Discrete element analysis of breakage of irregularly shaped railway ballast

2014 ◽  
Vol 10 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Ying Yan ◽  
Jinfeng Zhao ◽  
Shunying Ji
2014 ◽  
Vol 988 ◽  
pp. 315-318
Author(s):  
Bo Yan ◽  
Bin Hu ◽  
Ya Yu Huang ◽  
Tao Yong Zhou

Railway ballast dynamic stability operations is an important work in the line maintenance and repair operations, the selection of dynamic parameter is usually dependent on field trials and practical experience, for lack of theoretical basis. This paper creates discrete element analysis model of railway ballast using the discrete element method, the numerical simulations are carried out to study the lateral ballast resistance during dynamic stability process. We focus on the influence of vibration frequency during dynamic stability process; an optimal vibration frequency of the simulation analysis is obtained and compared with the recommended vibration frequency of a product of a China Railway Large Maintenance Machinery Company, it is found that the two vibration frequencies are basically consistent. This result verifies the correct validity of the discrete element analysis model of railway ballast during dynamic stability process.


2013 ◽  
Vol 690-693 ◽  
pp. 2730-2733
Author(s):  
Tao Yong Zhou ◽  
Bin Hu ◽  
Bo Yan ◽  
Jun Feng Sun

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.


2016 ◽  
Vol 143 ◽  
pp. 1068-1076 ◽  
Author(s):  
Enad Mahmoud ◽  
A.T. Papagiannakis ◽  
David Renteria

2012 ◽  
Vol 233 ◽  
pp. 224-227 ◽  
Author(s):  
Tao Yong Zhou ◽  
Bin Hu ◽  
Xue Jun Wang ◽  
Bo Yan

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.


2013 ◽  
Vol 7 (1) ◽  
pp. 103-109 ◽  
Author(s):  
Taoyong Zhou ◽  
Bin Hu ◽  
Junfeng Sun ◽  
Zhongtian Liu

Railway ballast tamping operation is employed in order to restore the geometry of railway track distorted by train traffics. In this paper, based on analysis of tamping principle, the discrete element analysis model of railway ballast is created using the discrete element method, numerical simulations are performed to study the change of railway ballast compactness during tamping process. This paper presents the motion trend of stone ballasts as the change trend of railway ballast compactness in qualitative analysis, and the distance between stone ballast and sleeper as the change index of railway ballast compactness in quantitative analysis. By comparing simulation data of different vibration frequencies, an optimal vibration frequency is obtained. The simulation results accord with the actual industrial tamping operation, which verifies that the discrete element method is an effective method to evaluate the change of railway ballast compactness during tamping process.


2012 ◽  
Vol 190-191 ◽  
pp. 369-372
Author(s):  
Tao Yong Zhou ◽  
Bin Hu ◽  
Xue Jun Wang ◽  
Bo Yan

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 lack of theoretical basis. 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 vibration frequency during tamping process; an optimal vibration frequency of the simulation analysis is obtained and compared with the recommended vibration frequency of Plasser & Theurer Company, it is found that the two vibration frequencies accord. This result verifies the correct validity of the discrete element analysis model of railway ballast during tamping process.


2014 ◽  
Vol 919-921 ◽  
pp. 1124-1127
Author(s):  
Tao Yong Zhou ◽  
Bin Hu ◽  
Xue Yu Zhao ◽  
Bo Yan

Tamping operation is an important part of railway maintenance work. The porosity of railway ballast is an important maintenance quality evaluation index during tamping process. In this paper, based on the discrete characteristics of railway ballast, the discrete element analysis model of railway ballast is created using the discrete element method, numerical simulations are performed to study the evolution of porosity of railway ballast under sleeper during tamping process. This paper focuses on the influence of vibration frequency of tamping tines during tamping process; an optimal vibration frequency is obtained from the simulation and compared with the actual vibration frequency recommended by China Railway Large Maintenance Machinery Co., Ltd. Kunming, it is found that the two vibration frequency is consistent. This result verifies that the discrete element method is an effective method to study the evolution of porosity of railway ballast during tamping process.


2013 ◽  
Vol 690-693 ◽  
pp. 2726-2729 ◽  
Author(s):  
Tao Yong Zhou ◽  
Bin Hu ◽  
Bo Yan ◽  
Ping Xu

Railway ballast tamping operations is employed in order to restore the geometry of railway track distorted by train traffics. The selection of tamping parameter is usually dependent on field trials and practical experience, for lack of theoretical basis. This paper creates discrete element analysis model of railway ballast using the discrete element method, the numerical simulations are carried out to study the mesomechanics of railway ballast during tamping process. We focus on the change of railway ballast compactness and stone ballast interaction force during tamping process. The present study can be helpful for the analysis of the internal mechanism of ballast compaction during tamping process.


Author(s):  
Alfredo Gay Neto ◽  
Peter Wriggers

AbstractWe present a version of the Discrete Element Method considering the particles as rigid polyhedra. The Principle of Virtual Work is employed as basis for a multibody dynamics model. Each particle surface is split into sub-regions, which are tracked for contact with other sub-regions of neighboring particles. Contact interactions are modeled pointwise, considering vertex-face, edge-edge, vertex-edge and vertex-vertex interactions. General polyhedra with triangular faces are considered as particles, permitting multiple pointwise interactions which are automatically detected along the model evolution. We propose a combined interface law composed of a penalty and a barrier approach, to fulfill the contact constraints. Numerical examples demonstrate that the model can handle normal and frictional contact effects in a robust manner. These include simulations of convex and non-convex particles, showing the potential of applicability to materials with complex shaped particles such as sand and railway ballast.


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