Improved Contact Bond Model of Discrete Element Method for Simulating Strain Rate Effect of Rock Materials

2021 ◽  
pp. 572-580
Author(s):  
Y. Zhao ◽  
G. Y. Zhao ◽  
J. Zhou
Keyword(s):  
Discrete Element Method ◽  
Strain Rate ◽  
Discrete Element ◽  
Strain Rate Effect ◽  
Rate Effect ◽  
Rock Materials ◽  
Bond Model ◽  
Element Method

scholarly journals Prediction of flowability of cohesive powder mixtures at high strain rate conditions by discrete element method

2020 ◽  
Vol 372 ◽  
pp. 59-67
Author(s):  
Mehrdad Pasha ◽  
Nurul Lukman Hekiem ◽  
Xiaodong Jia ◽  
Mojtaba Ghadiri
Keyword(s):  
Discrete Element Method ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Discrete Element ◽  
Powder Mixtures ◽  
Cohesive Powder ◽  
Element Method

Nonlinear Dynamic Analysis of Space Frame Structures by Discrete Element Method

2014 ◽  
Vol 638-640 ◽  
pp. 1716-1719 ◽  
Author(s):  
Nian Qi ◽  
Ji Hong Ye
Keyword(s):  
Discrete Element Method ◽  
Dynamic Analysis ◽  
Nonlinear Dynamic ◽  
Nonlinear Dynamic Analysis ◽  
Discrete Element ◽  
Internal Force ◽  
Frame Structures ◽  
Space Frame ◽  
Bond Model ◽  
Element Method

This document explores the possibility of the discrete element method (DEM) being applied in nonlinear dynamic analysis of space frame structures. The method models the analyzed object to be composed by finite particles and the Newton’s second law is applied to describe each particle’s motion. The parallel-bond model is adopted during the calculation of internal force and moment arising from the deformation. The procedure of analysis is vastly simple, accurate and versatile. Numerical examples are given to demonstrate the accuracy and applicability of this method in handling the large deflection and dynamic behaviour of space frame structures. Besides, the method does not need to form stiffness matrix or iterations, so it is more advantageous than traditional nonlinear finite element method.

scholarly journals A modified bond model for describing isotropic linear elastic material behaviour with the discrete element method

2021 ◽  
Author(s):  
Rahav Gowtham Venkateswaran ◽  
Ursula Kowalsky ◽  
Dieter Dinkler
Keyword(s):  
Discrete Element Method ◽  
Elastic Material ◽  
Poisson’S Ratio ◽  
Strain Energy ◽  
Discrete Element ◽  
Poisson's Ratio ◽  
Linear Elastic Material ◽  
Linear Elastic ◽  
Bond Model ◽  
Element Method

AbstractRecently, the discrete element method is increasingly being used for describing the behaviour of isotropic linear elastic materials. However, the common bond models employed to describe the interaction between particles restrict the range of Poisson’s ratio that can be represented. In this paper, to overcome the restriction, a modified bond model that includes the coupling of shear strain energy of neighbouring bonds is proposed. The coupling is described by a multi-bond term that enables the model to distinguish between shear deformations and rigid-body rotations. The positive definiteness of the strain energy function of the modified bond model is verified. To validate the model, uniaxial tension, pure shear and pure bending tests are performed. Comparison of the particle displacements with continuum mechanics solution demonstrates the ability of the model to describe the behaviour of isotropic linear elastic material for values of Poisson’s ratio in the range $$0 \le \nu < 0.5$$ 0 ≤ ν < 0.5 .

scholarly journals Discrete Element Method Modeling for the Failure Analysis of Dry Mono-Size Coke Aggregates

2021 ◽  
Author(s):  
Alireza Sadeghi Chahardeh ◽  
Roozbeh Mollaabbasi ◽  
Donald Picard ◽  
Seyed Mohammad Taghavi ◽  
Houshang Alamdari
Keyword(s):  
Discrete Element Method ◽  
Failure Analysis ◽  
Strain Rate ◽  
Confining Pressure ◽  
Discrete Element ◽  
Second Order ◽  
Operating Conditions ◽  
Compaction Process ◽  
Carbon Anodes ◽  
Element Method

