Granular Matter最新文献

A new numerical method for constructing the three-dimensional microstructure of S-RM using digital image processing technology 利用数字图像处理技术构建 S-RM 三维微观结构的新数值方法

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-01-26 DOI: 10.1007/s10035-023-01393-0

Yiliang Tu, Hang Long, Zhong Fang, Hejun Chai, Xinrong Liu, Lizhou Zhang, Wenlong Yang

{"title":"A new numerical method for constructing the three-dimensional microstructure of S-RM using digital image processing technology","authors":"Yiliang Tu, Hang Long, Zhong Fang, Hejun Chai, Xinrong Liu, Lizhou Zhang, Wenlong Yang","doi":"10.1007/s10035-023-01393-0","DOIUrl":"10.1007/s10035-023-01393-0","url":null,"abstract":"<div><p>Soil-rock mixture (S-RM) is widely distributed in some accumulation slopes and commonly used as a backfill material in the field of geotechnical engineering. The mechanical properties of S-RM play a pivotal role in ensuring the stability of geotechnical engineering projects. The discrete element method (DEM), which can construct S-RM’s microstructure model, is an effective tool for studying its mechanical properties. Currently, the most realistic and precise approach for constructing a three-dimensional (3D) microstructure model of S-RM is digital image processing (DIP) technology using computed tomography (CT) scanning device or 3D laser scanning device. However, these devices are very expensive. This study aims to develop an economical and accurate DEM for constructing the 3D microstructure of S-RM using DIP technology with a conventional digital camera. Firstly, a digital camera was used to capture three sets of 2D images on real rock blocks around four circles at different angles. DIP technology was then applied to process the 2D images and construct the refined 3D rock block grid models. Subsequently, the geometric parameters of the grid models were compared with those of the corresponding real rock blocks to validate the accuracy and applicability of this method. The microstructure model of S-RM in the large-scale direct shear test was then established and verified for DEM simulations. Finally, the mechanical properties of S-RM were analyzed based on the evolution of the shear band, the rotation of rock blocks, and the change of contact force chain.</p><h3>Graphic abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":582,"journal":{"name":"Granular Matter","volume":"26 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139578911","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

Development of performance test system for virtual impactor of respirable dust 开发可吸入粉尘虚拟冲击器性能测试系统

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-01-23 DOI: 10.1007/s10035-023-01392-1

Lifeng Hui

{"title":"Development of performance test system for virtual impactor of respirable dust","authors":"Lifeng Hui","doi":"10.1007/s10035-023-01392-1","DOIUrl":"10.1007/s10035-023-01392-1","url":null,"abstract":"<div><p>This work introduces a polydisperse aerosol testing system for respirable dust virtual impactor evaluation for the first time, and characterizes its performance. The aerosol in the dust chamber diluted and mixed completely, its diameter distribution follows a lognormal distribution. Although the aerosol concentration increased from top to bottom in the chamber, the particle distribution in the same measurement plane was relatively uniform. The sample flow rate of the test system is stable, and the change of temperature on the flow rate is negligible. The most common virtual impactor with the operating point flow rate of 4 L/min was selected as the subject, and its separation performance, flow variation and load characteristics were evaluated by this test system. The results show that the cutoff diameter deviation is − 2.8% and the maximum deviation from the BMRC curve is − 4.85%. The deviation in the cut-off diameter was more likely to be caused by the minor flow rate than that of a major flow rate. With an increase in the loading time and dust concentration, the virtual impactor was overloaded, which required maintenance according to its actual usage.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":582,"journal":{"name":"Granular Matter","volume":"26 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139523393","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

Fragmentation model integrated in a gravity flow simulator for block caving planning 集成在重力流模拟器中的破碎模型，用于块体洞穴规划

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-01-20 DOI: 10.1007/s10035-024-01396-5

