A Mini-Network Simulation Approach to Investigate the Capacity and Safety Aspects of National Rail Network

2021 ◽  
Author(s):  
Hamed Pouryousef ◽  
Monique Stewart ◽  
Som P. Singh ◽  
Anand Prabhakaran
Keyword(s):  
High Speed ◽  
Network Simulation ◽  
Network Capacity ◽  
Impact Factors ◽  
Simulation Approach ◽  
Analytical Technique ◽  
Rail Network ◽  
Advanced Technologies ◽  
The Impact ◽  
The U.S

Abstract Over the last decades there have been major technology advancements in the railroad industry to improve the operational safety as well as performance of freight trains in shared-use corridors. This study was focused on developing a methodology that allows evaluation of the impact of such advanced technologies over the safety and capacity aspects of the U.S. rail network using a benchmark mini-network simulation approach. A hypothetical mini-network of 5,000 miles of track with characteristics typical of the North American rail network was developed. Two hundred thirty two (232) daily trains, including a mix of intercity passenger, commuter, High Speed Rail and 78 freight trains, were used to simulate the traffic flow. Several network capacity and safety related parameters; network delay, network velocity, track utilization level, number of stops at stations, number of braking for route reservations, and number of stops at signals were analyzed in this study. The results of the benchmark network simulations were then extended to the U.S. rail network, using an analytical technique with assumptions for important parameters and impact factors such as total route miles, freight train-miles, number of sidings/yards, congestion level and age of fleets. The results indicate that the methodology is able to quantify the improvement in network capacity and safety features that can be obtained when advanced technologies are deployed on freight trains.

scholarly journals Examining partial proportional odds model in analyzing severity of high-speed railway accident

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jing Wang ◽  
Yinghan Wang ◽  
Yichuan Peng ◽  
Jian John Lu
Keyword(s):  
High Speed ◽  
Proportional Odds Model ◽  
Impact Factors ◽  
Proportional Odds ◽  
High Speed Railway ◽  
Severity Level ◽  
Content Type ◽  
Factors Affecting ◽  
Partial Proportional Odds Model ◽  
The Impact

Purpose The operation safety of the high-speed railway has been widely concerned. Due to the joint influence of the environment, equipment, personnel and other factors, accidents are inevitable in the operation process. However, few studies focused on identifying contributing factors affecting the severity of high-speed railway accidents because of the difficulty in obtaining field data. This study aims to investigate the impact factors affecting the severity of the general high-speed railway. Design/methodology/approach A total of 14 potential factors were examined from 475 data. The severity level is categorized into four levels by delay time and the number of subsequent trains that are affected by the accident. The partial proportional odds model was constructed to relax the constraint of the parallel line assumption. Findings The results show that 10 factors are found to significantly affect accident severity. Moreover, the factors including automation train protection (ATP) system fault, platform screen door and train door fault, traction converter fault and railway clearance intrusion by objects have an effect on reducing the severity level. On the contrary, the accidents caused by objects hanging on the catenary, pantograph fault, passenger misconducting or sudden illness, personnel intrusion of railway clearance, driving on heavy rain or snow and train collision against objects tend to be more severe. Originality/value The research results are very useful for mitigating the consequences of high-speed rail accidents.

scholarly journals Nonlinear Dynamic Analysis and Chaos Prediction of Grinding Motorized Spindle System

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Weitao Jia ◽  
Feng Gao ◽  
Yan Li ◽  
Wenwu Wu ◽  
Zhongwei Li
Keyword(s):  
Nonlinear Dynamic ◽  
High Speed ◽  
Chaotic Behavior ◽  
Nonlinear Dynamic Analysis ◽  
Phase Portraits ◽  
Impact Factors ◽  
Nonlinear Dynamic Model ◽  
Motorized Spindle ◽  
Spindle System ◽  
The Impact

The paper determines the impact factors of dynamics of a motorized spindle rotor system due to high speed: centrifugal force and bearing stiffness softening. A nonlinear dynamic model of the grinding motorized spindle system considering the above impact factors is constructed. Through system simulation including phase portraits and Poincaré map, the periodic behavior and chaotic behavior of the nonlinear grinding motorized spindle system are revealed. The threshold curve of chaos motion is obtained through the Melnikov method. The conclusion can provide a theoretical basis for researching deeply the dynamic behaviors of the grinding motorized spindle system.