An in-depth study of the failure of granular materials, which is known as a mechanism to generate defects, can reveal the facts about the origin of the imperfections such as cracks in the carbon anodes. The initiation and propagation of the cracks in the carbon anode, especially the horizontal cracks below the stub-holes, reduce the anode efficiency during the electrolysis process. In order to avoid the formation of cracks in the carbon anodes, the failure analysis of coke aggregates can be employed to determine the appropriate recipe and operating conditions. In this paper, it will be shown that a particular failure mode can be responsible for the crack generation in the carbon anodes. The second-order work criterion is employed to analyze the failure of the coke aggregate specimens and the relationships between the second-order work, the kinetic energy, and the instability of the granular material are investigated. In addition, the coke aggregates are modeled by exploiting the discrete element method (DEM) to reveal the micro-mechanical behavior of the dry coke aggregates during the compaction process. The optimal number of particles required for the failure analysis in the DEM simulations is determined. The effects of the confining pressure and the strain rate as two important compaction process parameters on the failure are studied. The results reveal that increasing the confining pressure enhances the probability of the diffusing mode of the failure in the specimen. On the other hand, the increase of strain rate augments the chance of the strain localization mode of the failure in the specimen.

Simulation of Coal Mechanical Characteristics with Discrete Element Method

2013 ◽  
Vol 671-674 ◽  
pp. 117-121
Author(s):  
Song Yong Liu ◽  
Hong Xiang Jiang ◽  
Kui Dong Gao
Keyword(s):  
Discrete Element Method ◽  
Mechanical Characteristics ◽  
Discrete Element ◽  
Particle Flow Code ◽  
Experimental Result ◽  
Uniaxial Compression Test ◽  
Micro Particles ◽  
Bond Model ◽  
Dem Model ◽  
Element Method

Base on the parallel-bond model in PFC2D(Particle Flow Code in two Dimension) used to describe the contact between coal micro-particles, DEM(Discrete Element Method) model of coal has been established, so that the coal uniaxial compression test could be investigated. By comparing the simulation result and experimental result, it is clear that DEM is suitable to simulate the mechanical characteristics and failure mode of coal. The effects of micro-parameters on the constitutive behaviors of coal simulation sample are discussed, they can provide basis for designing DEM model of other analogous coals with differenet mechanical characteristics. The microparameters of coal DEM model obtained in simulation test could be a guilding role for further developing the applicability of the DEM in coal mining, crushing and some other aspects.

scholarly journals Discrete Element Method Modeling for the Failure Analysis of Dry Mono-Size Coke Aggregates

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2174
Author(s):  
Alireza Sadeghi-Chahardeh ◽  
Roozbeh Mollaabbasi ◽  
Donald Picard ◽  
Seyed Mohammad Taghavi ◽  
Houshang Alamdari
Keyword(s):  
Discrete Element Method ◽  
Failure Analysis ◽  
Strain Rate ◽  
Confining Pressure ◽  
Discrete Element ◽  
Second Order ◽  
Operating Conditions ◽  
Compaction Process ◽  
Carbon Anodes ◽  
Element Method

An in-depth study of the failure of granular materials, which is known as a mechanism to generate defects, can reveal the facts regarding the origin of the imperfections, such as cracks in the carbon anodes. The initiation and propagation of the cracks in the carbon anode, especially the horizontal cracks below the stub-holes, reduce the anode efficiency during the electrolysis process. The failure analysis of coke aggregates can be employed to determine the appropriate recipe and operating conditions in order to avoid the formation of cracks in the carbon anodes. In this paper, it will be shown that a particular failure mode can be responsible for the crack generation in the carbon anodes. The second-order work criterion is employed to analyze the failure of the coke aggregate specimens and the relationships between the second-order work, the kinetic energy, and the instability of the granular material are investigated. In addition, the coke aggregates are modeled by exploiting the discrete element method (DEM) to reveal the micro-mechanical behavior of the dry coke aggregates during the compaction process. The optimal number of particles required for the failure analysis in the DEM simulations is determined. The effects of the confining pressure and strain rate as two important compaction process parameters on the failure are studied. The results reveal that increasing the confining pressure enhances the probability of the diffusing mode of the failure in the specimen. On the other hand, the increase of strain rate augments the chance of the strain localization mode of the failure in the specimen.

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