Computational Particle Mechanics最新文献

{"title":"Comparison of different methodologies for estimating local density in particle-based simulations","authors":"Elias Ganthaler,&nbsp;Sameen Mustafa,&nbsp;Angelika Peer","doi":"10.1007/s40571-024-00870-4","DOIUrl":"10.1007/s40571-024-00870-4","url":null,"abstract":"<div><p>Knowledge about the local relative density and porosity over a randomly packed particle system is important as it provides valuable insights into the system’s behaviour, as several numerical simulations rely on this information. In this study, different methods of estimating the local density of particle systems are compared and contrasted. These methods depend on particle-based data and can be applied to a wide variety of particle systems, including granular materials and powders. The first method divides the volume of interest along an axis; the second along two and three axes; the third is based on the probability density function of kernel densities (KDE); the fourth uses the Caley–Menger method; the fifth uses the method presented by Strobel; and the sixth performs a Delaunay triangulation of the volume, where two different implementations are investigated. In this study, discrete element method (DEM) simulations are performed to produce the dataset used for comparison. Randomly packed particles with varying radii within a predefined region of interest (ROI) are considered for simulations. The aforementioned methods are then employed to estimate the local relative density at any point in the ROI. The results indicate that the method based on the Voronoi tessellation provides the most accurate local density estimation.</p></div>","PeriodicalId":524,"journal":{"name":"Computational Particle Mechanics","volume":"12 2","pages":"1217 - 1231"},"PeriodicalIF":2.8,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919009","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":"Modeling Gas–Solid Flows in Circulating Fluidized Bed Risers Using Computational Fluid Dynamics","authors":"Diego Nei Venturi,&nbsp;Carlos Antonio Ribeiro Duarte,&nbsp;Francisco José de Souza","doi":"10.1007/s40571-024-00875-z","DOIUrl":"10.1007/s40571-024-00875-z","url":null,"abstract":"<div><p>The present work focuses on the advanced modeling and simulation of gas–solid flows in circulating fluidized bed (CFB) risers using computational fluid dynamics (CFD). Gas–solid flows play a crucial role in various industrial processes, particularly in the recovery of heavy petroleum fractions. The research utilizes the Euler–Lagrange framework with a point-particle approach to model these flows. For dense flow conditions, the gas phase formulation is modified to account for volume fraction. Additionally, a stochastic particle–particle collision model, which is computationally less intensive than deterministic approaches and previously untested for dense flows, is employed. Key findings indicate that the dilute flow formulation remains valid up to a solid mass loading 8 in well-distributed vertical flows. However, in CFB risers, due to the agglomeration of solids into clusters, the dense formulation becomes necessary at lower mass loadings of 4. Comparisons with experiments and simulations using deterministic models demonstrate that the proposed stochastic model accurately predicts dense gas–solid flows in CFB risers up to 22. Finally, the implications of this study are significant for industrial applications, providing a computationally efficient method to accurately model dense gas–solid flows, which is essential for optimizing processes in the petroleum industry.</p></div>","PeriodicalId":524,"journal":{"name":"Computational Particle Mechanics","volume":"12 2","pages":"1263 - 1290"},"PeriodicalIF":2.8,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919007","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 analysis of subway construction and groundwater seepage in spring area using PD-FVM coupling method","authors":"Zongqing Zhou,&nbsp;Daosheng Zhang,&nbsp;Chenglu Gao,&nbsp;Zhuohui Li,&nbsp;Xu Guo,&nbsp;Chengshun Shang,&nbsp;Penghui Wang","doi":"10.1007/s40571-024-00874-0","DOIUrl":"10.1007/s40571-024-00874-0","url":null,"abstract":"<div><p>The impact of subway tunnel construction on the surrounding strata and hydrogeological environment presents a multifaceted challenge. Jinan is characterized by numerous springs and rich karst groundwater resources, contributing to an exceptionally intricate urban groundwater system. This study establishes an efficient computational framework combining peridynamics (PD) and the finite volume method (FVM) to simulate the excavation of engineering-scale subway tunnels under fluid–solid coupling conditions. The modeling and analysis process of the PD-FVM coupling method is demonstrated using the Jinan Metro as a case study. Considering factors such as groundwater levels, tunnel buried depths, and geological conditions (presence of fractures), 20 sets of numerical simulation cases are designed. Engineering-scale simulations of groundwater seepage and the evolution of surrounding rock damage and deformation during subway construction in the spring area are conducted. The study culminates in an analysis of the interaction between subway construction and groundwater seepage, providing essential theoretical support for rail transit route design and the safety of tunnel engineering projects.