Granular Matter最新文献

{"title":"Universal laws in silo discharge of soft disks","authors":"Francisco J. Castro,&nbsp;Stefan Radl","doi":"10.1007/s10035-025-01527-6","DOIUrl":"10.1007/s10035-025-01527-6","url":null,"abstract":"<div><p>We investigate the effect of particle deformability on the flow behavior in a 2D silo. We use a novel Smoothed Particle Hydrodynamics-Discrete Element Method (SPH-DEM) approach that explicitly models the particles’ deformation. We identify a two-fold mechanism through which particle deformation influences silo flow: (i) the spatial arrangement of particles and (ii) the velocity distribution of particles at the outlet. Specifically, we observe—for orifices larger than five times the particle diameter—that the velocities at the outlet follow the same distribution for both hard and soft particles. Thus, we are able to collapse appropriately scaled velocity profiles at the outlet onto a single master curve. Also, we find that our velocity scaling should take the different spatial organization of soft and hard particles near the orifice into account. Finally, we explore the effect of particle deformation on the silo discharge rate. By introducing a deformability parameter <span>(alpha )</span>, we propose an extended version of the Beverloo equation that accounts for the influence of particle deformation on the flow rate. Interestingly, we find that this deformability parameter should be chosen as the ratio of the stress at the bottom of the container and the bulk modulus of the material.</p></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"27 3","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145162393","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":"Microscopic mechanism of basal stress fluctuation in rock-ice avalanche","authors":"Zhibo Dong,&nbsp;Zhiping Sun","doi":"10.1007/s10035-025-01538-3","DOIUrl":"10.1007/s10035-025-01538-3","url":null,"abstract":"<div><p>As a kind of geophysical flow in high and cold region, rock-ice avalanches increase in volume and potential impact by eroding and entraining bed material during their movement, thereby posing significant risks to human lives and infrastructure located downstream. This granular process is regulated by the basal stress and its variations at the flow-bed interface. It is imperative to offer a comprehensive understanding of the basal stresses produced by granular flows in order to enhance hazard risk management strategies. In this study, we conducted a series of discrete element method (DEM) simulations of rock-ice avalanches under steady-state conditions to enhance our microscopic understanding of particle-bed interactions. The quantitative indices of basal stress fluctuation, specifically the maximum stress and the standard deviation of stress, as well as the microscopic indices of particle interaction, including the Savage number, granular temperature, and particle free space, are assessed through numerical simulation. The results indicate that as the Savage number increases, the mode of particle interaction with the bed shifts from continuous contact to random collisions, leading to significant fluctuations in basal stress. Furthermore, variations in stress fluctuation are correlated with granular temperature, indicating a dependence on random motion of particles. In conclusion, a microscopic mechanism underlying stress fluctuations is proposed based on particle dynamics. As the macroscopic flow intensifies, the available free space surrounding the particles increases, resulting in an elevated local velocity due to the random motion of the particles, which generate a greater impact force on the bed.</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":2.9,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145162109","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":"Crescent-shaped attractor of barchan dunes and their influencing factors: a downsized experimental investigation","authors":"Bin Yang,&nbsp;Yu Fu,&nbsp;Yuanwei Lin,&nbsp;Yang Zhang,&nbsp;Jianjun Qu","doi":"10.1007/s10035-025-01545-4","DOIUrl":"10.1007/s10035-025-01545-4","url":null,"abstract":"<div><p>This study investigates the evolution of downsized barchan dunes in a water tunnel experiment, emphasizing the influence of inflow velocity on their crescent-shaped attractor. Based on image processing methods, the kinematic and morphological features of barchan dune evolution are determined. The results reveal that the varying inflow velocity will affect the crescent-shaped attractor. Furthermore, a cubic relationship is established between flow velocity and the aspect ratio of barchan dunes. Additionally, there is a morphological threshold in the evolution of the crescent-shaped attractor to evaluate its stability. This study highlights the sensitivity of the crescent-shaped attractor to inflow velocity and confirms its steady evolutionary pattern, and it provides a new perspective on the formation of the barchan dune swarms in the field of wind-blown sand dynamics.</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":2.9,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145160959","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 method for identifying fragmentation of open-pit mining blasting based on a new hybrid convolutional neural network","authors":"Jianyang Yu,&nbsp;Lingyu Meng,&nbsp;Shijie Ren,&nbsp;Xubin Song,&nbsp;Hongzhi Liang,&nbsp;Jiachen Cao,&nbsp;Yanping Xue,&nbsp;Wangbin Zhou","doi":"10.1007/s10035-025-01542-7","DOIUrl":"10.1007/s10035-025-01542-7","url":null,"abstract":"<div><p>The distribution of rock fragmentation after blasting is an important indicator for assessing the effectiveness of mine blasting. The quantitative characterization of blasting fragmentation is a challenging problem for the evaluation of blasting effects. The use of U-Net network technology to segment blasting images provides a new means for obtaining quantitative statistics from blasting fragmentation. Although the U-Net network is generally capable of segmenting images, there are issues in improving the accuracy and efficiency for ores. To solve these problems, this paper proposes a new network structure - ResOreNet. ResOreNet first integrates the Feature-Fusion module into the U-Net network to become a FU-Net network that enhances the model’s identification of target locations and morphological details, thereby improving the accuracy of ore image segmentation. More specifically, it incorporates the residual network into the FU-Net network, which effectively solves the phenomenon of blurring the boundary of the mineral rock image segmentation caused by the overfitting of the model, and the introduction of the residual network effectively mitigates the problem of the gradient vanishing of the loss function during the backpropagation, and also further improves the computational efficiency of the model, and provide a new technical means for obtaining evaluation indicators of blasting effects in mines.