Granular Matter最新文献_第10页

Understanding shear bands in granular media through in-plane ploughing experiments at different strain rates 通过不同应变速率下的面内翻耕试验了解颗粒介质中的剪切带

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-12-09 DOI: 10.1007/s10035-024-01489-1

Sudhanshu Rathore, Abhijit Hegde, Tejas G. Murthy

{"title":"Understanding shear bands in granular media through in-plane ploughing experiments at different strain rates","authors":"Sudhanshu Rathore, Abhijit Hegde, Tejas G. Murthy","doi":"10.1007/s10035-024-01489-1","DOIUrl":"10.1007/s10035-024-01489-1","url":null,"abstract":"<div><p>An experimental study is made to understand the deformation characteristics and failure mechanism of sands subjected to severe plastic deformation in the ploughing model setup of in-plane orthogonal cutting. The cutting experiments were performed on sands over 3 orders of strain rates. High-speed imaging and concomitant image analysis were performed using the Particle Image Velocimetry algorithm to obtain the whole field velocity measurements of the material flow. The velocity field maps of the near tool tip region demonstrate a sharp change in the motion of sand particles along with the formation of a dead zone. The effective strain rate maps show regions of intense localized plastic deformation- termed “shear bands”. The inclination angle of these bands evolved periodically with time and showed a decreasing trend due to an increase in the surcharge and effective depth of cut. The morphology and overall characteristics of these mesoscale structures (shear bands) do not change significantly with strain rate. The cutting force signatures were oscillatory and suggested cyclic material softening (dilation)—hardening (compaction) ahead of the tool, which is also reflected in the periodic repositioning of shear bands. The limit equilibrium-based model was adequate to predict the tool-cutting forces well, even with the significant variation in strain rates.</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 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142798440","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

Using tracer particle kinematics to sense particle size in rotating drums 利用示踪粒子运动学检测旋转滚筒中的颗粒大小

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-12-06 DOI: 10.1007/s10035-024-01493-5

Sudip Laudari, Benjy Marks, Pierre Rognon

{"title":"Using tracer particle kinematics to sense particle size in rotating drums","authors":"Sudip Laudari, Benjy Marks, Pierre Rognon","doi":"10.1007/s10035-024-01493-5","DOIUrl":"10.1007/s10035-024-01493-5","url":null,"abstract":"<div><p>Comminution is an energy intensive process. In SAG-mills, it is achieved by rotating a drum in which large metal balls crush ore particles. In-situ monitoring of particle size would be of considerable interest to optimize their operation. However, there is no established solution to measure particle size in such a harsh mechanical environment. We show here that the acceleration of the grinding media, which can be monitored using embedded accelerometers, can be used to sense the particle size and size distribution during operation. In DEM simulations, we find that a machine learning classifier is able to detect the size and distribution of small particles solely based on the knowledge of the acceleration of larger grinding media particles. Results show that this kinematic sensing is effective over a wide range of particle size ratios, size distribution, mixture ratio and mill charge. Beyond their potential applications in mineral processing, these results point out that the kinematics of large particles is affected by the size of the smaller particles, an observation which can help advance rheological models for bi-disperse granular flows.</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 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10035-024-01493-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789171","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

Optimisation of soil-agent particle distribution in a new chain plate soil remediation device based on discrete element method 基于离散元法的新型链板土壤修复装置中土壤剂颗粒分布优化

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-12-04 DOI: 10.1007/s10035-024-01483-7

Zhipeng Wang, Tong Zhu, Youzhao Wang, Dezheng Liu, Feng Ma, Chaoyue Zhao, Xu Li, Yanping Zhang

