Granular Matter最新文献

{"title":"A discrete particle model considering particle shape and its simulation study of isolated draw","authors":"Liancheng Wang,&nbsp;Anlin Shao,&nbsp;Fuming Qu,&nbsp;Xingfan Zhang,&nbsp;Xiaobo Liu","doi":"10.1007/s10035-025-01533-8","DOIUrl":"10.1007/s10035-025-01533-8","url":null,"abstract":"<div><p>The flow characteristics of granular materials under gravity represent the primary scientific challenge involved in caving mining. Conducting in-depth research in this area contributes to improving ore recovery results. This study introduces an innovative discrete particle dynamics model that combines the advantages of soft-sphere and hard-sphere algorithms to significantly improve the simulation of granular flow in caving mining. The proposed soft-hard sphere coupling model achieves remarkable computational efficiency while accurately capturing the influence of particle shape on flow behavior. By developing a specialized collision resolution algorithm and implementing advanced contact detection methods, the model successfully simulates the isolated draw process for particles of various shapes, including circular, polygonal and elliptical particles. The reliability of the model is thoroughly validated through comparison with physical experiments and theoretical models. Furthermore, the study demonstrates how the rolling resistance coefficient can effectively characterize particle shape effects in circular particle simulations, providing a practical approach to balance computational efficiency and accuracy. These developments offer valuable insights for optimizing ore recovery in caving mining operations. </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":"27 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073869","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}

{"title":"Experimental study on the combined influence of geogrid and rubber granules on the shear behavior of railway ballast","authors":"Zihan Yan,&nbsp;Jing Chen,&nbsp;Qihang Hu,&nbsp;Chang Li,&nbsp;Rui Gao","doi":"10.1007/s10035-025-01530-x","DOIUrl":"10.1007/s10035-025-01530-x","url":null,"abstract":"<div><p>Geogrid is one of the most widely used geoinclusions in railway engineering to improve the bearing capacity of ballasted tracks. However, its effectiveness in mitigating ballast degradation, recognized as the most critical engineering challenge, remains limited, particularly in the context of the increasing demand for faster and heavier haul transportation nowadays. Rubber granules (RG), manufactured from waste rubber tires, possess high energy-absorbing properties that dampen vibration, reducing the stresses on ballast particles and helping to prevent ballast degradation. In order to explore the practical methods to delay the degradation of ballast and improve the performance of track bed, in this study, a series of large-scale direct shear tests were conducted on ballast aggregates with different geogrid-inclusion conditions and various RG content to investigate the shear behavior and performance of ballast under different configurations. The results show that while the RG effectively reduces the breakage of ballast particles, it negatively impacts the development of shear strength in aggregates, with or without geogrid reinforcement. As RG content increases, ballast aggregate exhibits lower peak shear strength, smaller maximum volumetric dilation, and greater volumetric contraction during shearing. For geogrid-reinforced ballast, incorporating 5% rubber granules (by volume) results in a reduction of aggregate shear strength by approximately 12%, while simultaneously mitigating ballast breakage by more than 30%. By balancing the enhancement of ballast durability with the maintenance of adequate shear strength, a 5% RG content by volume is recommended as a suitable proportion for practical applications. Based on experimental observations, a set of empirical equations has been proposed to estimate the shear strength and volumetric deformation of geogrid-reinforced ballast in the presence of RG. The findings from this study provide valuable insights for improving the design and performance of ballasted railway tracks, particularly in addressing ballast degradation and ensuring track resilience under modern loading demands.</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":"27 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143949653","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}

