scholarly journals Modelling of Rock Cutting with Asymmetrical Disc Tool Using Discrete-Element Method (DEM)

2021 ◽  
Author(s):  
Grzegorz Stopka
Keyword(s):  
Discrete Element Method ◽  
Simulation Model ◽  
Laboratory Tests ◽  
Experimental Studies ◽  
Deep Understanding ◽  
Discrete Element ◽  
Rock Cutting ◽  
Analytical Models ◽  
Mining Methods ◽  
Element Method

AbstractThe use of asymmetrical disc tools for the mining of hard and very hard rocks is a promising direction for developing mechanical mining methods. A significant obstacle in developing mining methods with the use of asymmetric disc tools is the lack of adequate computational methods. A deep understanding of rock–tool interaction can develop industrial applications of asymmetric disc tools significantly. The fundamental problem in designing work systems with asymmetric disc tools is the lack of adequate analytical models to identify tool loads during the mining process. One reasonable approach is to use computer simulation. The purpose of the research was to develop a simulation model of rock cutting using an asymmetrical disc tool and then evaluate the developed model. In the article, the Discrete-Element Method (DEM) in LS-Dyna was adopted to simulate rock cutting with asymmetrical disc tools. Numerical tests were conducted by pushing the disc into a rock sample at a given distance from the sample edge until the material was detached entirely. Two types of rock samples were used in the simulation tests: concrete and sandstone. The independent variables in the study were the disc diameter and the cut spacing. To validate the simulation model, analogous laboratory tests were carried out. The article presents a comparison of the results of simulation and laboratory tests. The given comparison showed good accordance LS-Dyna model with the experimental studies. The proposed test results can be input data for developing simulation models on a larger scale. Thus, it will be possible to consider the complex kinematics of the dynamics of the rock-mining process with disc tools using the DEM simulation.

Numerical study of sheared mobile polydisperse sediment beds with a coupled lattice Boltzmann - discrete element method

2021 ◽  
Author(s):  
Christoph Rettinger ◽  
Sebastian Eibl ◽  
Ulrich Rüde ◽  
Bernhard Vowinckel
Keyword(s):  
Discrete Element Method ◽  
Lattice Boltzmann ◽  
Numerical Study ◽  
Experimental Studies ◽  
Discrete Element ◽  
Parallel Execution ◽  
Coupling Mechanism ◽  
Size Segregation ◽  
Minimum Diameter ◽  
Element Method

<p>With the increasing computational power of today's supercomputers, geometrically fully resolved simulations of particle-laden flows are becoming a viable alternative to laboratory experiments. Such simulations enable detailed investigations of transport phenomena in various multiphysics scenarios, such as the coupled interaction of sediment beds with a shearing fluid flow. There, the majority of available simulations as well as experimental studies focuses on setups of monodisperse particles. In reality, however, polydisperse configurations are much more common and feature unique effects like vertical size segregation.</p><p>In this talk, we will present numerical studies of mobile polydisperse sediment beds in a laminar shear flow, with a ratio of maximum to minimum diameter up to 10. The lattice Boltzmann method is applied to represent the fluid dynamics through and above the sediment bed efficiently. We model particle interactions by a discrete element method and explicitly account for lubrication forces. The fluid-particle coupling mechanism is based on the geometrically fully resolved momentum transfer between the fluid and the particulate phase. We will highlight algorithmic aspects and communication schemes essential for massively parallel execution.</p><p>Utilizing these capabilities allows us to achieve large-scale simulations with more than 26.000 densely-packed polydisperse particles interacting with the fluid. With this, we are able to reproduce effects like size segregation and to study the rheological behavior of such systems in great detail. We will evaluate and discuss the influence of polydispersity on these processes. These insights will be used to improve and extend existing macroscopic models.</p>

scholarly journals A Simulation Model for Determining the Mechanical Properties of Rapeseed using the Discrete Element Method

2015 ◽  
Vol 59 (4) ◽  
pp. 575-582 ◽  
Author(s):  
Kornél Tamás ◽  
Bernát Földesi ◽  
János Péter Rádics ◽  
István J. Jóri ◽  
László Fenyvesi
Keyword(s):  
Mechanical Properties ◽  
Discrete Element Method ◽  
Simulation Model ◽  
Discrete Element ◽  
Element Method

Applicable Contact Force Models for the Discrete Element Method: The Single Particle Perspective

2008 ◽  
Vol 131 (2) ◽  
Author(s):  
H. Kruggel-Emden ◽  
S. Wirtz ◽  
V. Scherer
Keyword(s):  
Discrete Element Method ◽  
Granular Materials ◽  
Experimental Studies ◽  
Spherical Shape ◽  
Discrete Element ◽  
Industrial Applications ◽  
Contact Forces ◽  
Experimental Investigations ◽  
Simulation Techniques ◽  
Element Method

