Granular Matter最新文献_第10页

Numerical investigation of crack propagation regimes in snow fracture experiments 雪地断裂实验中裂纹扩展机制的数值研究

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-04-22 DOI: 10.1007/s10035-024-01423-5

Grégoire Bobillier, Bastian Bergfeld, Jürg Dual, Johan Gaume, Alec van Herwijnen, Jürg Schweizer

{"title":"Numerical investigation of crack propagation regimes in snow fracture experiments","authors":"Grégoire Bobillier, Bastian Bergfeld, Jürg Dual, Johan Gaume, Alec van Herwijnen, Jürg Schweizer","doi":"10.1007/s10035-024-01423-5","DOIUrl":"10.1007/s10035-024-01423-5","url":null,"abstract":"<div><p>A snow slab avalanche releases after failure initiation and crack propagation in a highly porous weak snow layer buried below a cohesive slab. While our knowledge of crack propagation during avalanche formation has greatly improved over the last decades, it still remains unclear how snow mechanical properties affect the dynamics of crack propagation. This is partly due to a lack of non-invasive measurement methods to investigate the micro-mechanical aspects of the process. Using a DEM model, we therefore analyzed the influence of snow cover properties on the dynamics of crack propagation in weak snowpack layers. By focusing on the steady-state crack speed, our results showed two distinct fracture process regimes that depend on slope angle, leading to very different crack propagation speeds. For long experiments on level terrain, weak layer fracture is mainly driven by compressive stresses. Steady-state crack speed mainly depends on slab and weak layer elastic moduli as well as weak layer strength. We suggest a semi-empirical model to predict crack speed, which can be up to 0.6 times the slab shear wave speed. For long experiments on steep slopes, a supershear regime appeared, where the crack propagation speed reached approximately 1.6 times the slab shear wave speed. A detailed micro-mechanical analysis of stresses revealed a fracture principally driven by shear. Overall, our findings provide new insight into the micro-mechanics of dynamic crack propagation in snow, and how these are linked to snow cover properties.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"26 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10035-024-01423-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140636945","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

Cyclic-loading effects in sand: a micromechanical study considering particle breakage 砂中的循环加载效应：考虑颗粒破碎的微机械研究

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-04-19 DOI: 10.1007/s10035-024-01421-7

Jacinto Ulloa, Ziran Zhou, John Harmon, José E. Andrade

{"title":"Cyclic-loading effects in sand: a micromechanical study considering particle breakage","authors":"Jacinto Ulloa, Ziran Zhou, John Harmon, José E. Andrade","doi":"10.1007/s10035-024-01421-7","DOIUrl":"10.1007/s10035-024-01421-7","url":null,"abstract":"<div><p>This paper investigates the response of Ottawa sand to cyclic loading using virtual oedometer tests and the level-set discrete element method. We study both the macroscopic and the micromechanical behavior, shedding light on the grain-scale processes behind the cyclic response observed in crushable sand, namely stress relaxation under strain control and ratcheting under stress control. Tests without particle breakage first show that asymmetrical frictional sliding during loading-unloading induces these cyclic-loading effects. Then, tests considering particle breakage reveal more pronounced stress relaxation and ratcheting, which decrease in rate over cycles, accompanied by increased frictional sliding and reduced particle contact forces. It is found that the broken fragments unload the most and promote an enhanced cushioning effect. These micromechanical processes contribute to a decrease in breakage potential as the cycles progress, implying that cyclically loaded materials may become more resistant to breakage when compared to the same material loaded monotonically at the same strain level. These new insights highlight the main contributions of the present work, factoring in real particle shapes from 3D X-ray tomography and notably contributing to the existing literature on the topic, where most studies rely on idealized particle shapes and rarely consider crushable grains.</p></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"26 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140630468","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

3D DEM investigation on percolation of lubricant particles during uniaxial metal powder compaction 单轴金属粉末压制过程中润滑剂颗粒渗流的三维 DEM 研究

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-04-18 DOI: 10.1007/s10035-024-01430-6

Wei Zhang, Weijian Xiao, Chuanniu Yuan, Xu Gong, Bozhan Hai, Rongxin Chen, Kun Liu

引用次数: 0

DEM model acquisition of the corn ear with bonded particle model and its simulated parameters calibration 利用粘结颗粒模型获取玉米果穗的 DEM 模型及其模拟参数校准

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-04-12 DOI: 10.1007/s10035-024-01427-1