</p></div>","PeriodicalId":524,"journal":{"name":"Computational Particle Mechanics","volume":"12 3","pages":"1529 - 1547"},"PeriodicalIF":2.8,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145161397","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":"Numerical simulation of the meso-mechanical properties of double cruciform fissures rocks after freeze–thaw cycles","authors":"Jinpeng Cao,&nbsp;Jun Hu,&nbsp;Xinrong Wang,&nbsp;YuJiang Yang,&nbsp;Zhiguo Xia,&nbsp;Hukun Wang,&nbsp;Bin Yang","doi":"10.1007/s40571-024-00877-x","DOIUrl":"10.1007/s40571-024-00877-x","url":null,"abstract":"<div><p>Investigating the mechanical properties and microscopic damage behavior of fissured rock masses subjected to freeze–thaw (F-T) cycles is essential for informing stability evaluation and disaster prevention strategies in geotechnical engineering within cold regions. In this study, a numerical simulation model of rock mass specimens with double cruciform fissures was developed applied PFC^2D, and uniaxial compression strength (UCS) tests were performed until the F-T cycles of 10, 20, 30, and 40 values for strength variation and damage characteristics assessed. The results indicate a distinct trend in damage evolution: Tensile cracks predominate during the early F-T cycles, while the proportion of shear cracks increases significantly with the number of cycles, rising from 5.89% at 0 cycles to 17.95% subjected to 40 cycles. A comparison of the cracks evolution in rock specimens between 0 and 40 F-T cycles at various inclinations revealed that the damage initially occurs at the tips of prefabricated fissures. After 40 F-T cycles, damage at these tips intensified markedly, accompanied by numerous surface cracks on rock specimens experiencing freeze–thaw deterioration. UCS tests on the models demonstrated that when only one fissure is altered, peak stress exhibits an N-shaped variation relative to changes in the fissure angle, with relatively small variances (4.77 for peak stress variance and 0.04 for modulus variance). In contrast, when both fissures are adjusted simultaneously, variances increase sharply to 12.9 and 0.16, respectively; maximum strength occurs at angles of 30° and 75°, while minimum values are observed at angles of 15° and 60°. Finally, force chains and stress distribution within the rock samples were predominantly concentrated around the fissures and shifted responsively according to alterations in loading stress and fissure angle; following damage occurrence, a low-stress zone developed near the fissures which expanded as the angle increased.</p></div>","PeriodicalId":524,"journal":{"name":"Computational Particle Mechanics","volume":"12 3","pages":"1549 - 1564"},"PeriodicalIF":2.8,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145160971","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":"Numerical investigation on the mechanical and stress characteristics of rock containing a spherical defect under uniaxial compression","authors":"Can Cui,&nbsp;Qianchen Wang,&nbsp;Wenqiang Ma","doi":"10.1007/s40571-024-00866-0","DOIUrl":"10.1007/s40571-024-00866-0","url":null,"abstract":"<div><p>Spherical defects widely exist in natural rock and severely affect the stability of rock material. Laboratory tests and numerical simulations are performed to reveal the influence of the size and the location of spherical defects on the mechanical properties, stress distribution, and fracture modes of specimens. The experimental results show that the uniaxial compressive strength (UCS) and elastic modulus of the specimen decrease with the increase in defective size. Compared with the complete specimen, the UCS and elastic modulus of specimen D5 are reduced by 48% and 53%, respectively. For specimens with different locations of spherical defect, the closer the defect is to the boundary of the specimen, the lower the UCS of the specimen. The result is P5 &lt; P6 &lt; P9 &lt; P3 &lt; P8 &lt; P7 &lt; P2 &lt; P4 &lt; P1. However, the location of the defect has minimal impact on the elastic modulus of the specimen. The stress distribution around the spherical defect was monitored by measuring balls. Numerical stress distribution results around the defect suggest that stress values near the defect are positively proportional to the defective size, while the stress values close to the model boundary are negatively proportional to the defective size. Simulation results of crack evolution reveal that the larger the defect is or the closer the defect is to the boundary, the earlier the arrival of crack initiation and propagation is. The failure characteristics and macroscopic fracture distribution from the numerical simulation agree with the experimental results. The research findings could supply a certain reference for stability analysis and control of rock material containing similar types of defects.