Granular Matter最新文献

{"title":"Mechanically driven particles as simple models for silo discharge, collective behavior of animate beings, and human egress dynamics","authors":"Ralf Stannarius,&nbsp;Tina Hanselka,&nbsp;Torsten Trittel","doi":"10.1007/s10035-026-01631-1","DOIUrl":"10.1007/s10035-026-01631-1","url":null,"abstract":"<div><p>The collective behavior of large ensembles of interacting dynamic objects is an ubiquitous phenomenon that is still not fully understood even today. For example, passages through bottlenecks are often crucial situations that may delay or inhibit the motion of particles, animals, humans, or vehicles. It is often difficult to obtain experimental data under systematic parameter variations, particularly when biological objects are involved. We introduce here purely mechanical experiments with symmetrically and asymmetrically shaped particles that are excited by a vibrating horizontal ground plate. Active and passive dynamics can be mimicked by proper adjustment of the weight distributions in the particles, and the level of activity can be controlled by excitation parameters. A slight tilt of the ground plate can simulate drag in a preferential direction. All these parameters can be conveniently varied in this kitchen-table experiment and optical particle tracking yields all relevant information for a statistical analysis.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div><div><p>Active (blue-white) and passive (reddish) objects on a vibrating table showing spontaneous segregation. Left: initial state, right: after 5 minutes of shaking. </p></div></div></figure></div></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"28 2","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10035-026-01631-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147561606","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":"Thermal DEM study of heat transfer and flow patterns of fine cohesive particles under vertical vibration","authors":"Dongdong Fang,&nbsp;Xiaotian Li,&nbsp;Xiaobin Zhan,&nbsp;Xiwen Li","doi":"10.1007/s10035-026-01634-y","DOIUrl":"10.1007/s10035-026-01634-y","url":null,"abstract":"<div><p>Vertical vibration is an effective technique for enhancing the thermal performance of granular systems; however, a quantitative understanding of its influence on cohesive media is still limited. This study employs the thermal discrete element method (DEM) to investigate the heat transfer and flow dynamics of cohesive particles in a vertically vibrated container. A bond number scaling strategy is adopted to capture the characteristic behaviors of fine powders. The results demonstrated that while vibration slightly reduced the overall heating rate compared to a stationary system, it significantly enhanced temperature uniformity by transitioning the heat transfer mode from conduction to convective mixing. The relationship between vibration parameters and thermal performance was found to be non-monotonic. An optimal dimensionless vibration intensity (<span>(Gamma approx 138)</span>) was identified, which maximized heating efficiency. Furthermore, a critical range of dimensionless amplitude (<span>(0.17&lt;Ar&lt;0.27)</span>) marked the transition to full fluidization. Regarding cohesion, moderate surface energy stabilized the fluidized bed, whereas excessive cohesion overwhelmed the vibrational input, causing re-agglomeration. Finally, a unified dimensionless framework was proposed, revealing that the thermal flow regime was governed by the competition between vibrational intensity and the bond number. These findings provide theoretical insights for optimizing the processing of cohesive granular materials. </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":"28 2","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147561605","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":"A numerical method incorporating the improved liquid bridge model into DEM for simulating the behaviors of wet granular materials","authors":"Zi-Ye Wang,&nbsp;Yong Tan","doi":"10.1007/s10035-026-01625-z","DOIUrl":"10.1007/s10035-026-01625-z","url":null,"abstract":"<div><p>Liquid bridge force plays an important role in geology and behavior of wet granular materials. At present, many discrete-element-method (DEM) numerical models involving liquid bridges have been developed, but few of them were capable of characterizing liquid bridges comprehensively. In addition, these models usually neglected surface roughness of spheres, leading to overestimation of liquid bridge force. In this study, an analytical expression of liquid bridge force between two unequal-sized spheres in contact when the liquid bridge volume tends to zero was derived. It showed that a large liquid bridge force could be induced by an extremely small liquid volume, resulting in overestimation of liquid bridge force under nearly dry condition. To solve this problem, the scheme of an improved liquid bridge model (ILBM) incorporating roughness coefficient was proposed first. Subsequently, a numerical method incorporating ILBM into DEM was developed. The developed method can calculate liquid bridge forces accurately and encompasses all the parameters of liquid bridges. Furthermore, it avoids unreasonable liquid bridge force under extremely small liquid bridge volume and considers the formation and rupture of liquid bridges. The accuracy and reliability of the developed method were validated by axial compression tests. Finally, the evolution of number of liquid bridges, coordination number, and liquid bridge force during the axial compression tests were analyzed and the discrepancy between numerical and experimental results was discussed.