</p></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"27 3","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145160899","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 rheological model for loose sands with insights from DEM","authors":"Ming Yang,&nbsp;Giuseppe Buscarnera","doi":"10.1007/s10035-025-01532-9","DOIUrl":"10.1007/s10035-025-01532-9","url":null,"abstract":"<div><p>A rheological model for loose granular media is developed to capture both solid-like and fluid-like responses during shearing. The proposed model is built by following the mathematical structure of an extended Kelvin–Voigt model, where an elastic spring and plastic slider act in parallel to a viscous damper. This arrangement requires the partition of the total stress into rate-independent and rate-dependent stress components. To model the solid-like behavior, a simple frictional plasticity model is adopted without modifications, thus contributing to the rate-independent stress. Instead, the fluid-like or rate-dependent stress is further decomposed into deviatoric and volumetric parts, by proposing a new formulation based on a combination of the <span>(mu (I))</span> relation, originally developed under pressure-controlled shear, with a pressure-shear rate relation derived under volume-controlled shear. The proposed formulation allows the model to capture both the increase in the friction coefficient and the enhanced dilation at high shear rates. High-fidelity simulation data, obtained from discrete element method and multiscale modelling, are used to evaluate the performance of the proposed constitutive model. The model provides accurate results under both drained and undrained simple shear paths across a wide range of shear rates. Furthermore, it successfully reproduces at much lower computational cost the flowslide mobility computed through multiscale simulations, which is primarily regulated by the shear rate dependence of the material properties during the dynamic runout stage.</p></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"27 3","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10035-025-01532-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145171696","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":"DEM study of polydispersity and heat transfer in a bladed mixer","authors":"Umair Rafiq,&nbsp;Muhammad Shafiq Siraj,&nbsp;Daniyal Ahsen Awan","doi":"10.1007/s10035-025-01537-4","DOIUrl":"10.1007/s10035-025-01537-4","url":null,"abstract":"<div><p>Mixing performance and heat transfer was investigated in dry granular flows in cylindrical geometry where heat is transferred from cylindrical walls to granular bed. The discrete element method (DEM) was used to simulate these flows and to investigate the effect of different parameters on mixing and heat transfer that include impeller speed, blade rake angle, number of blades and polydispersity. The effect of impeller rotation on heat transfer was also investigated. Mixing quantification was done by using the latest subdomain mixing index (SMI). Results of DEM simulations for these parameters were concluded for mono and poly-dispersed flows. Velocity and heat transfer profiles were drawn. Better mixing was observed in the case of four blades. Higher impeller speed also showed better mixing and heat transfer. In this study, the effect of polydispersity—an often-overlooked factor—is studied. In all cases it was observed that polydispersity had a negative effect on both mixing and heat transfer due to enhanced segregation and reduced thermal conduction. It is also the first-of-its-kind analysis of coupled impeller-geometry effects on particulate mixing and thermal transport in granular media.</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":2.9,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145170654","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":"Research of island-less bowl vibratory finishing: container motion and granular media behavior","authors":"Yan Zhang,&nbsp;Wenhui Li,&nbsp;Xiuhong Li,&nbsp;Liaoyuan Zhang,&nbsp;Shengqiang Yang","doi":"10.1007/s10035-025-01534-7","DOIUrl":"10.1007/s10035-025-01534-7","url":null,"abstract":"<div><p>Vibratory finishing is widely used in aerospace, weapon industry, high-grade computer numerical control machine tools, rail transportation equipment, and other high-end equipment manufacturing industries. Processing parameters are critical to processing efficiency and processing effect. Island-less bowl vibratory finishing equipment is commonly used to process medium and large disk parts. Compared with traditional bowl vibratory finishing equipment, the lack of an island structure in the shape of the container and the low motor mounting position can lead to changes in the container motion and the flow field of the particulate medium. In this work, a bowl vibratory finishing mathematical model and numerical model were established, the velocity of the granular media at different locations in the container and the magnitude of the force was analyzed, the change rule of the container amplitude size, granular media motion characteristics and force behavior under different processing parameters was elucidated, the container amplitude test experiments and the force test experiments were carried out. The results show that during bowl vibratory finishing, the container performs periodic three-dimensional elliptical motion in space. The lack of island structure in island-less bowl vibratory finishing results in lower motion speed and frequency of the granular media in areas far away from the container wall. The granular media makes a spiral motion around the container’s central axis consisting of circular and tumbling motions in an extended period and performs irregular velocity-changing annular spiral motion in a short period. The phase difference will change the motion direction of the granular media. The mass of the upper eccentric block affects the intensity of the circular motion of the granular media, and the mass of the lower eccentric block affects the intensity of the tumbling motion of the granular media. Selecting a phase difference of 90°, increasing the motor rotational speed and the eccentric block’s mass can increase the granular media’s velocity and force. This study provides a reference for improving processing efficiency and changing granular media flow field motion.