Raúl Castro, René Gómez, José Castillo, Oscar Jerez

{"title":"Fragmentation model integrated in a gravity flow simulator for block caving planning","authors":"Raúl Castro, René Gómez, José Castillo, Oscar Jerez","doi":"10.1007/s10035-024-01396-5","DOIUrl":"10.1007/s10035-024-01396-5","url":null,"abstract":"<div><p>Rock fragment size is a key variable in several mining stages such as underground mine design, equipment selection, and mineral processing. In Block Caving, rock fragment sizes are affected by fragmentation during gravity flow in the ore column while ore is being extracted from drawpoints. Additionally, smaller fragments can percolate between large fragments during gravity flow. These two phenomena — rock fragmentation and particle percolation — are not easy to simulate at a large scale in Block Caving. In this paper, a fragmentation model in a cellular automata gravity flow simulator is proposed to model rock fragmentation during flow at large scales. The fragmentation model uses the rock strength, vertical stresses, and travel distance as inputs to estimate the rock breakage and was calibrated with experimental and mine data. The mine scale results show an error of 9% and 7% of the fragmentation in the zones evaluated. This error rate is considered low due to the variability of the phenomena involved. Then, integrating a fragmentation model into a gravity flow simulator can more realistically represent ore fragmentation in caving-mine to generate flow simulations.</p></div>","PeriodicalId":582,"journal":{"name":"Granular Matter","volume":"26 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139516433","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

Continuum modelling of a just-saturated inertial column collapse: capturing fluid-particle interaction 刚饱和惯性柱坍塌的连续建模：捕捉流体与颗粒的相互作用

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-01-19 DOI: 10.1007/s10035-023-01391-2

William Webb, Barbara Turnbull, Chris Johnson

{"title":"Continuum modelling of a just-saturated inertial column collapse: capturing fluid-particle interaction","authors":"William Webb, Barbara Turnbull, Chris Johnson","doi":"10.1007/s10035-023-01391-2","DOIUrl":"10.1007/s10035-023-01391-2","url":null,"abstract":"<p>This work presents a simple two-phase flow model to analyse a series of axisymmetric granular column collapse tests conducted under elevated gravitational accelerations. These columns were prepared with a just-saturated condition, where the granular pores were filled with a Newtonian fluid up to the column’s free surface. In this configuration, unlike the fully submerged case, air-water-grain contact angles may be important to flow dynamics. The interaction between a Newtonian fluid phase and a monodispersed inertial particle phase was captured by an inter-phase interaction term that considers the drag between the two phases as a function of the particle phase porosity. While this experimental setup has broad applications in understanding various industrial processes and natural phenomena, the focus of this study is on its relevance to predicting the motion of debris flows. Debris flows are challenging to model due to their temporally evolving composition, which can lead to the development of complex numerical models that become intractable. The developed numerical scheme in this study reasonably reproduces the particle-size and gravitational acceleration dependencies observed within the experimental runout and basal fluid pressure dissipation data. However, discrepancies between the model and physical experiments primarily arise from the assumption of modelling the granular phase as a continuum, which becomes less appropriate as particle size increases.</p>","PeriodicalId":582,"journal":{"name":"Granular Matter","volume":"26 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10035-023-01391-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139500905","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

Investigation techniques and physical aspects of the angle of repose of granular matter 颗粒物料倾角的研究技术和物理问题

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-01-19 DOI: 10.1007/s10035-023-01378-z

Sacha Duverger, Vasileios Angelidakis, Sadegh Nadimi, Stefano Utili, Stéphane Bonelli, Pierre Philippe, Jérôme Duriez

{"title":"Investigation techniques and physical aspects of the angle of repose of granular matter","authors":"Sacha Duverger, Vasileios Angelidakis, Sadegh Nadimi, Stefano Utili, Stéphane Bonelli, Pierre Philippe, Jérôme Duriez","doi":"10.1007/s10035-023-01378-z","DOIUrl":"10.1007/s10035-023-01378-z","url":null,"abstract":"<div><p>The repose of granular materials is investigated via two different Discrete Element Method (DEM) implementations in comparison with an experimental reference from a recently proposed benchmark setup. On a methodological standpoint, a rigorous measurement method of the angle of repose (AOR) is first proposed for plane-strain and axisymmetric conditions as encountered in the reference experiments.Additionally, two systematic procedures are designed in order to also determine the void ratio of the heap, as a fundamental property of granular matter possibly influencing the AOR. A physical discussion is then developed on the role of particle shape, considering the non-spherical nature of reference particles with a convexity value of <span>(C = 0.954)</span>. Adoping non-convex multi-spheres aggregates (i.e. clumps), the first DEM modelling approach successfully predicts the AOR within a 8% tolerance. After a convex simplification that neglects local concavities, another approach based on potential particles underestimates to a greater extent the AOR, bringing it down from <span>(35.95 pm 0.88^{circ })</span> to <span>(31.26 pm 0.95^{circ })</span>. For the loading setup(s) at hand, the AOR is eventually shown to bear no constitutive nature. It is for instance independent of initial void ratio but is still different than the critical friction angle. The latter may actually serve as a lower bound for the process-dependent AOR. These conclusions are drawn from a statistical analysis of a large set of results, accounting for the random nature of the microscopic arrangement in the studied process.</p></div>","PeriodicalId":582,"journal":{"name":"Granular Matter","volume":"26 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139500913","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

