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Enhancing discrete element model accuracy for lunar soil: Calibration and validation of mesoscopic parameters

PLANETARY AND SPACE SCIENCE 2025年 255卷

作者： Bu, Xianghui Li, Yuqiong Li, Na Ying, Liping Yuan, Zheng Han, Zongfang Xu, Xiuli Nanjing Tech Univ Coll Civil Engn Nanjing 211800 Peoples R China Chinese Acad Sci Key Lab Mech Fluid Solid Coupling Syst Inst Mech Beijing 100190 Peoples R China Chinese Acad Sci Inst Mech State Key Lab Nonlinear Mech Beijing 100190 Peoples R China Guangdong Aerosp Res Acad Nan Sha Guangzhou 511458 Nan Sha Peoples R China

To enhance the precision of the discrete element model for lunar soil-tool simulation work, this paper introduces a novel discrete element model of lunar soil incorporating particle shape and the van der Waals forces between particles. The effect of mesoscopic parameters on peak stress and failure point are systematically calibrated in the model by triaxial compression stress-strain curves. The results show that six meso-parameters have significant impact on the mechanical response of the model, including effective modulus, rolling friction coefficient, normalto-shear stiffness ratio, damping coefficient, maximum attractive force and attraction range. The model accurately simulates complex mechanical behavior in both loose, dense lunar soils and soil-tool interaction. This study lays a foundation for future lunar soil-anchor interaction simulation and the interpretation of lunar soil mechanical parameters.

关键词： Lunar soil discrete element model Mesoscopic parameters Van der waals force

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modeling hard rock breakage behavior influenced by the tipped hob cutter's tooth structure using the 2D discrete element (DE) model

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POWDER TECHNOLOGY 2025年 449卷

作者： Wang, Zhenyu Tong, Jinghui Zhang, Xin Sheng, Feng Gao, Yongqin Zheng, Kehong Qiu, Bingjing Zhejiang Univ Coll Civil Engn & Architecture Hangzhou 310058 Peoples R China Ctr Sinohydro Bur 12 Co LTD Hangzhou Peoples R China Zhejiang Scitech Univ Hangzhou Coll Mech Engn Xiasha 310018 Zhejiang Peoples R China Zhejiang Univ Ctr Hypergrav Expt & Interdisciplinary Res Hangzhou 310058 Peoples R China

A deep understanding of the mesoscopic damage evolution mechanism of tipped hob cutter in hard rock, as influenced by tooth structure parameters and working parameters, can assist in optimizing the tooth of tipped hob cutter and uncovering the failure conditions and mechanism of rock. In this paper, a series of numerical simulations of rock breaking by tipped hob cutter's tooth were modelled, calibrated, and analyzed to investigate the failure conditions and mechanism of rock by tipped hob cutter, as well as the effects of tooth profiles and working parameters on the fracture evolution of hard rock. The results show that the most efficient combination of tooth profile and Dp differs depending on the rock types. D-type teeth with a penetration depth of Dp = 3 mm are optimal for crushing granite, while A-type teeth with a penetration depth of Dp = 4 mm are suitable for crushing sandstone.

关键词： Raise boring machine discrete element model Hard rock damage behavior Tipped hob cutter Cutter tooth structure Hob working parameters

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discrete element model for performance analysis of cutterhead excavation system of EPB machine

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TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY 2013年 37卷 37-44页

作者： Wu, Li Guan, Tianmin Lei, Lei Dalian Jiaotong Univ Inst Engn Mech Dalian Peoples R China

With the aim of probing for design theory of cutterhead excavation system of earth pressure balance (EPB) machine, the parameters representing the system performance are concluded firstly. Then a 3D model for cutterhead excavation system of EPB machine is presented with the discrete element method (DEM) software PFC3D, which is capable of simulating the tunneling ground in site, the machine structure and the excavation operation. The performance parameters indicating stability of excavation face, soil discharging rate, cutterhead system torque and cutter wear are measured by running the DEM code. The results obtained with the DEM model are accord with situ data. It indicates that the DEM model is a promising method replacing the field experiment to analyze the influences of the structural parameters on system performances, which are essential for structure optimization design of the cutterhead system of EPB machine. (C) 2013 Elsevier Ltd. All rights reserved.

关键词： Cutterhead Earth pressure balance discrete element model Performance Design

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discrete element model for the anisotropic cracking of shrinking material layers

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INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES 2024年 299卷

作者： Szatmari, Roland Halasz, Zoltan Nakahara, Akio Kitsunezaki, So Kun, Ferenc Univ Debrecen Fac Sci & Technol Doctoral Sch Phys Dept Expt Phys POB 400 H-4002 Debrecen Hungary Inst Nucl Res Atomki POB 51 H-4001 Debrecen Hungary Nihon Univ Coll Sci & Technol Lab Phys 7-24-1 Narashinodai Funabashi 2748501 Japan Fac Nara Womens Univ Div Nat Sci Res Grp Phys Nara 6308506 Japan Univ Debrecen Fac Sci & Technol Doctoral Sch Phys Dept Theoret Phys POB 400 H-4002 Debrecen Hungary