</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":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144108465","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":"Simplified approach for liquefaction assessment in granular soils: integrating bulk and grain properties","authors":"Mujeeb Ul Rehman,&nbsp;Ramesh Kannan Kandasami,&nbsp;Subhadeep Banerjee","doi":"10.1007/s10035-025-01529-4","DOIUrl":"10.1007/s10035-025-01529-4","url":null,"abstract":"<div><p>Particle characteristics (particle shape and size), along with relative density, significantly influence the frictional characteristics and liquefaction behavior of granular materials, particularly sand. While many studies have examined the individual effects of particle shape, gradation, and relative density on the frictional characteristics and liquefaction behavior of sand, they have often overlooked the combined effects of these soil parameters. In this study, the individual effect of these three soil parameters on the strength characteristics (angle of internal friction) and liquefaction resistance has been quantified by analyzing the data available in the literature. A novel dimensionless parameter, the ‘packing index (<span>(alpha )</span>),’ was developed to account for the bulk characteristics (relative density - RD) and grain properties (gradation, represented by the coefficient of uniformity (<span>(C_u)</span>), and particle shape represented by the shape descriptor regularity (<span>(rho )</span>)) of the granular soils. Through statistical analysis, a power law-based equation was proposed and validated to relate the cyclic resistance ratio (<i>CRR</i>) and angle of internal friction (<span>(phi )</span>) with the packing index. Finally, an approach to assess the liquefaction resistance was detailed considering the intrinsic soil parameters, aiming to bridge the gap between field observations and laboratory analysis to facilitate a comprehensive understanding of soil behavior under cyclic loading.</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":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144108464","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":"CFD-DEM investigation of suffusion-induced cyclic shear degradation in gap-graded soils: roles of mean stress and stress anisotropy","authors":"Kun Pan,&nbsp;Chao Yu,&nbsp;Zheng Hu,&nbsp;Mengfen Shen","doi":"10.1007/s10035-025-01536-5","DOIUrl":"10.1007/s10035-025-01536-5","url":null,"abstract":"<div><p>Hydraulic structures such as embankments and dams are essential for water storages, flood control, and transportation, but are vulnerable to suffusion under complex loading conditions. This study investigates the effect of suffusion on the cyclic shear behavior of gap-graded soils using the coupled computational fluid dynamics and discrete element method (CFD-DEM). A series of seepage infiltration and drained cyclic shear tests are conducted on specimens with varying mean stresses and initial stress anisotropy to systematically evaluate the mechanical consequences of suffusion. The findings reveal that the higher mean stress and initial stress anisotropy significantly exacerbate fines loss and deformation, particularly along principal seepage directions during suffusion. Furthermore, the eroded specimens exhibit substantial stiffness degradation and microstructural changes, including the deteriorated interparticle contacts and more pronounced fabric anisotropy. Notably, fines loss intensifies the load-bearing reliance on coarse particles during cyclic loading. These results provide new micromechanical insights into suffusion-induced degradation, offering valuable implications for developing advanced constitutive model of gap-graded soils accounting for suffusion-induced fines loss and cyclic loading conditions.</p></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"27 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144108463","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":"Tuning geometry in staple-like entangled particles: “pick-up” experiments and Monte Carlo simulations","authors":"Youhan Sohn,&nbsp;Saeed Pezeshki,&nbsp;Francois Barthelat","doi":"10.1007/s10035-025-01531-w","DOIUrl":"10.1007/s10035-025-01531-w","url":null,"abstract":"<div><p>Entangled matter provides intriguing perspectives in terms of deformation mechanisms, mechanical properties, assembly and disassembly. However, collective entanglement mechanisms are complex, occur over multiple length scales, and they are not fully understood to this day. In this report, we propose a simple pick-up test to measure entanglement in staple-like particles with various leg lengths, crown-leg angles, and backbone thickness. We also present a new “throw-bounce-tangle” model based on a 3D geometrical entanglement criterion between two staples, and a Monte Carlo approach to predict the probabilities of entanglement in a bundle of staples. This relatively simple model is computationally efficient, and it predicts an average density of entanglement which is consistent with the entanglement strength measured experimentally. Entanglement is very sensitive to the thickness of the backbone of the staples, even in regimes where that thickness is a small fraction (&lt; 0.04) of the other dimensions. We finally demonstrate an interesting use for this model to optimize staple-like particles for maximum entanglement. New designs of tunable “entangled granular metamaterials” can produce attractive combinations of strength, extensibility, and toughness that may soon outperform lightweight engineering materials such as solid foams and lattices.</p></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"27 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10035-025-01531-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144090962","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}