</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":"28 2","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147561198","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":"Interaction of regular non-spherical particles with rigid barrier in gravity-driven dry granular flow","authors":"Prity Dhanai,&nbsp;Debayan Bhattacharya","doi":"10.1007/s10035-026-01621-3","DOIUrl":"10.1007/s10035-026-01621-3","url":null,"abstract":"<div><p>Gravity-driven granular flow, viz. landslides, debris flow, etc., poses a severe threat to infrastructure and communities, making it crucial to understand their dynamics and interaction with mitigation measures. This study adopts the Discrete Element Method (DEM) to systematically examine how particle shape influences dry granular flow kinematics and impact force on rigid barriers in an inclined channelized frictional flume. The DEM model is first benchmarked against an experimental study using spherical particles and then extended to regular non-spherical shapes, including ellipsoid, cylinder, dodecahedron, octahedron, and tetrahedron, characterized by various sphericity measures available in the literature. Our findings reveal that decreasing particle sphericity significantly enhances flow resistance, attributed to an increased number of interparticle contacts, thereby leading to reduced macroscopic responses, viz., frontal velocity, kinetic energy, and peak impact force. Furthermore, the presence of secondary flows and granular temperature is found to be more pronounced for particles with higher sphericity. Flow conditions derived from the DEM simulations are used to parameterize analytical force models. Analysis of the widely used depth-averaged hydrodynamic continuum model reveals a negative correlation between the dynamic pressure coefficient (<span>(k_d)</span>) and Froude number (<i>Fr</i>), driven by particle shape-induced changes in flow depth and velocity. Further, a modified depth-averaged continuum model has been utilized to distinguish the dynamic contribution of the incoming flow from the static component associated with the dead zone, demonstrating that non-spherical particles significantly augment the dynamic force fraction during impact. These insights contribute to improved understanding and design of mitigation structures for gravity-driven granular flow.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div><div><p>Particle shape effect on dry granular flow</p></div></div></figure></div></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"28 2","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147559998","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":"Dust transport and diffusion under individual and coupled dust source conditions in a fully mechanized coal mining face","authors":"Yongbo CAI,&nbsp;Bingqian Yan,&nbsp;Chunyang Zhang,&nbsp;Yingjie Liu,&nbsp;Zuo Sun,&nbsp;Chao Xu,&nbsp;Chi Li,&nbsp;Xiaoyu Zhang","doi":"10.1007/s10035-026-01623-1","DOIUrl":"10.1007/s10035-026-01623-1","url":null,"abstract":"<div>\u0000 \u0000 <p>To investigate the dust transport patterns under different dust sources and their coupling conditions in fully mechanized mining faces, this study focuses on the 2–2 mining face at Xinjie Taigemiao mine. Using Fluent software, we investigate how the distribution of dust concentration on the coal face under different sources: shearer coal-cutting, hydraulic support movement, air intake, and their coupled effects. Results indicate that dust transport within the roadway is primarily governed by obstacles and airflow. The face wind velocity exhibits an overall low-high-low fluctuation pattern along the longitudinal direction. Dust-dense zones vary across different sources: cutting dust concentrates near the drums due to machine obstruction, while dust from support movement clusters near the pedestrian side. Air intake dust disperses uniformly throughout the mining face cross-section. Under the coupled dust source condition, dust concentration exceeds single-source levels with a pronounced additive effect. The maximum local dust concentration reached 2540.2 mg/m³. The research findings effectively elucidate the dust transport and dispersion patterns in fully mechanized mining faces under varying dust source conditions, providing valuable reference for dust control layout in mining faces.