{"title":"Optimisation of soil-agent particle distribution in a new chain plate soil remediation device based on discrete element method","authors":"Zhipeng Wang, Tong Zhu, Youzhao Wang, Dezheng Liu, Feng Ma, Chaoyue Zhao, Xu Li, Yanping Zhang","doi":"10.1007/s10035-024-01483-7","DOIUrl":"10.1007/s10035-024-01483-7","url":null,"abstract":"<div><p>To improve the working efficiency of in-situ soil remediation equipment, this paper designs a new type of chain plate soil remediation equipment based on the working principle and technical requirements. The mixing process of soil and chemicals under different parameters was investigated using the discrete element method and the orthogonal test method. The experimental designs were all based on horizontal movement speed, chain knife speed, screw speed, and homogeneous mixing pitch as test factors and discrete coefficient and soil fragmentation rate as indices. The test method uses a unidirectional test to determine the value of the reference centre level for the orthogonal test and a combined balancing method to determine and validate the optimum parameters of the soil remediation device. The optimised parameters were determined as follows: the horizontal movement speed of the mechanism is 0.15 m/s, the rotational speed of the chain knife is 5.25 m/s, the rotational speed of the screw is 187.5 rpm, and the homogeneous mixing pitch is 98 mm, respectively. The dispersion coefficient was reduced by 7.43% and the soil fragmentation rate increased by 5.45% compared to the operating parameters of the baseline group.</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 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142778300","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

A thermodynamic critical state model for sands 砂的热力学临界状态模型

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-12-04 DOI: 10.1007/s10035-024-01492-6

Hongjun Li, Zhichao Zhang

{"title":"A thermodynamic critical state model for sands","authors":"Hongjun Li, Zhichao Zhang","doi":"10.1007/s10035-024-01492-6","DOIUrl":"10.1007/s10035-024-01492-6","url":null,"abstract":"<div><p>A thermodynamics-based constitutive model predicting the critical state behavior of sands is developed in this paper. The model includes hyperelastic and plastic constitutive relations derived from thermodynamics. Using the concept of elastic potential, hyperelastic relations are derived to describe the stress- and -density dependency of the elastic stiffness of sands, which naturally lead to the elastic limit with stress-induced anisotropy in effective stress space. The plastic constitutive relations coupled with the nonlinear hyperelasticity are then derived based on the energy dissipations and the second law of thermodynamics. The model is capable of predicting the critical state behavior of sands without concepts of yield surface and plastic potential surface. The model is validated by predicting the undrained shear behavior of Toyoura sand. The modeling results show that different patterns of undrained shear response, such as the pure dilation type, the contraction-dilation type with hardening, the contraction-dilation type with softening, and the pure contraction type, can be well captured by the model, depending on the confining pressure and the void ratio. The distinctions of contraction/dilation and critical state behavior between triaxial compression and extension are also predicted. It is shown that the critical state behavior of sand is the combined results of the pressure/density/path-dependent hyperelasticity and plasticity coupled with each other.</p></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"27 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142778301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of powder particle size on the microscopic morphology and mechanical properties of 316 L stainless steel hollow spheres 粉末粒度对316l不锈钢空心球微观形貌和力学性能的影响

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-11-29 DOI: 10.1007/s10035-024-01495-3

Jianliang Li, Xu Cui, Qianfei Sun, Chunhuan Guo, Fengchun Jiang, Hexin Zhang

{"title":"Effect of powder particle size on the microscopic morphology and mechanical properties of 316 L stainless steel hollow spheres","authors":"Jianliang Li, Xu Cui, Qianfei Sun, Chunhuan Guo, Fengchun Jiang, Hexin Zhang","doi":"10.1007/s10035-024-01495-3","DOIUrl":"10.1007/s10035-024-01495-3","url":null,"abstract":"<div><p>316 L stainless steel powder with varying particle sizes was chosen as the raw material for the fabrication of metal hollow spheres using powder metallurgy techniques. The powder’s particle size, composition, and micro-morphology were examined, followed by porosity and capillary force calculations, compressive testing, and fracture analysis. The findings reveal significant disparities in the micro-morphology and mechanical properties among the metal powders with different particle sizes. Smaller particle sizes result in denser bonding of the hollow spheres, leading to higher compressive yield strength. Conversely, larger powder particle sizes substantially increase the porosity of the hollow sphere wall, resulting in a sharp decline in mechanical properties and a transition from ductile fracture to brittle fracture in its failure mode. This study’s innovation lies in its meticulous examination of the relationship between particle size distribution and the resulting microstructural and mechanical properties of 316 L stainless steel hollow spheres, providing valuable data that enhances the understanding of powder metallurgy processes and drives the development of advanced materials for aerospace applications.</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 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142754024","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