Dynamic precision analysis and experimental verification of high-speed precision punch press

2016 ◽  
Vol 230 (20) ◽  
pp. 3655-3662 ◽  
Author(s):  
Fengfeng Hu ◽  
Yu Sun ◽  
Binbin Peng
Keyword(s):  
Elastic Wave ◽  
Dynamic Model ◽  
High Speed ◽  
Impact Factors ◽  
Superposition Method ◽  
Bottom Dead Center ◽  
Dynamic Precision ◽  
Modal Superposition Method ◽  
The Impact ◽  
Punch Press

In order to investigate the impact factors and their affection on high-speed precision multilink punch press (MPP), the dynamic model with different joint clearance was established, and the influence of different clearance and speed on the dynamic positional repeatability of bottom dead center (BDC) was analyzed. The elastic dynamic model of high-speed MPP was established, the affection of the elastic deformation and elastic wave on the positional repeatability of the BDC were presented by using modal superposition method to solve dynamic equation. Meanwhile, experiments on the dynamic repeatability of the BDC of the punch during working were completed. At last, the comparison of the experimental results with the analyzed results was given, and based on which, it can be concluded that the clearance, elastic wave and deformation are the key factors of the dynamic repeatability precision of the BDC.

Measuring the Impact of Advanced Technologies and Reorganization on Human Performance in a Combat Information Center

2000 ◽  
Vol 44 (37) ◽  
pp. 642-645 ◽  
Author(s):  
Jared T. Freeman ◽  
Gwendolyn E. Campbell ◽  
Greg Hildebrand
Keyword(s):  
Human Behavior ◽  
Team Performance ◽  
Preliminary Data ◽  
Human Performance ◽  
Novel Technology ◽  
Advanced Technologies ◽  
Information Center ◽  
And Control ◽  
The Impact ◽  
The U.S

Systematically evaluating the impact of novel technology and organizational structure on team performance is a complex, multidimensional task. We define several of these dimensions that are of particular interest in the development of new command and control teams and technologies for the U.S. Navy. In addition, we describe an approach to stimulating and measuring human behavior on these dimensions, and an experiment in which this approach is applied. Preliminary data are presented.

scholarly journals Speed Effects on Inherent Rotating Frequency of Motorized Spindle System

2011 ◽  
Vol 2-3 ◽  
pp. 900-905 ◽  
Author(s):  
Bo Wang ◽  
Wei Sun ◽  
Kun Peng Xu ◽  
Bang Сhuan Wen
Keyword(s):  
Centrifugal Force ◽  
High Speed ◽  
Impact Factors ◽  
Motorized Spindle ◽  
Spindle System ◽  
High Speeds ◽  
Radial Stiffness ◽  
Bearing Stiffness ◽  
Coupling Factors ◽  
The Impact

The paper determines the impact factors of high-speed spindle system including the centrifugal force, gyroscopic moments and the bearing stiffness softening, etc, then builds the general spindle-bearing FEM considering high speeds. Taking a motorized spindle as example, the effect of centrifugal force, gyroscopic effect, the radial stiffness and the coupling factors are analyzed qualitatively and quantitatively. Finally the research shows the variations of bearing radial stiffness, centrifugal force and gyroscopic moments have a significant effect on dynamics of spindle system in high speeds, while modeling the high speed spindle system, above factors must be considered.

scholarly journals Numerical analysis of beam rail bridges - impact factors in the vertical deflection

2017 ◽  
Vol 2017 (9) ◽  
pp. 11-17 ◽  
Author(s):  
Monika Podwórna
Keyword(s):  
High Speed ◽  
Equations Of Motion ◽  
Impact Factors ◽  
Vertical Deflection ◽  
Lagrange Equations ◽  
High Speeds ◽  
Rail Vehicles ◽  
Non Linear ◽  
Random Track Irregularities ◽  
The Impact

The impact factors in the vertical deflection obtained in dynamic analysis of BTT systems - bridged / track structure / high speed train (BTT) - are discussed. The BTT system is one of 5 bridges spanning from 15 m to 27 m, modelled as simply supported beams loaded by ICE-3 trains traveling at high speeds. The two-dimensional, physically non-linear BTT model includes: viscoelastic suspension of rail vehicles on two independent axle bogies and non-linear one-sided wheel-rail contact springs according to Hertz theory, access zones for composite construction. The BTT system was divided into subsystems loaded with vertical interactions transmitted by elastic or viscoelastic and physically linear or nonlinear constraints. Using Lagrange equations and internal aggregation of subsystems, discretised according to the finite element method, matrix equations of motion of the subsystems were obtained, with explicit linear left sides and nonlinear implicit right sides, which were integrated numerically using the Newmark method with parameters βN=1/4, γN=1/2. The analysis focus on the effect of random track irregularities on the dynamic response of BTT systems.

A Finite Element Methodology to Study Soil–Structure Interaction in High-Speed Railway Bridges

2018 ◽  
Vol 13 (3) ◽  
Author(s):  
Antonio Martínez-De la Concha ◽  
Héctor Cifuentes ◽  
Fernando Medina
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Soil Structure ◽  
Soil Structure Interaction ◽  
Sensitivity Analyses ◽  
Impact Factors ◽  
Structure Interaction ◽  
Finite Element Software ◽  
High Speed Trains ◽  
The Impact

