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

2021 ◽  
pp. 461-468
Author(s):  
Zhiqi Zheng ◽  
Hongbo Zhao ◽  
Peng Liu ◽  
Jin He
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.

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.

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.

A Review on Application of Discrete Element Method in Soil Cutting Process

2013 ◽  
Vol 444-445 ◽  
pp. 1477-1482
Author(s):  
Ju Yang ◽  
Cheng Wu Wang ◽  
Feng Hua Wang ◽  
Xiao Jing Yang
Keyword(s):  
Discrete Element Method ◽  
Agricultural Production ◽  
Agricultural Soils ◽  
Discrete Element ◽  
Cutting Process ◽  
Basic Principles ◽  
Discrete Nature ◽  
Soil Cutting ◽  
External Forces ◽  
Element Method

Soil is one of the important mediators in the agricultural production and its particle is a discontinuous, heterogeneity and nonlinear natural geological substance. It is difficult to analyze the soil cutting process by using traditional methods. According to the discrete nature of the agricultural soils, discrete element method based on the discontinuity assumptions can be an alternative to analyze the changes under external forces in the soil cutting process. This article describes the basic principles, its applications and its prospects of the discrete element method, especially in the field of soil cutting.

Discrete element method to model cracking for two layer systems

TAPPI Journal ◽  
2019 ◽  
Vol 18 (2) ◽  
pp. 101-108
Author(s):  
Daniel Varney ◽  
Douglas Bousfield
Keyword(s):  
Discrete Element Method ◽  
Flexural Modulus ◽  
Single Layer ◽  
Discrete Element ◽  
Flexural Stress ◽  
Layer System ◽  
Three Point Bending ◽  
Moving Force ◽  
Coating Layers ◽  
Element Method

Cracking at the fold is a serious issue for many grades of coated paper and coated board. Some recent work has suggested methods to minimize this problem by using two or more coating layers of different properties. A discrete element method (DEM) has been used to model deformation events for single layer coating systems such as in-plain and out-of-plain tension, three-point bending, and a novel moving force picking simulation, but nothing has been reported related to multiple coating layers. In this paper, a DEM model has been expanded to predict the three-point bending response of a two-layer system. The main factors evaluated include the use of different binder systems in each layer and the ratio of the bottom and top layer weights. As in the past, the properties of the binder and the binder concentration are input parameters. The model can predict crack formation that is a function of these two sets of factors. In addition, the model can predict the flexural modulus, the maximum flexural stress, and the strain-at-failure. The predictions are qualitatively compared with experimental results reported in the literature.

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