On response of laterally loaded granules within retaining structure 关于挡土结构内横向加载颗粒的反应

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-11-28 DOI: 10.1007/s10035-024-01484-6

Wentao Hu, Shenghong Zhang, Jin Xiao, Yuyuan Zhu

引用次数: 0

Effects of aggregate crushing and strain rate on fracture in compressive concrete with a DEM-based breakage model 利用基于 DEM 的断裂模型分析骨料破碎和应变率对抗压混凝土断裂的影响

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-11-26 DOI: 10.1007/s10035-024-01487-3

Michal Nitka, Jacek Tejchman

{"title":"Effects of aggregate crushing and strain rate on fracture in compressive concrete with a DEM-based breakage model","authors":"Michal Nitka, Jacek Tejchman","doi":"10.1007/s10035-024-01487-3","DOIUrl":"10.1007/s10035-024-01487-3","url":null,"abstract":"<div><p>This study looked at how breakable aggregates affected the mesoscopic dynamic behavior of concrete in the uniaxial compression condition. In-depth dynamic two-dimensional (2D) studies were conducted to examine the impact of aggregate crushing and strain rate on concrete’s dynamic strength and fracture patterns. Using a DEM-based breakage model, concrete was simulated as a four-phase material consisting of aggregate, mortar, ITZs, and macropores. The concrete mesostructure was obtained from laboratory micro-CT tests. Collections of spherical particles were used to imitate aggregate breakage of different sizes and shapes by enabling intra-granular fracturing between them. The mortar was described in terms of unbreakable spheres with different diameters. Compared to the mortar, the aggregate strength was always stronger. A qualitative consistency was achieved between the DEM results and the available experimental data. Concrete’s dynamic compressive strength rose significantly with strain rate and just somewhat with aggregate strength. The fracture process was impacted considerably by aggregate crushing and strain rate. The number of broken contacts grew with an increase in strain rate and a decrease in aggregate strength.</p></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"27 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10035-024-01487-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142714528","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

Reducing segregation in vibrated binary-sized granular mixtures by excessive small particle introduction 通过过度引入小颗粒减少振动双元粒状混合物中的偏析现象

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-11-20 DOI: 10.1007/s10035-024-01476-6

Fumiaki Nakai, Kiwamu Yoshii

{"title":"Reducing segregation in vibrated binary-sized granular mixtures by excessive small particle introduction","authors":"Fumiaki Nakai, Kiwamu Yoshii","doi":"10.1007/s10035-024-01476-6","DOIUrl":"10.1007/s10035-024-01476-6","url":null,"abstract":"<div><p>We numerically examine binary-sized granular mixtures confined between two parallel walls subjected to vertical vibration using the discrete element method. For a size ratio of 3 between large and small particles, we study the structure of large particles in moderately dense regimes where the combined two-dimensional packing fractions of both particle sizes exceed 1. When the fraction of small particles is small, segregation of the large particles occurs. In contrast, as the fraction of small particles increases, an effective repulsion between the large particles emerges over distances greater than the large particle diameter, suppressing their segregation. The emergence of reduction in segregation is confirmed for another size ratio, vibrational acceleration, system size, and for a case of bidisperse size distribution. Additionally, at the size ratio of 3, the effective repulsion induces a hexagonal phase of the large particles at packing fractions lower than in mono-component systems. This work will provide a fresh insight into granular physics, prompting further experimental and theoretical study.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div><div><p>This article numerically investigates the structures of quasi-two-dimensional binary-sized granular mixtures under vibration, and finds that segregation is reduced with increasing packing fraction of small particles</p></div></div></figure></div></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"27 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10035-024-01476-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679562","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

Thermal conductivity and shrinkage characteristics of bentonite-fly ash and bentonite-sand backfill material 膨润土-粉煤灰和膨润土-砂回填材料的导热性和收缩特性

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-11-19 DOI: 10.1007/s10035-024-01482-8