</p>\u0000 </div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"28 2","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147559996","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":"A probabilistic characterization method for 3D ballast profiles and the influence of ballast profiles on ballast bed","authors":"Kai Liu,&nbsp;Jia-yan Nie,&nbsp;Rong Chen,&nbsp;Zi-jun Cao,&nbsp;Jian-xing Liu,&nbsp;Ping Wang","doi":"10.1007/s10035-026-01628-w","DOIUrl":"10.1007/s10035-026-01628-w","url":null,"abstract":"<div><p>The profile is a crucial characteristic of a ballast particle. It is important to characterize the uncertainties of three-dimensional ballast particle profiles and to determine the effects of these profiles on the dynamic performance of ballast bed. In this study, the spherical harmonics method was employed to achieve efficient reconstruction of the three-dimensional profiles of 300 ballast particles, which were obtained by performing indoor scanning. The relationships between elongated or flaky particles and the various orders of spherical harmonics functions were proven. The findings demonstrate that, when the spherical harmonics order exceeded 15, the errors in the volume, surface area and sphericity of the reconstructed particles were less than 5% compared to real particles. Furthermore, the spherical harmonics spectra approximately conformed to a gamma distribution, for which the average coefficient of determination (<span>({R}^{2})</span>) was 0.95. The second order relative spherical harmonics frequency significantly influenced the major ballast shape, which was considered to be cubic when this frequency was less than 0.17. Then, by utilizing the Nataf transformation, a joint probability density function of the spherical harmonics frequencies was established, which enabled probabilistic characterization and rapid random generation of the 3D profiles of ballast particles. Direct shear tests revealed that the proposed model exhibited an error of only 3%; in contrast, models that employed spherical particles or single type particles showed substantially higher errors that could reach 66%. Finally, a ballast bed was developed to analyze the effects of elongated and flaky particles on the lateral resistance of ballast bed and the sleeper acceleration receptance. The results indicated that the lateral resistance could increase by up to 30% as the proportions of elongated and flaky particles increased, while the sleeper acceleration receptance below 500 Hz not changed.</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":"28 2","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147441541","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 influence of grain size distribution, initial water content, and particle shape on the vibration-induced segregation in granular materials","authors":"Zahia Makkeb,&nbsp;Robert P. Chapuis,&nbsp;Djaouida Chenaf","doi":"10.1007/s10035-026-01630-2","DOIUrl":"10.1007/s10035-026-01630-2","url":null,"abstract":"<div><p>This study investigates the influence of grain size distribution (GSD), initial water content (<i>w</i>_i), and aggregates shape on the segregation behavior of granular materials subjected to vertical vibration. A series of controlled laboratory experiments was conducted using twelve different GSDs at initial moisture contents ranging from 0 to 10%. The results show that both the extent and continuity of the GSD significantly affect the occurrence of water upwelling and segregation of solids. Sub-rounded aggregates exhibit higher levels of segregation than sub-angular aggregates. Water content plays a dual role: increasing moisture reduces segregation up to an optimal saturation threshold, beyond which segregation increases again. No water migration was observed when the maximum particle size (<i>D</i>_max) was less than 2.5 mm, and the fines content (<i>D</i> &lt; 0.08 mm) remained below 10%. However, materials with discontinuous gradations and fines contents exceeding 10% exhibited upward migration of fines and localized liquefaction when the degree of saturation exceeded 50%. The findings also highlight the critical role of the intermediate particle fraction (0.08 mm &lt; <i>D</i> &lt; 5 mm) in controlling saturation variations, beyond the influence of the coarsest and fines fractions. Although restrictive grain size specifications can help limit segregation, the study emphasizes the need for appropriate construction practices and compaction methods to maintain homogeneity in granular layers.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div><div><p>Graphical abstract</p></div></div></figure></div></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"28 2","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147441826","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":"Rate-dependent and moisture-sensitive mechanical behaviour of granular soils","authors":"Ranveer Singh Rathore,&nbsp;Tanusree Chakraborty,&nbsp;Venkitanarayanan Parameswaran","doi":"10.1007/s10035-026-01627-x","DOIUrl":"10.1007/s10035-026-01627-x","url":null,"abstract":"<div><p>This research examines the quasi-static and high-strain-rate characteristics of granular soil types: crushed and natural sands with a siliceous nature, using the Triaxial and Split Hopkinson Pressure Bar (SHPB) methods, respectively. The effects of particle shape, gradation, moisture content of sand, and loading strain rate on mechanical response pre-and post-breakage have been extensively