOI: 10.1007/s10035-024-01407-5

Alexandre Sac-Morane, Manolis Veveakis, Hadrien Rattez

{"title":"Frictional weakening of a granular sheared layer due to viscous rolling revealed by discrete element modeling","authors":"Alexandre Sac-Morane, Manolis Veveakis, Hadrien Rattez","doi":"10.1007/s10035-024-01407-5","DOIUrl":"10.1007/s10035-024-01407-5","url":null,"abstract":"<div><p>Considering a 3D sheared granular layer through a discrete element modeling, it is well known the rolling resistance influences the macro friction coefficient. Even if the rolling resistance role has been deeply investigated previously because it is commonly used to represent the shape and the roughness of the grains, the rolling viscous damping coefficient is still not studied. This parameter is rarely used or only to dissipate the energy and to converge numerically. This paper revisits the physical role of those coefficients with a parametric study of the rolling friction and the rolling damping at different shear speeds and different confinement pressures. It has been observed the damping coefficient induces a frictional weakening. Indeed, competition between the rolling resistance and the rolling damping occurs. Angular resistance aims to avoid grains rolling, decreasing the difference between the angular velocities of grains. Whereas, angular damping acts in the opposite, avoiding a change in the difference between the angular velocities of grains. In consequence, grains stay rolling and the sample toughness decreases. This effect must be considered to not overestimate the frictional response of a granular layer.</p><h3>Graphic abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"26 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140025371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Performance and limits of a geotechnical centrifuge: DEM-LBM simulations of saturated granular column collapse 土工离心机的性能和极限：饱和颗粒柱坍塌的 DEM-LBM 模拟

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-03-01 DOI: 10.1007/s10035-024-01408-4

William Webb, Barbara Turnbull, Alessandro Leonardi

{"title":"Performance and limits of a geotechnical centrifuge: DEM-LBM simulations of saturated granular column collapse","authors":"William Webb, Barbara Turnbull, Alessandro Leonardi","doi":"10.1007/s10035-024-01408-4","DOIUrl":"10.1007/s10035-024-01408-4","url":null,"abstract":"<p>This study investigates the dynamics of granular flows in geotechnical centrifuge models, focusing on the effects of centrifugal and Coriolis accelerations. While conventional laboratory-scale investigations often rely on Froude scaling, geotechnical centrifuge modelling offers a unique advantage in incorporating stress-dependent processes that fundamentally shape flow rheology and dynamics. Using the Discrete Element Method (DEM) and the Lattice-Boltzmann Method (LBM), we simulate the collapse of a just-saturated granular column within a rotating reference frame. The model’s accuracy is validated against expected trends and physical experiments, demonstrating its strong performance in replicating idealised collapse behaviour. Acceleration effects on both macro- and grain-scale dynamics are examined through phase front and coordination number analysis, providing insight on how centrifugal and Coriolis accelerations influence flow structure and mobility. This work enhances our understanding of granular flow dynamics in geotechnical centrifuge models by introducing an interstitial pore fluid and considering multiple factors that influence flow behaviour over a wide parameter space.</p>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"26 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10035-024-01408-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140007802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Research on dust fugitive characteristics of mobile dust sources based on industrial bulk material transfer process 基于工业散装物料输送过程的移动尘源粉尘逃逸特性研究

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-03-01 DOI: 10.1007/s10035-024-01399-2

Hongfa Sun, Zhengyu Li, Jibo Long, Fang Ruan

{"title":"Research on dust fugitive characteristics of mobile dust sources based on industrial bulk material transfer process","authors":"Hongfa Sun, Zhengyu Li, Jibo Long, Fang Ruan","doi":"10.1007/s10035-024-01399-2","DOIUrl":"10.1007/s10035-024-01399-2","url":null,"abstract":"<div><p>The process of transferring and conveying bulk materials are common in industrial production, and the dust pollution is a problem of mobile dust sources due to the velocity of the dust source. Firstly, a physical model of mobile dust sources is established. Secondly, the accuracy of the pollution model is verified by the existing experimental data. Finally, the effects of dust source velocity, wind velocity and particle diameter on dust fugacity are analysed. The results show that the wind velocity has the greatest influence on dust diffusion, especially the wind velocity of 3 m/s; The influence of different dust source velocity on the spatial distribution of dust concentration mainly exists in the area near the mobile surface; For dust diameter less than 10μm, the diameter has little effect on dust diffusion. In order to describe the dust pollution situation, the dust initiation rate was defined to evaluate the dust intensity of each condition. The biggest influence is wind velocity. When the wind velocity is 0.5 m/s, the dust initiation rate is only 2.5 × 10<sup>−5</sup> s<sup>−1</sup>. When the wind velocity reaches 10 m/s, the dust initiation rate is 1.5 × 10<sup>−4</sup> s<sup>−1</sup>. The dust initiation rate increases with the velocity of mobile dust source. The results can provide theoretical basis for dust pollution control in the process of transporting industrial bulk materials.</p><h3>Graphic abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"26 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140018203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Plastic deformation effect on contact behaviour in granular materials 塑性变形对颗粒材料接触行为的影响

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-03-01 DOI: 10.1007/s10035-024-01394-7

F. N. Altuhafi, B. A. Baudet, M. R. Coop

引用次数: 0