Pawan Kishor Sah, Shiv Shankar Kumar

{"title":"Thermal conductivity and shrinkage characteristics of bentonite-fly ash and bentonite-sand backfill material","authors":"Pawan Kishor Sah, Shiv Shankar Kumar","doi":"10.1007/s10035-024-01482-8","DOIUrl":"10.1007/s10035-024-01482-8","url":null,"abstract":"<div><p>Thermal backfill is an integrated part of underground electrical cable infrastructures systems, ground heat source pumps and radioactive waste repositories, as it minimizes resistance to heat transfer away from these systems. The heat transfer capacity and current carrying capability of underground electrical cables are significantly affected by thermal conductivity of backfill material and the surrounding soil media. Therefore, this research paper compares the thermal conductivity and shrinkage results of compacted (low to high densities) fly ash- and sand-bentonite mixtures with bentonite contents of 30%, 50%, 60%, 80% and 100%. The thermal conductivity of mixtures increased from 1.05 Wm<sup>−1</sup>K<sup>−1</sup> to 1.20 Wm<sup>−1</sup>K<sup>−1</sup> with the addition of fly ash content from 20 to 70% by weight in bentonite. The thermal conductivity bentonite-sand mixture was also found to be increased from 1.21 Wm<sup>−1</sup>K<sup>−1</sup> to 1.83 Wm<sup>−1</sup>K<sup>−1</sup> with increasing sand content. Additional to this, the bentonite-sand and bentonite-fly ash-based backfill materials surrounding heat-sensitive structures experience shrinkage and desiccation cracking due to thermal drying. Therefore, the desiccation volumetric shrinkage tests of bentonite-sand and bentonite-fly ash mixtures were conducted and found that the presence of sand or fly ash reduces shrinkage strain. Based on the experimental results, this study suggests a sustainable utilization of fly ash up to 50%-70% as an effective thermal backfill material in electrical cable infrastructure systems. Thus, the application of fly ash as a construction material reduces environmental impact and cost, aligning with the goals of sustainable development.</p></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"27 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672436","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

Experimental studies on fluctuation properties of dust, turbulence and electric field during floating dust weather in Lanzhou 兰州浮尘天气中尘埃、湍流和电场波动特性的试验研究

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-11-15 DOI: 10.1007/s10035-024-01481-9

Tian-sheng Liu, Tian-Li Bo

{"title":"Experimental studies on fluctuation properties of dust, turbulence and electric field during floating dust weather in Lanzhou","authors":"Tian-sheng Liu, Tian-Li Bo","doi":"10.1007/s10035-024-01481-9","DOIUrl":"10.1007/s10035-024-01481-9","url":null,"abstract":"<div><p>In this paper, real-time measurements of three-dimensional wind speed, electric field and dust concentration during the floating-dust event were carried out in Lanzhou. The scaling relationship of different physical quantities in spectral space and the effect of turbulent events on dust and heat transport are studied by spectral method and octant analysis method. Our results show that the logarithmic value of power spectrum of dust concentration, relative humidity (<i>RH</i>), streamwise and vertical wind speed (<i>u</i> and <i>w</i>) between 0.06 Hz and 0.435 Hz meets the linear relationship with the logarithmic value of frequency (<i>f</i>), and decreases with the logarithmic value of <i>f</i>. For different stages, in the frequency range from 0.06 Hz to 0.218 Hz, the slope of the <i>u</i> first increases and then decreases. The slope of dust concentration and <i>RH</i> did not change significantly in the development stage, but decreased in the decay stage. The slope of the temperature (<i>T</i>) first decreases and then increases. In the frequency range from 0.218 Hz to 0.435 Hz, the slope of <i>u</i> and <i>RH</i> first increase and then decrease. The slope of the dust concentration does not change significantly during the development stage and decreases in the decay stage. The slope of <i>w</i> first increases and then decreases. In the second stage, the contribution of ejection and sweep events to the turbulent motion increases. For dust and heat transport, the O<sub>5</sub> and O<sub>8</sub> have a larger number contribution. Although the number and intensity contribution ratio of all octants increased or decreased in the second and third stages, in terms of the intensity of a single event, the contribution of all octants to the dust and heat transport increased.</p></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"27 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142645769","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