Improving the 3D Finite-Discrete Element Method and Its Application in the Simulation of Wheel–Sand Interactions

2018 ◽  
Vol 15 (07) ◽  
pp. 1850059 ◽  
Author(s):  
Chunlai Zhao ◽  
Mengyan Zang ◽  
Shunhua Chen ◽  
Zumei Zheng
Keyword(s):  
Finite Elements ◽  
Discrete Element Method ◽  
Size Distribution ◽  
Sphere Packing ◽  
Discrete Element ◽  
Numerical Results ◽  
Contact Detection ◽  
Discrete Elements ◽  
Contact Algorithm ◽  
Packing Algorithm

An efficient sphere-packing algorithm named hierarchical generation method (HGM) is developed. The method is capable of efficiently generating spheres with a specific size distribution in a given geometric domain. Moreover, an improved contact algorithm for contact detection between spherical discrete elements and hexahedron finite elements (INTS) is presented. The algorithm is also suitable for simulating complex wheel–sand interactions. By using the developed algorithm, the running behaviors of a chevron tread-pattern wheel on a sand bed are simulated. The sand bed model is established by HGM and wheel–sand interactions are simulated using INTS. Numerical results validate the feasibility of the proposed method in the simulation of wheel–sand interactions.

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 Modeling of Interior Ballistic Gas-Solid Flow Using a Coupled Computational Fluid Dynamics-Discrete Element Method

2013 ◽  
Vol 80 (3) ◽  
Author(s):  
Cheng Cheng ◽  
Xiaobing Zhang
Keyword(s):  
Discrete Element Method ◽  
Gas Phase ◽  
Two Phase Flow ◽  
Discrete Element ◽  
Particle Collision ◽  
Contact Detection ◽  
Reconstruction Method ◽  
Phase Flow ◽  
Two Phase ◽  
Element Method

In conventional models for two-phase reactive flow of interior ballistic, the dynamic collision phenomenon of particles is neglected or empirically simplified. However, the particle collision between particles may play an important role in dilute two-phase flow because the distribution of particles is extremely nonuniform. The collision force may be one of the key factors to influence the particle movement. This paper presents the CFD-DEM approach for simulation of interior ballistic two-phase flow considering the dynamic collision process. The gas phase is treated as a Eulerian continuum and described by a computational fluid dynamic method (CFD). The solid phase is modeled by discrete element method (DEM) using a soft sphere approach for the particle collision dynamic. The model takes into account grain combustion, particle-particle collisions, particle-wall collisions, interphase drag and heat transfer between gas and solid phases. The continuous gas phase equations are discretized in finite volume form and solved by the AUSM+-up scheme with the higher order accurate reconstruction method. Translational and rotational motions of discrete particles are solved by explicit time integrations. The direct mapping contact detection algorithm is used. The multigrid method is applied in the void fraction calculation, the contact detection procedure, and CFD solving procedure. Several verification tests demonstrate the accuracy and reliability of this approach. The simulation of an experimental igniter device in open air shows good agreement between the model and experimental measurements. This paper has implications for improving the ability to capture the complex physics phenomena of two-phase flow during the interior ballistic cycle and to predict dynamic collision phenomena at the individual particle scale.

Cell optimization for fast contact detection in the discrete element method algorithm

2007 ◽  
Vol 18 (4) ◽  
pp. 441-453 ◽  
Author(s):  
Hiroshi Mio ◽  
Atsuko Shimosaka ◽  
Yoshiyuki Shirakawa ◽  
Jusuke Hidaka
Keyword(s):  
Discrete Element Method ◽  
Discrete Element ◽  
Contact Detection ◽  
Element Method

scholarly journals Exploring the End-Liner Forces Using DEM Software

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1047
Author(s):  
Ngonidzashe Chimwani ◽  
Murray M. Bwalya
Keyword(s):  
Discrete Element Method ◽  
Size Distribution ◽  
Ball Milling ◽  
Discrete Element ◽  
Significant Cost ◽  
Cost Component ◽  
Dem Simulation ◽  
Ball Size ◽  
Ball Motion ◽  
Simulation Scheme

The main roles of liners are to protect the mill shell and promote effective ball motion for grinding. For this reason the liner profile is carefully selected to ensure that the productivity is maximized and due liner replacement is made when this objective is no longer met. These issues have been extensively studied on shell liners as mill relining is a significant cost component of ball milling. To date, not much has been written about end-liners and the kind of forces they are subjected to. A discrete element method (DEM) simulation scheme is conducted to look at how ball size distribution, mill filling, end-liner configuration and shape affect the distribution of forces acting on the liners that were assessed to understand end-liner wear and damage. The results showed how forces varied both radially and tangentially for the different sections of end-liner, with important insights drawn for end-liner manufactures.

Cylindrical object contact detection for use in discrete element method simulations, Part II—Experimental validation

2010 ◽  
Vol 65 (22) ◽  
pp. 5863-5871 ◽  
Author(s):  
Madhusudhan Kodam ◽  
Rahul Bharadwaj ◽  
Jennifer Curtis ◽  
Bruno Hancock ◽  
Carl Wassgren
Keyword(s):  
Discrete Element Method ◽  
Experimental Validation ◽  
Discrete Element ◽  
Contact Detection ◽  
Cylindrical Object ◽  
Element Method

Simulation of Failure of a Fixed Beam Subjected to Impact Load Using Quadrilateral Discrete Element Method

2012 ◽  
Author(s):  
Rajesh P. Nair ◽  
C. Lakshmana Rao
Keyword(s):  
Discrete Element Method ◽  
Impact Analysis ◽  
Mechanical Response ◽  
Impact Load ◽  
Discrete Element ◽  
Failure Criteria ◽  
Discrete Elements ◽  
The Impact ◽  
Fixed Beam ◽  
Element Method

Discrete Element Method (DEM) is an explicit numerical scheme to model the mechanical response of solid and particulate media. In our paper, we are introducing Quadrilateral Discrete Element Method (QDEM) for the simulation of the separation of elements in fixed beam subjected to impact load. QDEM results are compared with other DEM results available in literature. Impact loads include two cases: (a) a half sine wave and (b) a penetrator hitting the fixed beam. Separation criteria used for the discrete elements is maximum principal stress failure criteria. In QDEM, convergence study for the response of fixed beam is obtained using MATLAB platform. Validation of quadrilateral elements in fixed beam is being carried out by comparing the results with empirical formula available in literature for the impact analysis.

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