A new railway design is allowing the latest highspeed rail line to pass through national natural reserves while causing only minor disturbance to local wildlife.The Xi’an-Chengdu high-speed rail,which opened on Wedne...A new railway design is allowing the latest highspeed rail line to pass through national natural reserves while causing only minor disturbance to local wildlife.The Xi’an-Chengdu high-speed rail,which opened on Wednesday,is the first bullet train to cut though the Qinling Mountains,in Shanxi province,which are home to many rare wild animals including the giant panda,golden monkey,crested ibis and golden takin.展开更多
Rail wear is one of the main reasons for reducing the service life of high-speed railway turnouts in China. The rail wear characteristics of high-speed railway turnouts are influenced by a large number of input parame...Rail wear is one of the main reasons for reducing the service life of high-speed railway turnouts in China. The rail wear characteristics of high-speed railway turnouts are influenced by a large number of input parameters of the complex train-turnout system. To reproduce the actual operation conditions of railway turnouts, random distributions of these inputs need to be considered in rail wear simulation. For a given nominal layout of the high-speed railway turnout, 19 input parameters for rail wear simulation in high-speed railway turnouts are investigated based on orthogonal design of experiment. Three dynamic responses(wheel-rail friction work, normal contact force and size of contact patch) are defined as observed values and the significant factors(direction of passage, axle load, running speed, friction coefficient, and wheel and rail profiles) are determined by two unreplicated saturated factorial design methods, including the half-normal probability plot method and Dong 93 method. As part of the associated rail wear simulation, the influence of the wear models and the local elastic deformation on the rail wear was separately investigated. The calculation results for the wear models are quite different, especially for large creep mode. The local elastic deformation has a large effect on the sliding speed and rail wear and needs to be considered in the rail wear simulation.展开更多
The monitoring and warning of urban rail transit is the core of operation management, and the breadth and depth of the monitoring range directly affect the quality of urban rail transit operation. For the current dome...The monitoring and warning of urban rail transit is the core of operation management, and the breadth and depth of the monitoring range directly affect the quality of urban rail transit operation. For the current domestic monitoring system, most of the critical equipments and technologies are introduced from abroad;it is diseconomy, and also causes hidden danger. Realizing the localization of monitoring and early warning system is imperative. Based on the analysis of the present situation of urban rail transit operation safety at home and abroad, the paper proposes to use integrated technology to design basic framework of monitoring and warning system of urban rail train, and puts forward the critical technologies to realize the system. Compared with the existing monitoring system, the integrated monitoring system has the characteristics of wide monitoring range, clear division of labor, centralized management, coordination and integration operation and intelligent management, and embodies the concept of people-oriented. It has scientific significance for future construction of domestic Integrated Monitoring and Early Warning System (IMEWS) of urban rail transit.展开更多
According to the study on 39 sites of rail transit Line 3 in Chongqing, the sites are classifi ed into three types: residential type, business center type, traffi c hub type in this paper. The study shows that the sit...According to the study on 39 sites of rail transit Line 3 in Chongqing, the sites are classifi ed into three types: residential type, business center type, traffi c hub type in this paper. The study shows that the sites have many problems such as discordance of land use, severity of spatial segregation, low rate of site utilization. To solve these problems, development approaches of site space resources within 1,000 m around the site area are further explored. The approaches include four aspects: characteristics of land use, functional composite, walking guide and shuttle transportation. In addition, appropriate planning and design methods are proposed.展开更多
Based on the numerical simulation analysis, structure parameters of the high pressure fuel pump and common rail as well as flow limiter are designed and the GD-1 high pressure common rail fuel injection system is self...Based on the numerical simulation analysis, structure parameters of the high pressure fuel pump and common rail as well as flow limiter are designed and the GD-1 high pressure common rail fuel injection system is self-developed. Fuel injection characteristics experiment is performed on the GD-1 system. And double-factor variance analysis is applied to investigate the influence of the rail pressure and injection pulse width on the consistency of fuel injection quantity, thus to test whether the design of structure parameters is sound accordingly. The results of experiment and test show that rail pressure and injection pulse width as well as their mutual-effect have no influence on the injection quantity consistency, which proves that the structure parameters design is successful and performance of GD-1 system is sound.展开更多
文摘A new railway design is allowing the latest highspeed rail line to pass through national natural reserves while causing only minor disturbance to local wildlife.The Xi’an-Chengdu high-speed rail,which opened on Wednesday,is the first bullet train to cut though the Qinling Mountains,in Shanxi province,which are home to many rare wild animals including the giant panda,golden monkey,crested ibis and golden takin.