This paper analyzes the dynamic soil–structure interaction (SSI) of a railway bridge under the load transmitted by high-speed trains using the finite element method (FEM). In this type of bridges, the correct analysis of SSI requires proper modeling of the soil; however, this task is one of the most difficult to achieve with the FEM method. In this study, we explored the influence of SSI on the dynamic properties of the structure and the structure's response to high-speed train traffic using commercial finite element software with direct integration and modal superposition methods. High-speed trains are characterized by the high-speed load model (HSLM) in the Eurocode. We performed sensitivity analyses of the influence of several parameters on the model, such as the size and stiffness of the discretized soil, mesh size, and the influence of the dynamic behavior of the excitation. Based on the results, we make some important and reliable recommendations for building an efficient and simple model that includes SSI. We conducted a dynamic analysis of a full model of a general multispan bridge including the piers, abutments, and soil and identified the impact factors that affected the design of the bridge. The analysis revealed that the methodology we propose allows for a more accurate determination of the dynamic effects of the passage of a train over the bridge, compared to the simpler and more widely used analysis of a directly supported isolated deck, which tends to overestimate the impact factors.

High-speed rail network in China: the contribution of fast trains to regional tourism and economic development

2019 ◽  
Vol 75 (2) ◽  
pp. 414-432
Author(s):  
Mingwei Li ◽  
Juan Chen
Keyword(s):  
High Speed ◽  
Regional Economy ◽  
Comparison Method ◽  
High Speed Rail ◽  
High Speed Railway ◽  
Content Type ◽  
Rail Network ◽  
Regional Tourism ◽  
City Tourism ◽  
The Impact

Purpose The high-speed rail network can lead to the transformation of the tourism industry, as well as the regional economy. In the present study, a reasonable method was developed to assess the contributions of high-speed rail network to the development of tourism and economy in a Chinese region known as the “1 + 8” city tourism circle. Design/methodology/approach The method proposed here combines not only tourism revenue but also regional economy in a MGM (1, n) gray model, and it studies the tourist and economic output of this tourism circle before and after the high-speed rail network’s construction using an advanced “with and without comparison” method. Findings By using this method, the accuracy of the prediction of the contribution rate of high-speed rail network is improved. We found that in the “1 + 8” city tourism circle, the high-speed rail network positively contributes to increase of the tourism arrival and tourism revenue. Furthermore, regional economy significantly grows under the impact of the high-speed rail network. Research limitations/implications The “1 + 8” city tourism circle is studied as a closed system in this paper, and the authors focus on the economic associations between the cities in the circle by ignoring the impact from outside this circle. This treatment means, simplifies and enables the feasibility of this study, but it virtually leads to the deviation of outcomes between this study and the practical. Practical implications For theoretical values, by studying a normal Chinese inland region, this study reconfirmed the positive impact of high-speed railway empirically. In the meantime, this study developed an improved method by introducing gray theory models to “with and without comparison” method to calculate the contribution of high-speed railway to the regional tourism and economy development. Such method simultaneously incorporates the indexes of regional tourism income and regional GDP simultaneously. It is direct and convenient as it can achieve accuracy requirements using only a small amount of data, and it reconciles more with reality by considering the interaction of the outcomes of tourism and economy. Social implications For practical values, using the proposed method, a direct and convenient calculation of the contributions of high-speed railway to many other regions can be achieved if the data of the outcomes of tourism and economy can be obtained. In such a way, the regions that really need high-speed railway to stimulate their development can be distinguished from regions whose high-speed railway is under blind construction. Thus, the government may take actions to reassess some uneconomic high-speed railway projects without discouraging the construction of high-speed railway in other regions. The authors believe that this is important not only for China but also for many other countries with high-speed railway projects. Originality/value This study develops a reasonable method of assessing the contribution of high-speed rail to regional tourism and economic development. Using this method, this study confirmed that high-speed rail indeed positively impacts the regional development.

Analysis of the Forces on a Nuclear Fuel Transport Flask in an Impact by a Train

1987 ◽  
Vol 201 (1) ◽  
pp. 55-68 ◽  
Author(s):  
J C Miles ◽  
T C K Molyneaux ◽  
H J Dowler
Keyword(s):  
Mathematical Modelling ◽  
High Speed ◽  
High Speed Train ◽  
Energy Agency ◽  
The Public ◽  
Rail Network ◽  
Analytical Work ◽  
The Impact ◽  
Public Demonstration ◽  
Primary Impact

The majority of fuel transport flask movements is on the public rail network and there has been concern over the possible consequences in the unlikely event of an accident involving a flask. To allay these concerns the Central Electricity Generating Board (CEGB) embarked on a programme of research into the behaviour of flasks in accidents culminating in the public demonstration of a train imapct in July 1984. The train crash demonstration was preceded by extensive analytical work directed at estimating the forces, effects and resulting motions of the primary impact. The mathematical modelling and analyses are described, with an earlier study of a high-speed train (HST) impact, and subsequent comparisons between the predictive estimates and the results of the demonstration. The impact effects expected and found are given in detail, with conclusions on the success of the estimating work and the relative severity of the IAEA (International Atomic Energy Agency) 9 m drop test compared with the train crash.

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