Dandan Han, Yang Zhou, Junshan Nie, Qiqiang Li, Lin Chen, Qi Chen, Lihua Zhang

{"title":"DEM model acquisition of the corn ear with bonded particle model and its simulated parameters calibration","authors":"Dandan Han, Yang Zhou, Junshan Nie, Qiqiang Li, Lin Chen, Qi Chen, Lihua Zhang","doi":"10.1007/s10035-024-01427-1","DOIUrl":"10.1007/s10035-024-01427-1","url":null,"abstract":"<div><p>The corn variety “Zhenghong 507”, which is widely cultivated in hilly and mountainous areas of Southwest China, was assigned as the research object. The discrete element model of the mid-section of the corn ear that can be threshed was established by integrating the Hertz-Mindlin with the bonding V2 contact model, and the crucial bonding parameters were simulated and calibrated. With the measured normal threshing force (6.34 N) and tangential threshing force (4.75 N) of a single kernel as target values, the parameters of bonding characteristics between the kernel and the cob of corn ear were screened and optimized for significance via the Placket-Burman test, steepest ascent test, and the central composite design. The results indicate that the optimal parameter combinations for the normal stiffness and shear stiffness per unit area, normal strength, shear strength, contact radius between kernels, contact radius between cobs, and bonded disk scale were 3.4 × 10<sup>8</sup> N·m<sup>−3</sup>, 2.238 × 10<sup>8</sup> N·m<sup>−3</sup>, 0.6 × 10<sup>6</sup> Pa, 0.364 × 10<sup>6</sup> Pa, 1.87 mm, 16.5 mm and 1.321. Finally, the accuracy of the corn ear DEM model was validated by comparing the simulation to the physical test using the threshing rate as an evaluation index combined with the quality distribution of kernels after threshing.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div><div><p>Calibration and validation of a corn ear bonded model.</p></div></div></figure></div></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"26 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140599681","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

Particle breakage of ultra-high dam rockfills under drained shearing 排水剪切作用下超高坝填石的颗粒破碎

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-04-12 DOI: 10.1007/s10035-024-01428-0

Wei Jin, Xing Yang, Feng-chun Yang, Jin-quan Shi

引用次数: 0

Correction of the spring-dashpot-slider model 修正弹簧-斜盘-滑块模型

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-04-10 DOI: 10.1007/s10035-024-01424-4

Florian Führer, Lothar Brendel, Dietrich E. Wolf

引用次数: 0

Influences of particle size ratio and fines content on the suffusion characteristics of gap-graded soils 粒径比和细粒含量对间隙分级土壤窒息特性的影响

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-04-04 DOI: 10.1007/s10035-024-01425-3

Yi Zhao, Zheng Hu, Yewei Zheng, Qixin Wu

{"title":"Influences of particle size ratio and fines content on the suffusion characteristics of gap-graded soils","authors":"Yi Zhao, Zheng Hu, Yewei Zheng, Qixin Wu","doi":"10.1007/s10035-024-01425-3","DOIUrl":"10.1007/s10035-024-01425-3","url":null,"abstract":"<div><p>Suffusion severely threatens the stability of granular soils supporting infrastructure. While the geometric conditions of the granular soils are intrinsic to their mechanical behavior, their influences on the suffusion characteristics have not been fully understood. This study presents a micro-macro investigation of the suffusion characteristics of gap-graded soils with different fines contents and particle size ratios using the coupled computational fluid dynamics and discrete element method (CFD-DEM). The severity of the suffusion was quantified by both the loss of fines by mass and the volumetric deformation of the specimen. Meanwhile, Voronoi tessellation and weighted Delaunay method were employed to analyze the evolution of pore structures. The evolution of different contact types was used to analyze the rearrangement of the specimen skeleton. The simulation results show that suffusion is aggravated under otherwise identical conditions with an increase in particle size ratio and fines content. The particle size ratio influences the local pore difference between coarse and fine particles, while the fines content influences the fines’ contribution to the soil skeleton. The evolution of the distribution of local void fractions, constriction size distributions, stress-reduction factors, different types of coordination numbers, and different types of contact forces provides useful insights into the microscopic mechanism of the suffusion process.</p></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"26 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140599666","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 evaluation of the effect of size and strain rate on particle strength of rockfill materials 粒度和应变率对填石材料颗粒强度影响的统计评估

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-04-01 DOI: 10.1007/s10035-024-01417-3

