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.

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.

scholarly journals Numerical Modeling of a Punch Penetration Test Using the Discrete Element Method

2020 ◽  
Vol 28 (2) ◽  
pp. 1-7
Author(s):  
Rouhollah Basirat ◽  
Jafar Khademi Hamidi
Keyword(s):  
Numerical Modeling ◽  
Discrete Element Method ◽  
Numerical Models ◽  
Confining Pressure ◽  
Discrete Element ◽  
Numerical Results ◽  
Strength Parameter ◽  
Penetration Test ◽  
Strength Parameters ◽  
Element Method

AbstractUnderstanding the brittleness of rock has a crucial importance in rock engineering applications such as the mechanical excavation of rock. In this study, numerical modeling of a punch penetration test is performed using the Discrete Element Method (DEM). The Peak Strength Index (PSI) as a function of the brittleness index was calculated using the axial load and a penetration graph obtained from numerical models. In the first step, the numerical model was verified by experimental results. The results obtained from the numerical modeling showed a good agreement with those obtained from the experimental tests. The propagation path was also simulated using Voronoi meshing. The fracture was created under the indenter in the first step, and then radial fractures were propagated. The effects of confining pressure and strength parameters on the PSI were subsequently investigated. The numerical results showed that the PSI increases with enhancing the confining pressure and the strength parameter of the rock, including cohesion and the friction angle. A new relationship between the strength parameters and PSI was also introduced based on two variable regressions of the numerical results.

scholarly journals Analysis of particle dynamics in a pin mill by Discrete Element Method

2021 ◽  
Vol 249 ◽  
pp. 07010
Author(s):  
Wei Pin Goh ◽  
Mojtaba Ghadiri
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Discrete Element Method ◽  
Discrete Element ◽  
Particle Dynamics ◽  
Operating Conditions ◽  
Impact Testing ◽  
Process Conditions ◽  
Pharmaceutical Industries ◽  
Element Method

Milling is an important process for tailoring the particle size distribution for enhanced attributes, such as dissolution, content uniformity, tableting, etc., especially for active pharmaceutical ingredients and excipients in pharmaceutical industries. Milling performance of particulate solids depends on the equipment operating conditions (geometry, process conditions and input energy etc.) as well as material properties (particle size, shape, and mechanical properties, such as Young’s modulus, hardness and fracture toughness). In this paper the particle dynamics in a pin mill is analysed using Discrete Element Method (DEM), combined with a novel approach for assessing particle breakability by single particle impact testing. A sensitivity analysis is carried out addressing the effect of the milling conditions (rotational speed and feed particle flow rate), accounting for feed mechanical properties on the breakage behaviour of the particles. Particle collision energy spectra are calculated and shown to have a distribution with the upper tail end being close to the maximum energy associated with the collision with the rings. Breakage is primarily due to collisions with the rings, except for large particles that are comparable in size with the gap between the rings, nipping is also a contributory breakage mechanism.

Discrete Element Method Modeling of the Influence of Gravity During Functional Ceramics Material Compaction Process

2010 ◽  
Vol 25 (10) ◽  
pp. 1071-1075
Author(s):  
Xia ZOU ◽  
Guo-Rong LI ◽  
Yuan-Qiang TAN ◽  
Sheng-Qiang JIANG ◽  
Liao-Ying ZHENG ◽  
...  
Keyword(s):  
Discrete Element Method ◽  
Discrete Element ◽  
Compaction Process ◽  
Functional Ceramics ◽  
Element Method

scholarly journals Analysis and Optimization of Material Flow inside the System of Rotary Coolers and Intake Pipeline via Discrete Element Method Modelling

Energies ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1849 ◽  
Author(s):  
Jakub Hlosta ◽  
David Žurovec ◽  
Jiří Rozbroj ◽  
Álvaro Ramírez-Gómez ◽  
Jan Nečas ◽  
...  
Keyword(s):  
Discrete Element Method ◽  
Material Flow ◽  
Discrete Element ◽  
Operating Conditions ◽  
Particulate Solids ◽  
Cooling Design ◽  
Pipeline Design ◽  
The Given ◽  
Fluidized Bed Boilers ◽  
Element Method

There is hardly any industry that does not use transport, storage, and processing of particulate solids in its production process. In the past, all device designs were based on empirical relationships or the designer’s experience. In the field of particulate solids, however, the discrete element method (DEM) has been increasingly used in recent years. This study shows how this simulation tool can be used in practice. More specifically, in dealing with operating problems with a rotary cooler which ensures the transport and cooling of the hot fly ash generated by combustion in fluidized bed boilers. For the given operating conditions, an analysis of the current cooling design was carried out, consisting of a non-standard intake pipeline, which divides and supplies the material to two rotary coolers. The study revealed shortcomings in both the pipeline design and the cooler design. The material was unevenly dispensed between the two coolers, which combined with the limited transport capacity of the coolers, led to overflowing and congestion of the whole system. Therefore, after visualization of the material flow and export of the necessary data using DEM design measures to mitigate these unwanted phenomena were carried out.

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