{"title":"Quantitative analysis of sheared unsaturated wet granular materials using X-ray micro-tomography and advanced segmentation techniques","authors":"Ahmad Awdi,&nbsp;Camille Chateau,&nbsp;Abdoulaye Fall,&nbsp;Jean-Noël Roux,&nbsp;Patrick Aimedieu","doi":"10.1007/s10035-025-01518-7","DOIUrl":"10.1007/s10035-025-01518-7","url":null,"abstract":"<div><p>The microstructure of sheared unsaturated wet granular materials, comprising solid particles, liquid phases, and void spaces, is explored using X-ray micro-tomography. Advanced segmentation techniques are employed to overcome challenges in distinguishing phases within the material, utilizing a combination of Random Forest and U-Net models for accurate segmentation of the X-ray images. This methodology enables the quantification of the solid and liquid fractions within the sample, revealing the effects of shear deformation on their distribution. Additionally, an automated tool is designed to characterize the local geometry of small liquid domains, classified according to the number of connected liquid bridges joining grain pairs and the shape of such clusters. It is shown that deformation redistributes the liquid phase, which tends to be excluded from the strongly sheared regions. Coordination number estimates agree with published numerical simulation results. The study also addresses some limitations related to voxel size. The robust tools to analyse complex three-phase microstructure of wet granular materials are expected to improve the modeling of their rheology under different conditions.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div><div><p> \"Exploring the microstructure of sheared unsaturated wet granular materials using X-ray micro-tomography. Advanced segmentation with Random Forest and U-Net models enables quantitative analysis of liquid morphologies, after automatic classification, and their evolution under shear, revealing redistribution patterns and coordination changes</p></div></div></figure></div></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"27 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10035-025-01518-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143930101","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}

{"title":"Investigating the applicability of the state parameter-based scaling law for granular material using DEM","authors":"Qiang Ma,&nbsp;Yan-Guo Zhou,&nbsp;Xiao-Tian Yang,&nbsp;Kyohei Ueda,&nbsp;Yun-Min Chen","doi":"10.1007/s10035-025-01522-x","DOIUrl":"10.1007/s10035-025-01522-x","url":null,"abstract":"<div><p>Granular materials are typically state-dependent materials, with their strength and deformation behaviors being dependent on density and stress state. Although some studies have adopted the state parameter-based scaling law for application in model tests, their applicability has not been systematically investigated. This paper employs Discrete Element Method (DEM) to conduct drained and undrained monotonic triaxial tests, and undrained cyclic triaxial tests, to investigate the validity of Rocha’s assumption and applicability of the state parameter-based scaling law. The simulation results indicate that the state parameter-based scaling law is suitable for physical modeling of geotechnical problems that prioritize peak or instability strength. The state parameter can roughly determine the liquefaction resistance, supporting its applicability to soil liquefaction problems. However, to ensure the accuracy of the model tests, the overburden stress ratio between the prototype and the model should be chosen within 5 to 10 times.</p></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"27 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919036","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}

{"title":"Granular flow enhancement in a model silo by using a pedant mobile obstacle","authors":"A. Yamil Sirur Flores,&nbsp;Jesica G. Benito,&nbsp;Rodolfo O. Uñac,&nbsp;Irene Ippolito,&nbsp;Luc Oger,&nbsp;Ana M. Vidales","doi":"10.1007/s10035-025-01528-5","DOIUrl":"10.1007/s10035-025-01528-5","url":null,"abstract":"<div><p>It is well established that placing an obstacle near a silo outlet reduces the clogging probability in systems approaching the jamming zone, even enhancing the flow rate when the obstacle is optimally positioned. Typically, studies have focused on fixed obstacles in 2D-silo models, using spherical particles, and the underlying mechanisms driving flow rate improvements remain a topic of ongoing research. We investigate experimentally the impact of a pendant mobile obstacle on the discharge flow of lentils using a rectangular flat-bottomed silo with a thickness of several particles. Even when the silo is inside the continuous flow regime, we still observe flow maximization for an optimal obstacle height. By selecting appropriate scaling lengths, we achieve a collapse of the flow rate curves for all aperture sizes studied. Our results indicate that different silo configurations exhibit distinct flow correlations, whose type and extent are crucial for flow rate maximization. Velocity profiles indicate that the obstacle increases particle velocity in the lateral channels surrounding the obstacle. Beyond the optimal height, this effect diminishes, and a sharp drop in velocity is found. This is the first experimental confirmation of previous numerical studies. An analytical model using free-fall particle behavior to describe the flow in the lateral channels provides a good representation of the discharge rate.</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":"27 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143908696","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}