Mechanical perturbation of thin layers of pastes on a substrate results in anisotropic cracking during desiccation which allows for a controlled generation of crack patterns with a high relevance for industrial applications. In the present paper we propose a modeling framework to capture the anisotropy induced by initial perturbations which imprint directional dependent material features into the layer. Our approach is based on a random tessellation of the layer using convex polygons which are made anisotropic by elongating or compressing them along the direction of perturbation. Physical properties of the particles' cohesive contacts are determined by the geometrical characteristics of polygons giving rise to a well controlled anisotropy in the mechanical response of the material and in the structure of the fracture pattern emerging during shrinking. The main advantage of the approach is that both the structural disorder of the layer and the strength of anisotropy are controlled by a single parameter. Based on computer simulations we demonstrate that varying its two parameters the model reproduces the qualitative features of experimental findings and provides advantages over existing modeling approaches.

关键词： Shrinkage induced cracking discrete element model Random lattice Anisotropic discretization Direction dependent crack formation

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discrete element model for cracking in defective ceramics under uniaxial compression

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COMPUTATIONAL PARTICLE MECHANICS 2024年第4期11卷 1565-1577页

作者： Li, Yafeng Wang, Lei Gao, Hongfei Zhang, Jing Tiangong Univ Tianjin Key Lab Adv Mechatron Equipment Technol Tianjin 300387 Peoples R China Tiangong Univ Sch Mech Engn Tianjin 300387 Peoples R China Indiana Univ Purdue Univ Dept Mech & Energy Engn Indianapolis IN 46202 USA

In this study, an improved discrete element model (DEM) is developed to understand the defect effect in ceramic cracking process. First, model parameters based on the linear parallel bonding model are calibrated using microcell deformation experiments and orthogonal experimental design methods. Then, the uniaxial compression of ceramics with different crack lengths and inclination angles are simulated. The crack initiation and propagation processes are illustrated with displacement and stress fields. The results show the predicted crack patterns are qualitatively in agreement with experimental observations. There are two stages of crack propagation with increasing uniaxial compressive load, i.e., primary and secondary cracks. In addition, the inclination and crack length of the defects have a great influence on the mode of crack initiation and propagation, and the first crack is more likely to initiate and extend for the defects with larger crack length and smaller inclination angle.

关键词： Ceramic materials discrete element model Uniaxial compression Crack propagation Mechanical properties

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Simulation of ice accumulation around bridge piers during river breakup periods using a discrete element model

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Journal of Hydrodynamics 2022年第1期34卷 94-105页

作者： Tie-jie Cheng Jun Wang Pang-pang Chen Jueyi Sui School of Civil and Hydraulic Engineering Hefei University of TechnologyHefei230009China School of Engineering University of Northern British ColumbiaPrince GeorgeBCCanada

During river breakup periods in winter or early spring, a large amount of ice floes of various sizes will be transported by flowing water. The presence of bridge piers in water alters velocity field. As a consequence, the transport process of ice floes around bridge piers will be influenced. It often causes the ice floe congestion around bridge piers. In the present study, the influences of the ice floe size and coverage ratio of ice floating on water surface on ice floe congestion have been examined. The influence of bridge pier layout on ice jam development has been assessed. Results showed that during river breakup period, the ice floe transport capacity around bridge pier decreased. With the presence of bridge piers, the critical coverage ratio of ice floating on water surface for the ice floe congestion depends on the ratio of the side length of ice floe to the pier spacing distance (a / Ln) and ice floe-length Froude number associated with the ice floe length (Fra). A discrete element model (DEM) has been developed to simulate the ice floe accumulating process around bridge piers. Simulation results agree well with those of experiments.

关键词： Bridge pier coverage ratio of floating ice discrete element model ice jam river breakup

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A new discrete element model for the evaluation of the seismic behaviour of unreinforced masonry buildings

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ENGINEERING STRUCTURES 2012年 40卷 327-338页

作者： Calio, Ivo Marletta, Massimo Panto, Bartolomeo Univ Catania Dept Civil & Environm Engn I-95125 Catania Italy

The evaluation of the nonlinear seismic response of masonry buildings represents a subject of considerable importance whose resolution is nowadays a main research topic in earthquake engineering. Refined nonlinear finite element models require a huge computational cost that makes these methods unsuitable for practical application. In this paper an innovative discrete-element model, conceived for the simulation of the in-plane behaviour of masonry buildings, is presented. The basic idea of the proposed approach is to approximate the in-plane nonlinear response of masonry walls by an equivalent discrete element. This element is able to reproduce the typical in-plane collapse behaviour of a masonry wall subjected to earthquake loading. The reliability of the proposed approach has been evaluated by means of nonlinear incremental static analyses performed on masonry structures, for which theoretical and/or experimental results are available in the literature. The proposed computational strategy provides a relatively simple and practical tool which could be of significant value for the design and the vulnerability assessment of unreinforced masonry structures in seismic areas. (C) 2012 Elsevier Ltd. All rights reserved.

