Simulation of Ceramic Grinding Mechanism Based on Discrete Element Method

2019 ◽  
Vol 16 (04) ◽  
pp. 1843008 ◽  
Author(s):  
Yuanqiang Tan ◽  
Cong Zhang ◽  
Shengqiang Jiang ◽  
Y. T. Feng
Keyword(s):  
Discrete Element Method ◽  
Indentation Test ◽  
Discrete Element ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Initiation And Propagation ◽  
Grinding Mechanism ◽  
Ceramic Grinding ◽  
Cutting Model ◽  
Element Method

The grinding mechanism is the base of developing new precision machining technology, especially for brittle materials including ceramics. In previous work, many results were gained from single grit cutting model in which a grit is in contact continuously with a workpiece, similar to the indentation or scratching process, to model the material remove in grinding processing. However, the abrasives are distributed randomly on the surface of the grinding wheel, and they will impact the workpiece periodically in the grinding process. In this study, the discrete element method was introduced to simulate the mechanics behavior of [Formula: see text] ceramic. The model was validated by simulating indentation test. Both linear scratching test and pendulum scratching test have been simulated in this paper to model the grinding process. The cracks initiation and propagation were also investigated. This study has demonstrated that we should pay close attention to pendulum scratching test to explore the grinding mechanism, and concentrate on cracks initiation and propagation.

scholarly journals MAIZE STRAW CUTTING PROCESS MODELLING AND PARAMETER CALIBRATION BASED ON DISCRETE ELEMENT METHOD (DEM)

2021 ◽  
pp. 461-468
Keyword(s):  
Discrete Element Method ◽  
Shear Stiffness ◽  
Discrete Element ◽  
Cutting Process ◽  
Cutting Resistance ◽  
Maize Straw ◽  
Cutting Effect ◽  
Cutting Experiment ◽  
Cutting Model ◽  
Element Method

In order to simulate straw cutting process, this paper established a maize straw cutting model with discrete element method (DEM) based on straw cutting experiment. Firstly, maize straw model consisting of several small particles was established by DEM. Then, a straw cutting experiment was conducted and the maximum straw cutting resistance was 199 N for straw with 15 mm diameter. Then, single-factor experiment was conducted to analyze the effect of DEM parameters on straw cutting effect and the max straw cutting resistance Fmax. The normal stiffness between particles and blade (ball-facet-kn) and shear stiffness between particles and blade (ball-facet-ks) were found to be the significant factors affecting Fmax, and the value of the parameters that has no significance was determined. The optimum combination of the significant parameters was 17662 N·m-1 of ball-facet-kn and 52499 N·m-1 of ball-facet-ks. The verification test results showed that the maize straw model was cut off, thus it could simulate the real straw cutting effect, and the relative error of max straw cutting resistance Fmax between the simulation and the experiment was below 9.1%. Thus, it could be concluded that the established maize straw cutting model was accurate and reliable.

Numerical Studies of Cutting Water Saturated Sand by Discrete Element Method

2012 ◽  
Vol 256-259 ◽  
pp. 306-310 ◽  
Author(s):  
Shao Hua Qin ◽  
Li Quan Xie ◽  
Guo Jun Hong ◽  
Jie Wang
Keyword(s):  
Discrete Element Method ◽  
Sandy Loam ◽  
Static Friction ◽  
Discrete Element ◽  
Particle Flow Code ◽  
Saturated Sand ◽  
Model Soil ◽  
Water Saturated ◽  
Cutting Model ◽  
Element Method

The discrete element method (DEM) has been recognized as an effective tool to simulate soil–tool interactions. In this study, a saturated sand cutting model is developed using a commercial DEM software, Particle Flow Code in Two Dimension (PFC 2D). In the model, soil are defined as particles with the basic PFC 2D model, full coupling with a deformable fluid. The mechanical interactions between particles and also between particles and the walls are modeled by sprints, dash-pots and friction sliders. The properties of the material and interactions (Poisson’s ratio, shear modulus and density, coefficients of restitution, rolling and static friction) relate to the particle properties and not to the bulk properties. Such quantitative and qualitative models are essential for improving the design, selection and use of water saturated sand cutting implements, in different field sand under different conditions. This paper describes a numerical experimental investigation of the failure characteristics of two-dimensional water saturated sand cutting. Comprehensive simulated tests were carried out on sandy loam using a box apparatus and two model plane blades of rake angles 30º, 60º and two angles of friction 32º,42º, respectively. Besides, there are two extreme densities of the sand, compacted and loose. These factors should provide a basis for the reliable prediction of the failure type.

Numerical Simulation of Granite Sawing by Discrete Element Method

2009 ◽  
Vol 16-19 ◽  
pp. 1283-1288
Author(s):  
Yong Ye ◽  
Yuan Li ◽  
Xi Peng Xu
Keyword(s):  
Discrete Element Method ◽  
Discrete Element ◽  
Point Of View ◽  
Bending Tests ◽  
Three Point Bending ◽  
Deformation Stage ◽  
Initiation And Propagation ◽  
Discontinuous Deformation ◽  
Sawing Process ◽  
Element Method

Granite is a kind of typical discrete material, which experiences from continuous deformation stage, discontinuous deformation stage to fracture stage under sawing forces. Using discrete element method (DEM) to study the process of sawing granite will help us to understand the removal mechanism of granite from the microscopic point of view. In this paper, numerical uniaxial compression and three-point bending tests were conducted to determine the microscopic parameters of the granite specimen firstly, and then simulation was performed for sawing of the specimen. The sawing process, deformation characteristics of granite and the effect of initiation and propagation of cracks on fracture process of granite were investigated. The emphasis was laid on analyzing the variation of sawing forces under different sawing parameters. The simulation results agree well with that of experiments, indicating that DEM can reflect the external macroscopic change of granite by changing the internal microscopic structure. The conclusions in this study would be useful to the modeling of sawing processes and engineering applications.

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