Several processes in nature as well as many industrial applications involve static or dynamic granular materials. Granulates can adopt solid-, liquid-, or gaslike states and thereby reveal intriguing physical phenomena not observable in its versatility for any other form of matter. The frequent occurrence of phase transitions and the related characteristics thereby strongly affect their processing quality and economics. This situation demands for prediction methods for the behavior of granulates. In this context simulations provide a feasible alternative to experimental investigations. Several different simulation approaches are applicable to granular materials. The time-driven discrete element method turns out to be not only the most complex but also the most general simulation approach. Discrete element simulations have been used in a wide variety of scientific fields for more than 30 years. With the tremendous increase in available computer power, especially in the past years, the method is more and more developing to the state of the art simulation technique for granular materials not only in science but also in industrial applications. Several commercial software packages utilizing the time-driven discrete element method have emerged and are becoming more and more popular within the engineering community. Despite the long time of usage of the time-driven discrete element method, model advances derived and theoretical and experimental studies performed in the different branches of application lack harmonization. They thereby provide potential for improvements. Therefore, the scope of this paper is a review of methods and models for contact forces based on theoretical considerations and experimental data from literature. Particles considered are of spherical shape. Through model advances it is intended to contribute to a general enhancement of simulation techniques, which help improve products and the design of the related equipment.

Structural Analysis and Optimization of Mechanical Excavator WK-20 Bucket Based on Discrete Element Method

2014 ◽  
Vol 563 ◽  
pp. 284-287
Author(s):  
Ya Juan Hou ◽  
Ai Feng Li ◽  
Su He Gao ◽  
Guo Qiang Wang
Keyword(s):  
Structural Analysis ◽  
Discrete Element Method ◽  
Simulation Model ◽  
Theoretical Basis ◽  
Reliable Method ◽  
Structural Characteristics ◽  
Discrete Element ◽  
Simulation And Optimization ◽  
Filling Coefficient ◽  
Element Method

The structural characteristics and requirements of a bucket, combined with the working experience of an excavator, were analyzed to optimize the structure of a WK-20 bucket. The simulation model was defined by the discrete element method (DEM) to characterize the real interaction between the bucket and different materials. Through an analysis and comparison of the performance of the original and optimized buckets, the latter increased the filling coefficient for different materials. The simulation and optimization based on DEM offered the theoretical basis and a reliable method for the reasonable design of the bucket structure and the entire machine.

scholarly journals Pelletizing Analysis on MgO-Fluxed Pellets by DEM

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 821
Author(s):  
Fang Long ◽  
Fengman Shen ◽  
Xin Jiang ◽  
Fu Yang ◽  
Yulu Zhou ◽  
...  
Keyword(s):  
Discrete Element Method ◽  
Simulation Model ◽  
Tilt Angle ◽  
Rotational Speed ◽  
Discrete Element ◽  
Charge Ratio ◽  
Simulation Results ◽  
Fluxed Pellets ◽  
Element Method

The Discrete Element Method (DEM) was used to analyze the pelletization process of MgO-fluxed pellets. The effects of the charge ratio and rotational speed of the disc pelletizer on the behavior of MgO-fluxed pellets were investigated by using a simulation. The simulation results show that under the condition of a certain tilt angle of the disc pelletizer (the tilt angle is 49°), the suitable parameters of the disc pelletizer are that the charge ratio is 20% and the rotational speedis 0.7 N/NC. This simulation model proposed will be useful to research pellets behavior and for the design of disc pelletizers.

The Research of the Numerical Simulation on the Granular Ballast Bed Tamping

2012 ◽  
Vol 479-481 ◽  
pp. 1395-1398 ◽  
Author(s):  
Xue Jun Wang ◽  
Yi Lin Chi ◽  
Wei Li ◽  
Tao Yong Zhou ◽  
Xing Li Geng
Keyword(s):  
Discrete Element Method ◽  
Simulation Model ◽  
High Speed ◽  
Flow Simulation ◽  
Discrete Element ◽  
Particle Flow ◽  
Main Work ◽  
Railway Sleeper ◽  
Particle Flow Simulation ◽  
Element Method

Abstract. Under the action of high speed train and the repeated heavy vehicles, the granular ballast bed produce degradation and deformation that do not restore, tamping homework is an effective method that is being used to recovery the elastic of the track. In this article, the discrete element method is be used to establish a cross discrete particle flow simulation model between ballast track bed and tamping picks, and to simulate the movement and vibration characteristics of the granular ballast particles while tamping. The three main work are included in this paper. With the large commercial software EDEM, the first main work is to research the modeling method of ballast particles. The second work is to establish firm-soft coupling particle flow simulation model among ballast 、sleeper and tamping picks. The third work is to validate the ballasts' mechanical properties' change rule under the railway sleeper, while different tamping working condition and out load are being implemented. The research shows the discrete element method is effective for solving the vibration problem produced during the process of tamping homework.

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