Shihao Yan, Shichun Chi, Yu Guo, Jinwei Wang, Xinjie Zhou

{"title":"Statistical evaluation of the effect of size and strain rate on particle strength of rockfill materials","authors":"Shihao Yan, Shichun Chi, Yu Guo, Jinwei Wang, Xinjie Zhou","doi":"10.1007/s10035-024-01417-3","DOIUrl":"10.1007/s10035-024-01417-3","url":null,"abstract":"<div><p>The deformation of rockfill materials is mostly caused by particle breakage and subsequent skeleton adjustment. To investigate the effect of size and strain rate on particle strength under seismic load, a series of single particle crushing tests with different sizes and loading rates were conducted. The results show that the particle strength increases with the loading rate, while the size effect on particle strength gradually weakens. Furthermore, within the framework of the weakest chain theory, the failure probability per unit volume and the spatial location distribution of microcracks are discussed, and a statistical model for quasi-static particle strength is established. The spatial location of microcracks follows a power law distribution, and there is a specific power exponent at different strain rates, so that the compound parameters of the particle volume and failure probability are gathered on a master curve determined by the weakest chain statistics. The strain rate effect reduces the failure probability per unit volume and makes the spatial location distribution of microcracks sparser.</p></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"26 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140353083","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

Scale-up of dry impregnation processes for porous spherical catalyst particles in a rotating drum: experiments and simulations 旋转滚筒中多孔球形催化剂颗粒干法浸渍工艺的放大：实验与模拟

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-03-30 DOI: 10.1007/s10035-024-01416-4

Pengfei Xu, Yangyang Shen, Bryant Avila, Hernán A. Makse, Maria S. Tomassone

{"title":"Scale-up of dry impregnation processes for porous spherical catalyst particles in a rotating drum: experiments and simulations","authors":"Pengfei Xu, Yangyang Shen, Bryant Avila, Hernán A. Makse, Maria S. Tomassone","doi":"10.1007/s10035-024-01416-4","DOIUrl":"10.1007/s10035-024-01416-4","url":null,"abstract":"<p>Catalyst impregnation is the first step and one of the most crucial steps for preparing industrial catalysts. The process is typically performed in rotating vessels with a spray-nozzle to distribute the liquid onto porous catalyst supports until the pore volume is reached. The inter-particle variability of the impregnated liquid inside the particles significantly affects the activity and selectivity of the resulting catalyst. Current scale-up practices lead to poor fluid distribution and inhomogeneity in the liquid content. The aim of this work is to understand the dynamic behavior of the particles under the spray nozzle, which is essential for desired content uniformity, and to develop a scale-up model for the dry impregnation process. In this work, we considered four dimensionless numbers in the scaling analysis. The scale-up rules require that the dimensionless numbers are kept constant for different scales. Both DEM simulations and matching experiments of dry impregnation inside the porous particles were performed for different vessel sizes. The water content of the particles was compared for different times and locations, and the relative standard deviation is calculated from the axial water content. Simulation and experimental results show that particles achieve similar content uniformity at the end of impregnation, confirming that the scale-up rules are applicable to all vessel sizes. The dimensionless numbers give very good scale-up performance since curves collapse indicating similarity in the processes. In addition, the scale-up method is validated for different particle sizes in simulations.</p>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"26 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10035-024-01416-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140599756","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 on the spreading behaviour of sand powder used in binder jet 3D printing 关于粘合剂喷射三维打印中使用的砂粉扩散行为的研究

IF 2.4 3区工程技术

Granular Matter Pub Date : 2024-03-29 DOI: 10.1007/s10035-024-01420-8

Yulun Xu, Lanzhou Ge, Wenguang Nan

{"title":"Investigation on the spreading behaviour of sand powder used in binder jet 3D printing","authors":"Yulun Xu, Lanzhou Ge, Wenguang Nan","doi":"10.1007/s10035-024-01420-8","DOIUrl":"10.1007/s10035-024-01420-8","url":null,"abstract":"<div><p>The spreading behaviour of cohesive sand powder is modelled by Discrete Element Method, and the spreadability and the mechanical jamming are focused. The empty patches and total particle volume of the spread layer are examined, followed by the analysis of the geometry force and jamming structure. The results show that several empty patches with different size and shapes could be observed within the spread layer along the spreading direction even when the gap height increases to 3.0<i>D</i><sub>90</sub>. Large particles are more difficult to be spread onto the base due to jamming, although their size is smaller than the gap height. Size segregation of particles occurs before particles entering the gap between the blade and base. There are almost no particles on the smooth base when the gap height is small, due to the full-slip flow of particles. The difference of the spread layer and spreadability between the cases with rough and smooth base is reduced by the increase of the gap height. An interesting correlation between jamming effect and local defects (empty spaces) in the powder layer is identified. The resistance to particle rolling is important for the mechanical jamming reported in this work. The jammed particles with a larger size ratio tend to be more stable.</p></div>","PeriodicalId":49323,"journal":{"name":"Granular Matter","volume":"26 2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140325328","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