Dynamic analysis of autonomous risk avoidance of amphibious floating bridge based on discrete element method and physical engine

In this paper, based on an intelligent floating bridge, by using discrete element methods and physical engines, under the action of certain missile repulsion fields, the force process and motion path in the process of autonomous evasion of missiles are studied. Firstly, the static simulation of missile repulsion fields is carried out by using the polynomial least square surface fitting method. According to the strength of repulsion field at different times and the extrusion force between the pontoons, the kinematic equation of the pontoon is established. The equation is discretised by using a discrete element method, and the kinematic equation is obtained according to the time iteration. Then, motion analysis is carried out by using a physical engine on the basis of equation Analysis. Finally, the position parameters before and after the self-evasion missile of the floating bridge are calculated, and the simulation program is written in MATLAB. The dynamic simulation experiment of the whole evasion missile process is carried out, and the results are satisfactory.

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Experimental and Numerical Study of Railway Ballast Compactness during Tamping Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.690-693.2730 ◽

2013 ◽

Vol 690-693 ◽

pp. 2730-2733

Author(s):

Tao Yong Zhou ◽

Bin Hu ◽

Bo Yan ◽

Jun Feng Sun

Keyword(s):

Discrete Element Method ◽

Numerical Study ◽

Discrete Element ◽

Railway Track ◽

Analysis Model ◽

Railway Ballast ◽

Element Analysis ◽

Before And After ◽

Filling Method ◽

Element Method

Railway ballast tamping operations is employed in order to restore the geometry of railway track distorted by train traffics. The main goal is to compact the stone ballast under the sleepers supporting the railway squeezing and vibrations. The ballast compactness is the most direct index for evaluating the effect of tamping operation. This paper presents an experimental method used to detect the railway ballast compactness before and after tamping operation based on water-filling method, and creates a discrete element analysis model of railway ballast which analyzes the change of ballast compactness before and after tamping operation based on discrete element method. The simulation results are very similar with experimental results, which verify that the discrete element method is an effective method to evaluate the change of railway ballast compactness during tamping process.

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The Study Summery of Segregation Characters for Asphalt Mixture Based on Discrete Element Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1065-1069.818 ◽

2014 ◽

Vol 1065-1069 ◽

pp. 818-821

Author(s):

Jing Yan Li

Keyword(s):

Numerical Simulation ◽

Discrete Element Method ◽

Asphalt Mixture ◽

Discrete Element ◽

Relevant Theory ◽

Advantages And Disadvantages ◽

Discrete Element Methods ◽

Theory Research ◽

Element Method ◽

At Home

This paper summarizes the characteristics of the relevant theory research of asphalt mixture segregation at home and abroad in recent years, the use of discrete element methods, by summing up the results of different studies scholars, analysis of discrete element method to simulate Evaluation of asphalt mixture segregation as well as its advantages and disadvantages, numerical simulation to explore the direction of development.

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Application of Discrete Element Methods to the Problem of Rock Bumps

Acta Polytechnica ◽

10.14311/378 ◽

2002 ◽

Vol 42 (4) ◽

Author(s):

P. P. Procházka ◽

M. G. Kugblenu

Keyword(s):

Discrete Element Method ◽

Granular Media ◽

Dynamic Equilibrium ◽

Discrete Element ◽

Particle Flow ◽

Particle Flow Code ◽

Classical Particle ◽

Discrete Element Methods ◽

Scaled Models ◽

Element Method

This paper is a continuation of a previous paper by the authors. Applications of two discrete element methods (DEM) to several fields of geotechnics are discussed. The free hexagon element method is considered a powerful discrete element method, and is widely used in mechanics of granular media. It substitutes the methods for solving continuum problems. In order to complete the study, other discrete element methods are discussed. The second method starts with the classical particle flow code (PFC, which uses dynamic equilibrium), but we apply static equilibrium in our case. The second method is called the static particle flow code (SPFC). The numerical experiences and comparison with experimental results from scaled models are discussed.

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Modeling of the fragmentation by Discrete Element Method

DYMAT 2009 - 9th International Conferences on the Mechanical and Physical Behaviour of Materials under Dynamic Loading ◽

10.1051/dymat/2009215 ◽

2009 ◽

Author(s):

C. Mariotti ◽

V. Michaut ◽

J. F. Molinari

Keyword(s):

Discrete Element Method ◽

Discrete Element ◽

Element Method

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Discrete element method to model cracking for two layer systems

TAPPI Journal ◽

10.32964/tj18.2.101 ◽

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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