A static discrete element method with discontinuous deformation analysis

2019 ◽  
Vol 120 (7) ◽  
pp. 918-935 ◽  
Author(s):  
Jingjing Meng ◽  
Jinsong Huang ◽  
Hang Lin ◽  
Jan Laue ◽  
Kaihui Li
2014 ◽  
Vol 644-650 ◽  
pp. 1539-1542 ◽  
Author(s):  
Yong Zheng Ma ◽  
Ke Jian Cai ◽  
Zhan Tao Li ◽  
Jun Li

A new enhanced Discrete Element Method (EDEM) for modeling the system composed of cracked solids is developed by coupling the traditional Discontinuous Deformation Analysis method (DDA, a kind of implicit version of DEM) with Moving Least-Squares (MLS) meshfree approximation functions. Tracing crack growth inside fracturing blocks and other related capabilities are available in the postprocessing procedure at each iteration step. Some numerical examples are provided to verify this method, and it is prospective to solve stability problems of the slope with non-through joints and other fracture mechanics problems in a new way.


2007 ◽  
Vol 353-358 ◽  
pp. 2973-2976 ◽  
Author(s):  
Yu Yong Jiao ◽  
Xiu Li Zhang ◽  
Shui Lin Wang ◽  
Huo Zhen Wu

This study is to present a numerical investigation on fragmentation and perforation of concrete slab by hard projectile using discrete particle approaches. Discrete Element Method (DEM) and Discontinuous Deformation Analysis (DDA), the two representative discrete particle approaches, are employed to simulate a normal perforation of concrete slab by a hard ogival-nose shaped projectile, and the phenomena of spalling, plugging and scabbing are reproduced.


2017 ◽  
Vol 34 (3) ◽  
pp. 832-851 ◽  
Author(s):  
Guillermo Gonzalo Schiava D'Albano ◽  
Tomas Lukas ◽  
Fang Su ◽  
Theodosios Korakianitis ◽  
Ante Munjiza

Purpose Contact interaction and contact detection (CD) remain key components of any discontinua simulations. The methods of discontinua include combined finite-discrete element method (FDEM), discrete element method, molecular dynamics, etc. In recent years, a number of CD algorithms have been developed, such as Munjiza–Rougier (MR), Munjiza–Rougier–Schiava (MR-S), Munjiza-No Binary Search (NBS), Balanced Binary Tree Schiava (BBTS), 3D Discontinuous Deformation Analysis and many others. This work aims to conduct a numerical comparison of certain algorithms often used in FDEM for bodies of the same size. These include MR, MR-S, NBS and BBTS algorithms. Design/methodology/approach Computational simulations were used in this work. Findings In discrete element simulations where particles are introduced randomly or in which the relative position between particles is constantly changing, the MR and MR-S algorithms present an advantage in terms of CD times. Originality/value This paper presents a detailed comparison between CD algorithms. The comparisons are performed for problem cases with different lattices and distributions of particles in discrete element simulations. The comparison includes algorithms that have not been evaluated between them. Also, two new algorithms are presented in the paper, MR-S and BBTS.


2009 ◽  
Vol 16-19 ◽  
pp. 1283-1288
Author(s):  
Yong Ye ◽  
Yuan Li ◽  
Xi Peng Xu

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.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1252
Author(s):  
Hongming Luo ◽  
Guanhua Sun ◽  
Lipeng Liu ◽  
Wei Jiang

To avoid disadvantages caused by rotational degrees of freedom in the original Discontinuous Deformation Analysis (DDA), a new block displacement mode is defined within a time step, where displacements of all the block vertices are taken as the degrees of freedom. An individual virtual element space V1(Ω) is defined for a block to illustrate displacement of the block using the Virtual Element Method (VEM). Based on VEM theory, the total potential energy of the block system in DDA is formulated and minimized to obtain the global equilibrium equations. At the end of a time step, the vertex coordinates are updated by adding their incremental displacement to their previous coordinates. In the new method, no explicit expression for the displacement u is required, and all numerical integrations can be easily computed. Four numerical examples originally designed by Shi are analyzed, verifying the effectiveness and precision of the proposed method.


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