Contact force model including the liquid-bridge force for wet-particle simulation using the discrete element method

2016 ◽  
Vol 27 (2) ◽  
pp. 652-660 ◽  
Author(s):  
Yuki Tsunazawa ◽  
Daiki Fujihashi ◽  
Sho Fukui ◽  
Mikio Sakai ◽  
Chiharu Tokoro
Keyword(s):  
Discrete Element Method ◽  
Contact Force ◽  
Liquid Bridge ◽  
Discrete Element ◽  
Particle Simulation ◽  
Force Model ◽  
Contact Force Model ◽  
Element Method

Tangential Force Model for the Combined Finite-Discrete Element Method

2019 ◽  
Vol 17 (09) ◽  
pp. 1950068
Author(s):  
Xunnan Liu ◽  
Lanhao Zhao ◽  
Jia Mao ◽  
Tongchun Li
Keyword(s):  
Discrete Element Method ◽  
Contact Interaction ◽  
Contact Force ◽  
Tangential Force ◽  
Numerical Test ◽  
Discrete Element ◽  
Force Model ◽  
Normal Contact ◽  
Tangential Contact ◽  
Element Method

In the past, contact model in the combined finite-discrete element method (FDEM) does not include the influence of the tangential contact interaction, and the deficient model associated with the contact force can seriously degrade the computing accuracy. In order to overcome this defect, an improved FDEM is developed in this work. The potential contact mechanism is implemented to calculate the normal contact force; meanwhile, the force-displacement law by coupling the classical Mohr–Coulomb type frictional algorithm and the rotation transformation algorithm is applied for the accurate computation of the tangential contact force. Consequently, a holonomic system of the calculation algorithm for the contact interaction is proposed, accounting for the influence of the tangential contact force. The performance of the approach is validated with well-known benchmarks including a frictional numerical test, the dynamic response of the block under the seismic excitation, a sliding/toppling test of a joint rock slope, a numerical simulation for joints structure affecting a sliding rock mass and the 2008 Donghekou Landslide trigged by the Wenchuan Earthquake. The results are compared against the experimental data and analytical solutions. Excellent agreements between the computational result and existing measurements show that the proposed approach has an outstanding ability to describe the complex mechanical properties among the separate entities.

Simulation of Pressing Effect of Press Wheel with Different Rims by Discrete Element Method

2011 ◽  
Vol 101-102 ◽  
pp. 551-555
Author(s):  
Fu Lan Wang ◽  
Hong Lei Jia ◽  
Dan Dan Liu
Keyword(s):  
Discrete Element Method ◽  
Contact Force ◽  
Discrete Element ◽  
Soil Displacement ◽  
The Press ◽  
Better Than ◽  
Element Method

Pressing is an important part of precision seeding operation, which has an important effect on crushing soil. In order to enhancing the effect of soil crushing, some press wheels with flange rim are used. But further research is needed to evaluate whether the use of these press wheels affect the actual seeding depth that will affect precision seeding quality. Three kinds of press wheels, with the smooth rim, circular flange rim and rib rim respectively were designed, and the PFC3D discrete element method (DEM) software was used to simulate the pressing processes of these press wheels, and the contact force between the rim and soil, soil displacement and porosity were analyzed. It was concluded that the press wheel with the smooth rim is better than others in precision seeding operation.

scholarly journals A Dynamic Coarse Grain Discrete Element Method for Gas-Solid Fluidized Beds by Considering Particle-Group Crushing and Polymerization

2020 ◽  
Vol 10 (6) ◽  
pp. 1943
Author(s):  
Xiaodong Wang ◽  
Kai Chen ◽  
Ting Kang ◽  
Jie Ouyang
Keyword(s):  
Discrete Element Method ◽  
Fluidized Beds ◽  
Stokes Equations ◽  
Discrete Element ◽  
Coarse Grain ◽  
Equivalent Diameter ◽  
Force Model ◽  
Simpler Algorithm ◽  
Particle Group ◽  
Element Method

The discrete element method (DEM) coupled with computational fluid dynamics (CFD) is used extensively for the numerical simulation of gas-solid fluidized beds. In order to improve the efficiency of this approach, a coarse grain model of the DEM was proposed in the literature. In this model, a group of original particles are treated as a large-sized particle based on the initial particle distribution, and during the whole simulation process the number and components of these particle-groups remain unchanged. However, collisions between particles can lead to frequent crushing and polymerization of particle-groups. This fact has typically been ignored, so the purpose of this paper is to rationalize the coarse grain DEM-CFD model by considering the dynamic particle-group crushing and polymerization. In particular, the effective size of each particle-group is measured by a quantity called equivalent particle-group diameter, whose definition references the equivalent cluster diameter used by the energy-minimization multi-scale (EMMS) model. Then a particle-group crushing criterion is presented based on the mismatch between the equivalent diameter and actual diameter of a particle-group. As to the polymerization of two colliding particle-groups, their velocity difference after collision is chosen as a criterion. Moreover, considering the flow heterogeneity induced by the particle cluster formation, the EMMS drag force model is adopted in this work. Simulations are carried out by using a finite volume method (FVM) with non-staggered grids. For decoupling the Navier-Stokes equations, the semi-implicit method for pressure linked equations revised (SIMPLER) algorithm is used. The simulation results show that the proposed dynamic coarse grain DEM-CFD method has better performance than the original one.

scholarly journals Chrono::GPU: An Open-Source Simulation Package for Granular Dynamics Using the Discrete Element Method

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1813
Author(s):  
Luning Fang ◽  
Ruochun Zhang ◽  
Colin Vanden Vanden Heuvel ◽  
Radu Serban ◽  
Dan Negrut
Keyword(s):  
Discrete Element Method ◽  
Open Source ◽  
Discrete Element ◽  
Mixed Data ◽  
Tangential Displacement ◽  
Force Model ◽  
Processing Unit ◽  
Granular Dynamics ◽  
Simulation Engine ◽  
Element Method

We report on an open-source, publicly available C++ software module called Chrono::GPU, which uses the Discrete Element Method (DEM) to simulate large granular systems on Graphics Processing Unit (GPU) cards. The solver supports the integration of granular material with geometries defined by triangle meshes, as well as co-simulation with the multi-physics simulation engine Chrono. Chrono::GPU adopts a smooth contact formulation and implements various common contact force models, such as the Hertzian model for normal force and the Mindlin friction force model, which takes into account the history of tangential displacement, rolling frictional torques, and cohesion. We report on the code structure and highlight its use of mixed data types for reducing the memory footprint and increasing simulation speed. We discuss several validation tests (wave propagation, rotating drum, direct shear test, crater test) that compare the simulation results against experimental data or results reported in the literature. In another benchmark test, we demonstrate linear scaling with a problem size up to the GPU memory capacity; specifically, for systems with 130 million DEM elements. The simulation infrastructure is demonstrated in conjunction with simulations of the NASA Curiosity rover, which is currently active on Mars.

Force model considerations for glued-sphere discrete element method simulations

2009 ◽  
Vol 64 (15) ◽  
pp. 3466-3475 ◽  
Author(s):  
Madhusudhan Kodam ◽  
Rahul Bharadwaj ◽  
Jennifer Curtis ◽  
Bruno Hancock ◽  
Carl Wassgren
Keyword(s):  
Discrete Element Method ◽  
Discrete Element ◽  
Force Model ◽  
Element Method
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