{"title":"Induced collective response in sheared granular faults exhibiting stick–slip","authors":"Zhuan Dai,&nbsp;Ke Gao","doi":"10.1007/s10035-025-01525-8","DOIUrl":"10.1007/s10035-025-01525-8","url":null,"abstract":"<div><p>Granular gouge is commonplace in natural faults. Revealing the particle motion and rearrangement inside the granular gouge during stick–slip cycles can help better understand the complex processes involved in tectonic earthquakes. Here, the microscopic kinematics and collective response of a granular gouge during the two distinctive states—stick and slip phases—are analyzed based on a numerically simulated sheared granular fault system using the combined finite-discrete element method. During stick phases, the gouge locks the fault plane like a solid, but a few tiny active particle clusters exist due to scattered local contact failures between particles. When slips occur, part of the gouge flows like a liquid, and the particles in the principal slip zone are the most chaotic. The correlation of the collective response of granular particles is weak during stick phases, and the particles barely rearrange themselves, which gives opportunities for storing potential energy in the system. However, when fault slips, the gouge particles’ collective response is strongly correlated, and the stored energy is released, indicating that the particles are effectively rearranged. The rearrangement of the gouge can be explained by the stress chain structures. These stress chains facilitate the cascade of the slips, which reveals why granular gouge inhibits pre-slips. Our study shows how the granular gouge reacts and rearranges during stick–slip cycles from a microscopic viewpoint and may shed light on the dynamic nucleation process of natural earthquakes.</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":"27 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143892715","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}

{"title":"Shape properties validation of virtual 3D particles created from AIMS 2D images for railway ballast DEM modeling","authors":"Daianne Fernandes Diógenes,&nbsp;Renan Santos Maia,&nbsp;Manoel Porfírio Cordão Neto,&nbsp;Roberto Luis Roselló Valera,&nbsp;Márcio Muniz de Farias,&nbsp;Carlos Alexander Recarey-Morfa,&nbsp;Verônica Teixeira Franco Castelo Branco","doi":"10.1007/s10035-025-01526-7","DOIUrl":"10.1007/s10035-025-01526-7","url":null,"abstract":"<div><p>Laboratory-scale research on railway ballast often fails to produce parameters reflecting real-world conditions, while real-scale research incurs high costs. Advancements in computational capacity allowed for discrete element method (DEM) to simulate ballast behavior with three-dimensional, irregularly shaped particles. This research focuses on developing virtual 3D particles for DEM based on digital image processing (DIP) from the use of the Aggregate Imaging Measurement System (AIMS). This can potentially provide a rationale for taking full advantage of databases of aggregate properties obtained with this equipment over more than a decade across various regions worldwide. Quarry-produced aggregates were characterized in terms of shape properties in three orthogonal positions using AIMS. Virtual 3D particles were generated from one, two, or three real 2D images, with strong correlations between real and virtual particles results obtained for sphericity, flatness, elongation, and flatness/elongation ratio. This study shows that generating virtual 3D particles from one single real 2D image from AIMS is an effective and time-efficient process. Furthermore, shape properties classification of virtual particles closely matched real ones, with minimal variation near classification boundaries, confirming the method’s consistency. This approach can be an alternative to more computationally expensive 3D modeling, as well as allowing for the virtual reproduction of aggregates not locally available by sharing AIMS databases. Finally, numerical simulations were proven to be sensitive to real particle shapes, allowing for better understanding of ballast performance, leading to optimization of maintenance and reducing track wear and elements’ failure.</p></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"27 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871426","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}

