New Discrete Element Models for Three-Dimensional Impact Problems

Shan, Li; Cheng, Mengchun; Liu, Kaixin; Wei-Fu, Liu; Shi-Yang, Chen

doi:10.1088/0256-307x/26/12/120202

Cited by 12 publications

(2 citation statements)

References 6 publications

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“…Here, Δe is the error of the experiment measurement result and the simulation result, C E the experiment measurement result, and C s the simulation result. The difference is calculated, Δe = 16.85%, and the value of Δe is lower than most of the references [1][2][3][4][12][13][14][15][16]. Thus, the experimental result is consistent with the simulated one, and the mathematical model has been verified.…”

Section: Comparison Between the Results Of Verification And Experimentssupporting

confidence: 60%

Mathematical Modeling of Stray Capacitance for Planar Coil at Megahertz Frequency

Song¹,

An²,

Li³

et al. 2020

PIER M

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The coil stray capacitance is an essential factor for high-frequency coil application, such as wireless power transfer system. In this paper, in order to calculate the planar coil stray capacitance at megahertz frequency, the theory model has been built. Based on the basic capacitance calculation equation, the mathematical model has been deduced carefully. Then, the mathematical model has been evaluated by a series of simulation models. In the simulation part, the error of the variables of the theory model has also been analyzed carefully and quantitatively. In order to verify the theory and simulation model, the verification experiment has been done. The experimental results are consistent with the simulated ones and the theory model. The experimental and simulated results indicate that the theory model of the coil stray capacitance has a satisfactory accuracy, and the model has application potential in the field of wireless power transfer.

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Section: Comparison Between the Results Of Verification And Experimentssupporting

confidence: 60%

Mathematical Modeling of Stray Capacitance for Planar Coil at Megahertz Frequency

Song¹,

An²,

Li³

et al. 2020

PIER M

View full text Add to dashboard Cite

show abstract

“…The spring stiffness is derived based on the Cauchy-Born rule [39], and the details of this derivation are given in Reference [40]. A number of DE connective models were reported, for which the unit cell is either in a hexagonal structure [18,19,41] or in a cubic structure [20,[41][42][43]. In a hexagonal structure, the DE particles are stacked in a denser manner; however, the boundary of the model is not flat and, thus, not favorable for the coupling approach with the FEM.…”

Section: Connective Model: Representation Of Isotropic Elastic Solidmentioning

confidence: 99%

A Particle-Based Cohesive Crack Model for Brittle Fracture Problems

Zhang

Zhu

et al. 2020

Materials

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Numerical simulations of the fracture process are challenging, and the discrete element (DE) method is an effective means to model fracture problems. The DE model comprises the DE connective model and DE contact model, where the former is used for the representation of isotropic solids before cracks initiate, while the latter is employed to represent particulate materials after cracks propagate. In this paper, a DE particle-based cohesive crack model is developed to model the mixed-mode fracture process of brittle materials, aiming to simulate the material transition from a solid phase to a particulate phase. Because of the particle characteristics of the DE connective model, the cohesive crack model is constructed at inter-particle bonds in the connective stage of the model at a microscale. A potential formulation is adopted by the cohesive zone method, and a linear softening relation is employed by the traction–separation law upon fracture initiation. This particle-based cohesive crack model bridges the microscopic gap between the connective model and the contact model and, thus, is suitable to describe the material separation process from solids to particulates. The proposed model is validated by a number of standard fracture tests, and numerical results are found to be in good agreement with the analytical solutions. A notched concrete beam subjected to an impact loading is modeled, and the impact force obtained from the numerical modeling agrees better with the experimental result than that obtained from the finite element method.

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A Godunov‐type discrete element model for elastic‐viscoplastic continuum impact problems

Liu

Zhang

et al. 2021

Numerical Meth Engineering

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The discrete element model (DEM) has attractive advantages in expressing multiple cracks propagation problem in continuum, but the description of material plastic characteristics by current DEM is restricted by the connection model, which is the core procedure in DEM modeling process. A Godunov-type continuum-based DEM model is proposed to solve the dynamic response of materials under high-speed impact, in which there is a state transition of material model from continuous to discontinuous. In this article, under the framework of DEM, the contact discontinuity between adjacent elements is analyzed with the Godunov method, and a connection model derived from the physical process is established. Firstly, the numerical solution of the Riemann problem, which is equivalent to the plane wave collision operator, is solved by an iterative method, and an explicit time-marching integral format for the dynamic impact problem in elastic-viscoplastic materials is derived. Then, the numerical model is validated by comparing the calculation results with theoretical results, using a wave propagation example in plate. In addition, the capacity of simulating material property discontinuity and multiple cracks are validated by cases of stress wave transmission and reflection at the materials interface and the cracks capture in Kalthoff dynamic shear test, respectively.

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New Discrete Element Models for Three-Dimensional Impact Problems

Cited by 12 publications

References 6 publications

Mathematical Modeling of Stray Capacitance for Planar Coil at Megahertz Frequency

Mathematical Modeling of Stray Capacitance for Planar Coil at Megahertz Frequency

A Particle-Based Cohesive Crack Model for Brittle Fracture Problems

A Godunov‐type discrete element model for elastic‐viscoplastic continuum impact problems

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