investigated. The results from the current study demonstrated that natural sand possessed superior strength, attributed to its well-graded distribution and effective particle interlocking, whereas crushed sand exhibited lower strength and failure attributed to its angular particles and inadequate packing. Natural sand, which is characterised by its finer grains and higher density, exhibited improved energy absorption and strain rate sensitivity. The effect of moisture content varied across the sands, influencing compressibility and peak strength based on saturation levels and incident pressure. Scanning electron micrograph results pre-post breakage showed that particle shape and gradation of the sands strongly affect the break and evolve under dynamic load. The findings from the current work provide valuable insights for the response of granular materials subjected to extreme loading under man-made and natural disasters.</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":"28 2","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147441300","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":"Effects of cementing solution parameters on the mechanical properties and microstructural mechanisms of biocemented granite residual soil","authors":"Jian Ouyang,&nbsp;Yongjie Zhang,&nbsp;Junren Deng,&nbsp;Jiejin Chen,&nbsp;Yang Li,&nbsp;Cuiping Yi","doi":"10.1007/s10035-026-01624-0","DOIUrl":"10.1007/s10035-026-01624-0","url":null,"abstract":"<div><p>Granite residual soil is widely distributed in southern China, with high permeability, large porosity, and weak cementation. It is highly susceptible to erosion and landslides under heavy rainfall conditions. To enhance the mechanical properties of biocemented granite residual soil, laboratory tests were conducted to investigate the effects of various cementing solution parameters. Different grouting volumes, concentrations, and cycles of biocementation are compared in this study. Results indicated that high single-grouting volumes and high concentrations impeded the improvement of mechanical properties, while increasing the number of cycles was much more effective. Grouting volume was determined to be 1.05–1.2 times of porosity with a concentration of about 1.0 mol/L. Biocemented granite residual soil mainly gained increased shear strength through the increase of cohesive strength, while the internal friction angle played a minor role. The micro- and meso-pores dominated in the evolution of porosity, and its repair effectively influenced the mechanical properties. Moreover, filling pores and cementation of the soil particles improved the loose, porous, and weak bonding state of the soil. Improvement in mechanical properties could be considered varied and caused by the bridging effect, agglomeration, and coating at the microstructural interfaces. Vaterite formed under high solution concentrations and large injection volumes is prone to transformation into calcite, and the volumetric shrinkage associated with this phase transition leads to a deterioration in mechanical performance. This study offers valuable insights into the mechanisms and effectiveness of improving the mechanical properties of biocemented granite residual soil.</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":"28 2","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147363245","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":"Robot excavation and manipulation of geometrically cohesive granular media","authors":"Laura K. Treers,&nbsp;Daniel Soto,&nbsp;Joonha Hwang,&nbsp;Michael A. D. Goodisman,&nbsp;Daniel I. Goldman","doi":"10.1007/s10035-025-01597-6","DOIUrl":"10.1007/s10035-025-01597-6","url":null,"abstract":"<div>\u0000 \u0000 <p>Robots capable of manipulating cohesive materials would be beneficial in a variety of complex construction tasks. To discover principles by which robotic systems can effectively manipulate entangled granular media, we develop a robophysical platform for interaction with media composed of u-shaped particles. This robotic platform uses environmental signals to autonomously coordinate excavation, transport, and deposition of material. We test the effect of material initial conditions by characterizing robot performance in two different material compaction states, and observe as much as a 75% change in transported mass depending on initial material compressive loading. This large difference suggests the functional role that properties such as packing and geometric cohesion play in excavation and manipulation. To better understand these properties, we develop an apparatus for tensile testing of the geometrically cohesive media, which reveals how entangled material strength depends strongly on initial compressive loading. These results rationalize the variation observed in robotic performance and point to future directions for better understanding robotic interaction with entangled materials.</p>\u0000 </div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"28 2","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10035-025-01597-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147342379","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}