基金Projects(51425804,51378439,51608459)supported by the National Natural Science Foundation of ChinaProjects(U1334203,U1234201)supported by the Key Project of the China’s High-Speed Railway United Fund+1 种基金Project(2016M590898)supported by China Postdoctoral Science FoundationProject(2014GZ0009)supported by Sichuan Provinial Science and Technology support Program,China
文摘Rail wear is one of the main reasons for reducing the service life of high-speed railway turnouts in China. The rail wear characteristics of high-speed railway turnouts are influenced by a large number of input parameters of the complex train-turnout system. To reproduce the actual operation conditions of railway turnouts, random distributions of these inputs need to be considered in rail wear simulation. For a given nominal layout of the high-speed railway turnout, 19 input parameters for rail wear simulation in high-speed railway turnouts are investigated based on orthogonal design of experiment. Three dynamic responses(wheel-rail friction work, normal contact force and size of contact patch) are defined as observed values and the significant factors(direction of passage, axle load, running speed, friction coefficient, and wheel and rail profiles) are determined by two unreplicated saturated factorial design methods, including the half-normal probability plot method and Dong 93 method. As part of the associated rail wear simulation, the influence of the wear models and the local elastic deformation on the rail wear was separately investigated. The calculation results for the wear models are quite different, especially for large creep mode. The local elastic deformation has a large effect on the sliding speed and rail wear and needs to be considered in the rail wear simulation.
文摘The monitoring and warning of urban rail transit is the core of operation management, and the breadth and depth of the monitoring range directly affect the quality of urban rail transit operation. For the current domestic monitoring system, most of the critical equipments and technologies are introduced from abroad;it is diseconomy, and also causes hidden danger. Realizing the localization of monitoring and early warning system is imperative. Based on the analysis of the present situation of urban rail transit operation safety at home and abroad, the paper proposes to use integrated technology to design basic framework of monitoring and warning system of urban rail train, and puts forward the critical technologies to realize the system. Compared with the existing monitoring system, the integrated monitoring system has the characteristics of wide monitoring range, clear division of labor, centralized management, coordination and integration operation and intelligent management, and embodies the concept of people-oriented. It has scientific significance for future construction of domestic Integrated Monitoring and Early Warning System (IMEWS) of urban rail transit.
基金Sponsored by National Youth Science Foundation(51408507)China Postdoctoral Science Foundation(2015M570385)
文摘According to the study on 39 sites of rail transit Line 3 in Chongqing, the sites are classifi ed into three types: residential type, business center type, traffi c hub type in this paper. The study shows that the sites have many problems such as discordance of land use, severity of spatial segregation, low rate of site utilization. To solve these problems, development approaches of site space resources within 1,000 m around the site area are further explored. The approaches include four aspects: characteristics of land use, functional composite, walking guide and shuttle transportation. In addition, appropriate planning and design methods are proposed.
文摘Based on the numerical simulation analysis, structure parameters of the high pressure fuel pump and common rail as well as flow limiter are designed and the GD-1 high pressure common rail fuel injection system is self-developed. Fuel injection characteristics experiment is performed on the GD-1 system. And double-factor variance analysis is applied to investigate the influence of the rail pressure and injection pulse width on the consistency of fuel injection quantity, thus to test whether the design of structure parameters is sound accordingly. The results of experiment and test show that rail pressure and injection pulse width as well as their mutual-effect have no influence on the injection quantity consistency, which proves that the structure parameters design is successful and performance of GD-1 system is sound.