</p></div>","PeriodicalId":524,"journal":{"name":"Computational Particle Mechanics","volume":"12 3","pages":"1507 - 1527"},"PeriodicalIF":2.8,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145171579","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":"An intelligent optimization method for stabilizing parameters in the maintenance of ballast particles","authors":"Shunwei Shi,&nbsp;Bowen Hou,&nbsp;Yixiong Xiao,&nbsp;Zhihan Zhang,&nbsp;Chunyu Wang,&nbsp;Liang Gao","doi":"10.1007/s40571-024-00871-3","DOIUrl":"10.1007/s40571-024-00871-3","url":null,"abstract":"<div><p>Stabilizing operations are crucial for improving the mechanical states of ballast particles during railway maintenance. An intelligent optimization method for stabilizing parameters is proposed in this study. First, a ballasted track-stabilizing unit coupling model is constructed using DEM-MFBD, which is an effective method for the coupling simulation of discrete and continuous bodies. Subsequently, a surrogate model of stabilizing parameters-objective functions is established using RBF, which has high robustness and accuracy for little sample. Finally, the optimal stabilizing parameters are determined using MOGA, which has a good global search capability. The results indicate that the contact force, compactness, coordination number of the ballast, and the pressure on sleeper are the most sensitive to stabilizing parameters, and 32.59 Hz and 240 kN are recommended as the optimal stabilizing frequency and vertical force, respectively. The proposed intelligent optimization method involves the interaction of stabilizing parameters, and it offers higher accuracy and efficiency than traditional optimization methods. This study provides theoretical guidance for improving railway maintenance.</p></div>","PeriodicalId":524,"journal":{"name":"Computational Particle Mechanics","volume":"12 2","pages":"1233 - 1248"},"PeriodicalIF":2.8,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919072","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 on the compressive deformation and re-bearing capacity characteristics of broken rock mass in deep roadway","authors":"Diyuan Li,&nbsp;Hao Gong,&nbsp;Pingkuang Luo,&nbsp;Wenkai Ru","doi":"10.1007/s40571-024-00868-y","DOIUrl":"10.1007/s40571-024-00868-y","url":null,"abstract":"<div><p>Under the deep high ground stress conditions, the large deformation roadway is mainly due to the enhanced expansion deformation and shear deformation of the surrounding rock, which leads to an elevated fragmentation degree of surrounding rock. At this time, the support object of the anchor is transformed from the fissured rock mass to the broken rock mass (BRM). Under the action of the anchoring force, BRM and anchor carry the secondary stress after the excavation of the roadway. In this paper, constrained compression tests of BRM at different grain sizes are carried out using indoor tests and numerical simulations. The test results show that the compressive deformation curve of the BRM includes three stages of slip flow deformation, fracture-filling deformation and compacted elastic deformation. As the grain size of the BRM increases, the maximum axial deformation and the sustained compressive time gradually increase, and the porosity and compactness inside specimen gradually decrease. As the freedom degree of the BRM increases, leading to the gradual increase in the number of acoustic emission events and cumulative energy at different stages, the weight proportion of rock mass at each stage of the grain size after compression screening gradually decreases. Based on a set of multi-view 2D images of BRM, the morphological features of the BRM are quickly reconstructed. The cluster model of the BRM is established in PFC^3D software by using the fragment replacement method (FRM) to realize the whole process simulation of the BRM. It is found that the BRM is dominated by tensile failure during the compressive process. As the grain size of the BRM increases, the contact force of the skeleton force chain gradually increases and the number gradually decreases, and the internal structural stability of specimen is weakened. The porosity loss and the coordination number inside specimen gradually increased, and the secondary fragmentation phenomenon is obvious. Therefore, in the deep roadway drilling and blasting excavation process should try to ensure the presence of large-scale BRM in the surrounding rock.</p></div>","PeriodicalId":524,"journal":{"name":"Computational Particle Mechanics","volume":"12 2","pages":"1181 - 1196"},"PeriodicalIF":2.8,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919017","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":"Nitsche-based material point method for large deformation frictional contact problems","authors":"Kun Zhang,&nbsp;Shui-Long Shen,&nbsp;Hui Wu,&nbsp;Annan Zhou","doi":"10.1007/s40571-024-00846-4","DOIUrl":"10.1007/s40571-024-00846-4","url":null,"abstract":"<div><p>Large deformation problems in practical engineering are often accompanied by contact phenomena. While the conventional material point method (MPM) is efficient at solving large deformation problems, it cannot handle slip contacts. This paper presents Nitsche’s method