{"title":"Study on stress dips in granite residual soil based on experiments and DEM","authors":"Junsheng Chen,&nbsp;Bochao Zhang,&nbsp;Lingfeng Guo,&nbsp;Heng Zhang,&nbsp;Martin Achmus,&nbsp;Michael Beer","doi":"10.1007/s10035-025-01523-w","DOIUrl":"10.1007/s10035-025-01523-w","url":null,"abstract":"<div><p>The stress dip, a local minimum in the vertical stress distribution beneath granular piles, has captured the interest of many researchers. Studying stress dips in granite residual soil is of critical importance due to its relevance to engineering projects, soil mechanics, and particle behaviors. The purpose of this study is to confirm the existence of the stress dip in granite residual soil and explore its evolution during accumulation. In this work, granite residual soil conical piles were formed by the localized source piling method in experiments. During the experiment, Teflon film was placed below the piles to hinder the formation of stress dips, while the vertical stress distribution beneath each pile at varying heights was measured to monitor the evolution of stress dips. Besides, DEM simulations were employed to analyze the formation and evolution mechanism of the stress dips. The experimental and simulation results showed that stress dips can be formed in granite residual soil piles, occurring both in the center and locally. Stress dips evolve gradually through accumulation rather than being intrinsic properties of the piles. From a spatial perspective, no clear pattern is observed in the location of the stress dips. Quantitatively, as pile size increases, stress dips become more prevalent throughout the entire scope, although individual dips may dissipate. The normalized analysis of the central stress dip suggests that the normalized stress distribution pattern of the central stress dip is independent of pile size. The formation and evolution of stress dips are influenced by the force chain network, which consists of arch and ring force chains that are promoted by the supporting effect of the base plate and the particle squeezing effect.</p></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"27 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143840283","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}

{"title":"Statistics for simulated assemblies of particles from mathematical models","authors":"Felix Ballani,&nbsp;Dietrich Stoyan","doi":"10.1007/s10035-025-01519-6","DOIUrl":"10.1007/s10035-025-01519-6","url":null,"abstract":"<div><p>This study examines particle statistics using simulated particle assemblies derived from mathematical models. This approach serves as a complement to investigations that analyze samples of real particles to assess the accuracy of measurement and statistical methods. Three mathematical particle models, all based on tessellations of three-dimensional space, including the well-known Voronoi tessellation, are employed to generate random convex polyhedra. A key advantage of this approach is that the true statistical properties of the particles and particle assemblies are well understood, allowing for a realistic evaluation of statistical methods. Furthermore, the analyses performed can be easily replicated or verified by other researchers in parallel studies. The approach is applied to the evaluation of two commonly used statistical methods: estimating the volume-weighted particle size distribution function from image analysis data, and estimating the specific surface area when particle volumes are measured. The simulation results indicate that image analysis methods yield accurate results for particle size distributions. Additionally, estimating the specific surface area using particle size distributions produces acceptable results when incorporating the mean sphericity of the aggregates, without accounting for particle roughness, which is not a significant factor for the particles under consideration.</p></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"27 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143821915","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}

{"title":"Experimental investigation on breakage characteristics of feed particle beds by uniaxial compression","authors":"Xianrui Kong,&nbsp;Qing Cao,&nbsp;Ganwen Yong,&nbsp;Shanchen Jiang,&nbsp;Zhiyou Niu","doi":"10.1007/s10035-025-01520-z","DOIUrl":"10.1007/s10035-025-01520-z","url":null,"abstract":"<div><p>To investigate the breakage characteristics of particle groups, the particle bed compression tests were conducted with feed groups. Three compression stages were determined based on the force–displacement curves of feed pellets with different aspect ratios. The occurrence of the stage ascent curve was explained by the microstructure of the feed pellet and the filling of pores in the particle bed. The influence of aspect ratio and moisture content on the mass-specific compressive energy was investigated, revealing that the energy increased with the increase of aspect ratio and water content. Additionally, the impact of these factors on the pulverization rate was assessed, demonstrating that the pulverization rate rises with the aspect ratio but diminishes with water content. The PSD (particle size distribution) of the feed pellet after compression was fitted with the Weibull function. The R² values are higher than 0.97 and 0.93 for different aspect ratios and water content, respectively. Furthermore, new models were established to represent the PSD, taking aspect ratio and water content into consideration. The R² values are higher than 0.95 and 0.96, respectively. These findings enhance the understanding of breakage characteristics of feed pellets under compression and provide a theoretical model for quality assessment of agricultural products.</p></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"27 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143793203","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}