Dynamic Behavior Analysis of High-Speed Railway Ballast under Moving Vehicle Loads Using Discrete Element Method

2017 ◽  
Vol 17 (7) ◽  
pp. 04016157 ◽  
Author(s):  
Xu Zhang ◽  
Chunfa Zhao ◽  
Wanming Zhai
Keyword(s):  
Discrete Element Method ◽  
Behavior Analysis ◽  
Dynamic Behavior ◽  
High Speed ◽  
Discrete Element ◽  
Railway Ballast ◽  
High Speed Railway ◽  
Moving Vehicle ◽  
Vehicle Loads ◽  
Element Method

Study on the DEM Simulation of the Granular Railway Ballast Bed Tamping

2012 ◽  
Vol 524-527 ◽  
pp. 3256-3259 ◽  
Author(s):  
Xue Jun Wang ◽  
Yi Lin Chi ◽  
Wei Li ◽  
Tao Yong Zhou
Keyword(s):  
Discrete Element Method ◽  
High Speed ◽  
Flow Simulation ◽  
Discrete Element ◽  
Random Force ◽  
Railway Ballast ◽  
Main Work ◽  
Coupling Dynamic ◽  
Significant Measure ◽  
Element Method

Abstract. Since the action of high speed train and the repeated heavy loadings, the degradation and deformation that do not restore is produced in the granular railway ballast. Tamping action is an effective method that is being used to recover the elastic of the track. In order to examine the displacement and vibration characteristics of the railway ballast particles while tamped, in this article, main work is being used to establish a coupling discrete particle flow simulation model of the railway ballast and tamping tines in EDEM with the discrete element method. The two main contents are concerned in this paper. The first is to research the modeling method of ballast particles in the software EDEM. The second is to establish a rigid-flexible coupling dynamic model of railway ballast tamping system, and according to this model, the dynamic response of the granular particles under tamping load is calculated. From a numerical simulation, we can find the effect of ballast’s vibration characteristic is related to the shape of particles in significant measure. The research shows the discrete element method is an effective method for solving the vibration problem of railway ballast of random force vibration.

Experimental and Numerical Study of Railway Ballast Compactness during Tamping Process

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.

scholarly journals A Numerical Study of Railway Ballast Subjected to Direct Shearing Using the Discrete Element Method

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Hongyi Zhao ◽  
Jing Chen
Keyword(s):  
Discrete Element Method ◽  
Mechanical Performance ◽  
Numerical Study ◽  
Discrete Element ◽  
Contact Forces ◽  
Angle Of Repose ◽  
Particle Rotation ◽  
Railway Ballast ◽  
Depth Analysis ◽  
Element Method

Railway ballast is a coarse granular material used to carry train loads and provide drainage for the rail tracks. This study presents numerical explorations of the mechanical performance of ballast aggregates subjected to direct shear tests. The discrete element method (DEM) was used to investigate the microscopic characteristics of ballast aggregates during shearing while considering contact distribution, particle rotation, and particle displacement. By testing the angle of repose of ballast aggregates, the parameters for the DEM contact model could be calibrated. Four specimens were prepared and then subjected to different normal pressures. The results show that the contact between ballast particles intensifies in terms of the amount and magnitude as the normal pressure increases. A Fourier analysis was applied to investigate the anisotropy of contact normal and the contact forces for ballast aggregates at different shearing phases. The rotational and translational movements of ballast particles were investigated, and this investigation revealed that particle rotation gradually increased as the shearing propagated. Four regions in the aggregates were identified according to the translational pattern of ballast particles. The results of this research provide an in-depth analysis of microscopic characteristics from a particulate scale.

Drag reduction and wear resistance mechanisms of a bionic shovel by discrete element method simulation

SIMULATION ◽  
2018 ◽  
Vol 95 (3) ◽  
pp. 231-239 ◽  
Author(s):  
Rui Zhang ◽  
Dianlei Han ◽  
Yuan He ◽  
Haijin Wan ◽  
Songsong Ma ◽  
...  
Keyword(s):  
Discrete Element Method ◽  
Drag Reduction ◽  
High Speed ◽  
Three Dimensional ◽  
Discrete Element ◽  
Resistance Mechanisms ◽  
Fatigue Wear ◽  
Soil Particles ◽  
The Common ◽  
Element Method

The ostrich has a steady and enduring high-speed running ability. Toenails are one key part of ostrich feet and their unique morphology is crucial in insertion into sand and for traction provision. In this study, information of bionic curves was extracted through studying the toenail structure and morphology, and three-dimensional reconstruction of toenails by reverse engineering. Based on the principle of bionic engineering, a bionic shovel was designed by optimizing the traditional shovel. A shovel–soil interaction mechanical model was established via the discrete element method. The insertion into soil processes of the bionic shovel and the common plate were simulated. The dynamic mesoscopic mechanical behaviors of soil particles around the shovel surface, the contact force field, and the velocity field, as well as the forces acting on the shovel surface were analyzed. The bionic shovel outperformed the common plate in insertion. The main reason for drag reduction in the bionic shovel was the inner concave bending surface, along which the soil particles climbed, and the particle movement trend was consistent. Simulations showed stress concentrated at the tip of the shovel, which facilitated the production of fatigue wear. Therefore, the tip needs to be considered firstly during bionic shovel design in the future.

Discrete Element Method Analysis of Mechanical Properties of Railway Ballast during Tamping Process under Different Amplitude

2012 ◽  
Vol 233 ◽  
pp. 224-227 ◽  
Author(s):  
Tao Yong Zhou ◽  
Bin Hu ◽  
Xue Jun Wang ◽  
Bo Yan
Keyword(s):  
Mechanical Properties ◽  
Discrete Element Method ◽  
Simulation Analysis ◽  
Discrete Element ◽  
Practical Experience ◽  
Field Trials ◽  
Analysis Model ◽  
Railway Ballast ◽  
Element Analysis ◽  
Element Method

Railway ballast tamping operations is an important work in the line maintenance and repair operations, the selection of tamping parameter is usually dependent on field trials and practical experience, for the mechanical properties of railway ballast is difficult to measure and describe. This paper creates discrete element analysis model of railway ballast using the discrete element method, the numerical simulations are carried out to study the mechanical properties of railway ballast during tamping process. We focus on the influence of amplitude during tamping process; an optimal amplitude of the simulation analysis is obtained and compared with the recommended amplitude of Plasser & Theurer Company, it is found that the two amplitudes accord. This result verifies the correct validity of the discrete element analysis model of railway ballast during tamping process.

Discrete element method of improved performance of railway ballast bed using elastic sleeper

2015 ◽  
Vol 22 (8) ◽  
pp. 3223-3231 ◽  
Author(s):  
Liang Gao ◽  
Qi Luo ◽  
Yang Xu ◽  
Guo-qing Jing ◽  
Han-ke Jiang
Keyword(s):  
Discrete Element Method ◽  
Discrete Element ◽  
Railway Ballast ◽  
Improved Performance ◽  
Element Method
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