for analysing large deformations with frictional contact via the MPM. Nitsche’s method has good features of variational consistency and no additional unknowns, and it is integrated into the MPM in a weak manner based on the principle of virtual power. Within the integrated formulation, both biased and unbiased computational schemes are derived to adapt to different forms of contact. Additionally, B-spline shape functions are employed to alleviate cell-crossing noise, and an improved particle extrapolation approach for accurate contact detection is introduced. The efficacy of the proposed Nitsche-based MPM is validated through several representative benchmarks from the literature. We further apply the proposed method to simulate the water leakage problem of the lining gasketed joint in shield tunnels. Comparison with experimental results demonstrates the applicability of the proposed method.</p></div>","PeriodicalId":524,"journal":{"name":"Computational Particle Mechanics","volume":"12 2","pages":"947 - 970"},"PeriodicalIF":2.8,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919065","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":"Chaotic advection of fluid particles at different Reynolds numbers by two-dimensional smoothed particle hydrodynamics","authors":"Domenico Davide Meringolo,&nbsp;Sergio Servidio,&nbsp;Claudio Meringolo,&nbsp;Francesco Aristodemo,&nbsp;Pasquale Giuseppe F. Filianoti,&nbsp;Paolo Veltri,&nbsp;Vincenzo Carbone","doi":"10.1007/s40571-024-00863-3","DOIUrl":"10.1007/s40571-024-00863-3","url":null,"abstract":"<div><p>We perform turbulence simulations through the smoothed particle hydrodynamics (SPH) in a two-dimensional (2D) reduced geometry. By starting from a simple Taylor–Green vortex, we vary the Reynolds number, following the transition of the flow dynamics to turbulence. The same Reynolds numbers are reproduced for random initial conditions, which show an easier triggering of turbulence. The statistical analysis of the pair-particles distance separation is performed in order to characterize such transition, revealing that, in the more viscous case, the large-scale main structures of the initial vortex survive to the cascade, as typical of low-order, chaotic systems. At high Reynolds numbers, instead, the initial structure is broken and the system experiences turbulence. In this regime, the SPH particles manifest the classical Richardson law of turbulence, with an explosive pair-particles departure. This work might be relevant for 2D applications of hydrodynamics, to understand the chaos-turbulence transitions.\u0000</p></div>","PeriodicalId":524,"journal":{"name":"Computational Particle Mechanics","volume":"12 2","pages":"1155 - 1168"},"PeriodicalIF":2.8,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143918998","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 synthetic study of cracking behavior and fracture mechanism of sandstone containing two non-connected fissures under uniaxial compression","authors":"Wenqiang Ma,&nbsp;Yanghao Ma","doi":"10.1007/s40571-024-00858-0","DOIUrl":"10.1007/s40571-024-00858-0","url":null,"abstract":"<div><p>Rock mass always undergone multiple geological activities, leaving behind various kinds of fissures in it. To investigate the influence of the non-connected fissures on the cracking behavior and fracture process of rock mass, experimental and numerical investigations were performed on sandstone containing two non-connected fissures, but of different fissure geometric configurations. The progressive cracking behavior and full-field strain evolution were analyzed through the mechanical-acousto-optical methods, while the stress evolution was studied by the particle flow code modeling. The results indicate that the cracks start to incubate at the tips of the prefabricated fissures in elastic deformation stage, then initiate and propagate to form megascopic fractures during stable crack propagation stage, finally rapidly intersect and expand to sample boundary at unstable crack propagation stage, forming the ultimate macro-fracture surface. The inclination angle (<i>α</i>) of fissure ① has significant influence on the crack type and number. The acousto-optical responses and stress field evolution both suggest that tensile cracks gradually decrease and shear cracks increase with increasing <i>α</i>, indicating a transformation from tensile failure to shear failure. As the tensile strength of rock is lower than shear strength, therefore, the uniaxial compressive strength and Young's modulus values both increase with increasing <i>α</i>. Besides, the spatio-temporal evolution of cracks and the failure modes from numerical simulation conform well to the laboratory testing results. The findings enrich the study on the fracture and failure mechanism of rock masses containing non-connected fissures, which is of great significance for rock engineering safety.</p></div>","PeriodicalId":524,"journal":{"name":"Computational Particle Mechanics","volume":"12 2","pages":"1075 - 1097"},"PeriodicalIF":2.8,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143918920","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}