Statistical interdependence of multi-scale 3D morphological descriptors of sand grains 沙粒多尺度三维形态描述符的统计相互依存性

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-01-16 DOI: 10.1007/s10035-023-01390-3

Rizwan Khan, Gali Madhavi Latha

{"title":"Statistical interdependence of multi-scale 3D morphological descriptors of sand grains","authors":"Rizwan Khan, Gali Madhavi Latha","doi":"10.1007/s10035-023-01390-3","DOIUrl":"10.1007/s10035-023-01390-3","url":null,"abstract":"<div><p>Particle morphology at different length scales is important in understanding the mechanical behaviour of granular materials. In this sense, it is crucial to accurately describe and measure the size and shape of the grains using suitable definitions of morphological descriptors. Most of the research up until this point has analyzed particle shape in a two-dimensional framework, and sieving has typically been used to determine size. This paper describes the use of x-ray micro-computed tomography (µCT) which enables the visualization and quantification of three-dimensional particle morphology. Spherical harmonic analysis was used to reconstruct the three-dimensional (3D) realistic surface of the granular particles. 3D morphological descriptors were then introduced and computed to obtain the overall form, local features, and surface textures of the particle morphology based on the spherical harmonic reconstructed surface. To describe the fractal nature of the surfaces of natural sand particle morphology, the 3D fractal dimension was quantified using spherical harmonic-based fractal analysis. Complete volume-based distributions of particle morphological descriptors were presented and compared for four different sand samples with different grain size and shape characteristics. According to the statistical analysis, there is a clear correlation between the shape parameters at various characteristic scales, indicating that they are not independent measures. The correlation between any two parameters was observed to rely on the distance between the characteristic scales of the morphological parameters.</p><h3>Graphic abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":582,"journal":{"name":"Granular Matter","volume":"26 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139476910","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

Implications of sand grains’ mobility and inundating area to landslides at different slope angles 不同坡角下砂粒的流动性和淹没面积对滑坡的影响

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-01-13 DOI: 10.1007/s10035-023-01387-y

Yan-Bin Wu, Zhao Duan, Jian-Bing Peng, Qing Zhang

{"title":"Implications of sand grains’ mobility and inundating area to landslides at different slope angles","authors":"Yan-Bin Wu, Zhao Duan, Jian-Bing Peng, Qing Zhang","doi":"10.1007/s10035-023-01387-y","DOIUrl":"10.1007/s10035-023-01387-y","url":null,"abstract":"<div><p>The apparent friction coefficient, namely Heim’s ratio, is a prevalent dimensionless parameter to represent landslides’ mobility. Many empirical and theoretical models have been developed on the Heim’s ratio and landslides’ volume. However, studies on the ratio and their slope angles are lacking. Here, we performed a series of laboratory landslides at different slope angles to explore their mobility and motion characteristics. Our results show that the runout of the laboratory landslides decreases linearly with an increase in slope angles. A theoretical relationship between the apparent friction coefficient and slope angle is proposed, based on a hypothesis that the ratio of energy dissipation occurring when an object collides with a plane is power law to its impact angle. The relationship shows well approximation to our experimental data, and data from Crosta (IOP Conf. Ser. Earth Environ. Sci. 26:012004, 2015) and natural landslides. We also obtain that the coefficients of apparent friction and effective friction are almost identical at low slope angles. The dimensionless length and area of the laboratory landslides increase first and then decrease during their whole motion. The maximum area of them during their motion decreases with an increase in slope angles. The study will support studies on the morphological variation during the whole motion and mobility of landslides.</p></div>","PeriodicalId":582,"journal":{"name":"Granular Matter","volume":"26 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139436721","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