关键词： Masonry building Unreinforced Masonry structures In-plane masonry response Macro-element approach discrete element model Seismic vulnerability Nonlinear masonry analysis

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AN ADAPTIVE REDUCED-DIMENSIONAL discrete element model FOR DYNAMIC RESPONSES OF GRANULAR MATERIALS WITH HIGH-FREQUENCY NOISES

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INTERNATIONAL JOURNAL FOR MULTISCALE COMPUTATIONAL ENGINEERING 2018年第4期16卷 345-366页

作者： Zhong, Xinran Sun, WaiChing Columbia Univ Dept Civil Engn & Engn Mech 614 SW MuddMail Code 4709 New York NY 10027 USA Tongji Univ Sch Aerosp Engn & Appl Mech Shanghai 200092 Peoples R China

We present a dimensional-reduction framework based on proper orthogonal decomposition (POD) for the nondissipative explicit dynamic discrete element method (DEM) simulations. Through Galerkin projection, we introduce a finite dimensional space with lower number of degree of freedoms such that the discrete element simulations are not only faster but also free of high frequency noises. Since this method requires no injection of artificial or numerical damping, there is no need to tune damping parameters. The suppression of high frequency responses allows a larger time step for faster explicit integration. To capture the highly nonlinear behaviors due to particle rearrangement, an automatic mode-update scheme is formulated such that the most efficient basis can be used to predict mechanical responses. Numerical examples including the wave propagation simulations and uniaxial extension and compression tests are used to demonstrate the capacity of the reduced-order model.

关键词： model reduction proper orthogonal decomposition high-frequency issue dynamic responses discrete element model

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The origin of pressure oscillations in slugging fluidized beds: Comparison of experimental results from magnetic resonance imaging with a discrete element model

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CHEMICAL ENGINEERING SCIENCE 2014年 116卷 611-622页

作者： Boyce, C. M. Davidson, J. F. Holland, D. J. Scott, S. A. Dennis, J. S. Univ Cambridge Dept Chem Engn & Biotechnol Cambridge CB2 3RA England Univ Cambridge Dept Engn Cambridge CB2 1PZ England

A 3-D cylindrical discrete element model with computational fluid dynamics (DEM-CFD) was used to investigate the origin of pressure oscillations in bubbling and slugging fluidized beds in which only one bubble can erupt at a time. Beds 50 mm in diameter with various settled bed heights and superficial velocities were simulated for direct comparison with experimental results obtained using magnetic resonance imaging (MRI) and a pressure sensor (Muller et al., 2007). The theoretical predictions matched experimental results well for the frequencies of (i) pressure oscillations near the distributor and (ii) bubble eruption at the bed surface. In both model and experiment it was found that the frequency of pressure oscillations near the distributor matched the frequency of bubble eruption at the top of the bed, rather than the frequency of bubble formation at the distributor. Further simulations showed that pressure oscillations at all positions in the bed originated from the drag force imparted on the fluid by the particles, rather than from a pulse in pressure created upon bubble eruption and subsequently propagated down through the bed, as proposed by Muller et al. (2007). The theory also demonstrated that drag force and thus pressure drop was concentrated in "plugs", viz, regions packed with particles across a horizontal cross section of the bed. These regions were largest in size after bubble eruptions, causing the frequency of pressure oscillations to match that of bubble eruption. (C) 2014 The Authors. Published by Elsevier Ltd.

关键词： Fluidized beds discrete element model Pressure oscillations Slugging Computational fluid dynamics Magnetic resonance imaging

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A new 1D coupled hydrodynamic discrete element model for floating debris in violent shallow flows

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JOURNAL OF HYDRAULIC RESEARCH 2020年第5期58卷 778-789页

作者： Xiong, Yan Mahaffey, Samantha Liang, Qiuhua Rouainia, Mohamed Wang, Gang Hohai Univ State Key Lab Hydrol Water Resources & Hydraul En Nanjing Jiangsu Peoples R China Newcastle Univ Sch Engn Newcastle Upon Tyne Tyne & Wear England Loughborough Univ Sch Architecture Bldg & Civil Engn Loughborough Leics England

The effect of floating objects has so far rarely been considered in flood modelling and risk assessment, despite having significant implications for structural design in flood-prone and coastal areas. In this work, a novel two-way method is proposed to fully couple a discrete element model to a hydrodynamic model to simulate complex debris-enriched flow hydrodynamics. The adopted hydrodynamic model solves the nonlinear shallow water equations (SWEs) using a finite volume shock-capturing numerical method. After being validated against an idealized analytical test, the new coupled model is used to reproduce flume experiments of floating debris driven by dam-break waves. The numerical results agree well with the experimental measurements, demonstrating the model's capability in simulating the complex fluid-debris interactions induced by violent shallow flows.

关键词： Coupled model discrete element model extreme hydraulic conditions floating debris Godunov-type finite volume method shallow water equations

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