Effects of angularity and content of coarse particles on the mechanical behaviour of granular mixtures: a DEM study 粗颗粒的角度和含量对颗粒混合物机械性能的影响：DEM 研究

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-01-12 DOI: 10.1007/s10035-023-01386-z

Jian Gong, Xianwei Pang, Yu Tang, Zhonghan Yang, Jie Jiang, Xiaoduo Ou

引用次数: 0

Study on the anisotropy of particle fluctuation in a jet bubbling bed 喷射鼓泡床中颗粒波动的各向异性研究

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-01-09 DOI: 10.1007/s10035-023-01388-x

Xi Chen, Shuyan Wang, Baoli Shao, Lei Xie, Guangjun Kuang, Yimei Ma

{"title":"Study on the anisotropy of particle fluctuation in a jet bubbling bed","authors":"Xi Chen, Shuyan Wang, Baoli Shao, Lei Xie, Guangjun Kuang, Yimei Ma","doi":"10.1007/s10035-023-01388-x","DOIUrl":"10.1007/s10035-023-01388-x","url":null,"abstract":"<div><p>The flow behavior of particles is simulated with an Eulerian-Eulerian two-fluid model based on kinetic theory of granular flow (KTGF) in a jet bubbling bed. A second-order moment (SOM) model is applied to explore the anisotropy flow behavior of particles through kinetic interaction of particle collisions. The particle frictional stresses are calculated using equations proposed by Johnson and Jackson (J Fluid Mech 176:67–93, 1987) and Schaeffer (J Differ Eq 66:9–50, 1987). The predictions of the equivalent bubble diameter and porosity are in good agreement with experimental data by Kuipers et al. Simulated comparisons between the KTGF model and the SOM model show that the SOM model is superior to the KTGF model in capturing the inhomogeneity and anisotropy of the flow field. The simulated results demonstrate that the axial second-order moment component is significantly larger than the radial second-order moment component, and they exhibit obvious anisotropy. Finally, the impacts of jet velocity, particle diameter, and restitution coefficient on the second-order moments are analyzed, respectively. It is found that the enhancement of jet velocity and particle diameter intensifies the anisotropy of flow structure, and a higher restitution coefficient weakens the anisotropy due to the reduction of energy dissipation.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":582,"journal":{"name":"Granular Matter","volume":"26 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139414077","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

XRCT image processing for sand fabric reconstruction 用于砂织物重建的 XRCT 图像处理

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-01-08 DOI: 10.1007/s10035-023-01368-1

Peng Tan, Hasitha Sithadara Wijesuriya, Nicholas Sitar

{"title":"XRCT image processing for sand fabric reconstruction","authors":"Peng Tan, Hasitha Sithadara Wijesuriya, Nicholas Sitar","doi":"10.1007/s10035-023-01368-1","DOIUrl":"10.1007/s10035-023-01368-1","url":null,"abstract":"<div><p>We explore computationally efficient techniques to improve the XRCT image processing of low resolution and very noisy images for use in reconstruction of the fabric of densely packed, natural sand deposits. To this end we evaluate an image preprocessing workflow that incorporates image denoising, single image super resolution, image segmentation and level-set (LS) reconstruction. We show that, although computationally intensive, the Non-Local Mean (NLM) filter improves the quality of XRCT images of granular material by increasing the signal-to-noise ratio without impairing visible structures in the images, and outperforms more traditional local filters. We then explore an image super-resolution technique based on sparse signal representation and show that it performs well with noisy data and improves the subsequent stage of binarization. The image binarization is performed using a Hidden Markov Random Fields (HMRF) with Weighted Expectation Maximization (WEM) algorithm which takes the spatial information into account and performs well on high resolution images, however it still struggles with low quality images. We then use the level set method to define the grain geometry and show that the Distance Regularized LS Evolution (DRLSE) is an efficient approach for data sets with large numbers of grains. Finally, we introduce a penalty term into the evolution of the LS function, to address the issue of adhesion of much finer particles, such as clay, on the surface of the reconstructed avatars, while maintaining the main morphological details of the grains.</p></div>","PeriodicalId":582,"journal":{"name":"Granular Matter","volume":"26 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139399898","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