Artykuły w czasopismach: „HIGH SPEED TRACK”

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Fazio, Alfred E., i J. L. Corbin. "Track Quality Index for High Speed Track". Journal of Transportation Engineering 112, nr 1 (styczeń 1986): 46–61. http://dx.doi.org/10.1061/(asce)0733-947x(1986)112:1(46).

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Zicha, Jan H. "High‐Speed Rail Track Design". Journal of Transportation Engineering 115, nr 1 (styczeń 1989): 68–83. http://dx.doi.org/10.1061/(asce)0733-947x(1989)115:1(68).

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Týfa, Lukáš, Jan Kruntorád i Ondřej Tomaschko. "Railway superstructure for high-speed rails". Acta Polytechnica CTU Proceedings 31 (14.07.2021): 53–57. http://dx.doi.org/10.14311/app.2021.31.0053.

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The construction of the track is solved as a conventional (with track ballast) or as a ballastless track (without track ballast). When deciding on the choice of the most suitable track design for high-speed rail, it is necessary to emphasize that with increasing line speed, the requirements for the quality of the track geometry increase, including the size of the deviations of individual geometric parameters of the track from the projected values. When assessing the choice of track structure – especially for high-speed rails – it is therefore necessary and correct to assess the total costs (investment and operational) for a sufficiently long time. DB Netz AG’s present experience with a ballastless track since its first implementation in 1972 in Rheda station, for almost 50 years, shows that the required lifetime of 60 years has its real justification. In addition, current research and development in the field of ballastless track is moving towards extending the life of ballastless track well beyond this limit. The paper is focused on the comparison a ballasted and ballastless track construction. It deals in more detail with evaluation of the advantages and disadvantages of a ballastless track construction. The main objective is to assess the use of ballastless track structure for the construction of high-speed lines.

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Li, Ting, Qian Su, Kang Shao i Jie Liu. "Numerical Analysis of Vibration Responses in High-Speed Railways considering Mud Pumping Defect". Shock and Vibration 2019 (7.05.2019): 1–11. http://dx.doi.org/10.1155/2019/9707909.

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As a newly appeared defect under slab tracks in high-speed railways, mud pumping weakens the support ability of the subgrade to slab track, bringing about deviations on the vibration responses of the vehicle, slab track, and subgrade. Therefore, this paper proposes a vehicle-slab track-subgrade coupled model based on the multibody simulation principle and the finite element theory to highlight the influences of mud pumping defect. As an external excitation to this model, random track irregularity is considered. In order to simulate the mud pumping defect, the contact between the concrete base and subgrade is described as a spring-damper system. This model is validated by field test results and other simulation results, and a very good agreement is found. The vibration responses of the vehicle, slab track, and subgrade under different mud pumping lengths and train speeds are studied firstly. The deviations of vibration responses in high-speed railways induced by mud pumping are then obtained, and the limited mud pumping length is put forward finally to provide a recommendation for maintenance works of high-speed railways in practice.

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Liang, Kang, Qunzhang Tu, Xinmin Shen, Juying Dai, Qin Yin, Jinhong Xue i Xuan Ding. "Modeling and Verification of Rolling Resistance Torque of High-Speed Rubber Track Assembly Considering Hysteresis Loss". Polymers 15, nr 7 (25.03.2023): 1642. http://dx.doi.org/10.3390/polym15071642.

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Due to the viscoelasticity of rubber materials, hysteresis loss due to deformation is the main reason for the rolling resistance of high-speed rubber tracks. Since the structure and material of high-speed rubber track assemblies are different from traditional tires and metal tracks, the rolling resistance theory of traditional wheeled and tracked vehicles is not applicable. Therefore, in order to determine the rolling resistance scientifically and accurately, the mechanism research of the rolling resistance of high-speed rubber track assembly is the key to the design of high-speed rubber crawler vehicles. In this paper, the stress–strain characteristics of rubber track under the action of compression, tension, bending, and driving were studied. The strain load spectrum of rubber tracks was established, and the strain cyclic load was extracted by the rainflow method. The temperature model of the rubber track was developed based on its dynamic characteristics. On the basis of energy conservation, the hysteresis loss of rubber is equivalent to the energy consumption of rolling resistance, and the theoretical model of rolling resistance of high-speed rubber track assembly is established. In accordance with the model above, the key influencing factors and changing trends of rolling resistance are analyzed, which provides a theoretical basis for the performance optimization of high-speed rubber track assembly.

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Krylov, V. V., A. R. Dawson, M. E. Heelis i A. C. Collop. "Rail movement and ground waves caused by high-speed trains approaching track-soil critical velocities". Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 214, nr 2 (1.03.2000): 107–16. http://dx.doi.org/10.1243/0954409001531379.

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The increased speeds of modern trains are normally accompanied with increased transient movements of the rail and ground, which are especially high when train speeds approach some critical wave velocities in the track-ground system. These transient movements may cause large rail deflections, as well as structural vibrations and associated noise in nearby buildings. There are two main critical wave velocities in the track-ground system: the velocity of the Rayleigh surface wave in the ground and the minimum phase velocity of bending waves propagating in the track supported by ballast, the latter velocity being referred to as the track critical velocity. Both these velocities can be exceeded by modern high-speed trains, especially in the case of very soft soil where both critical velocities become very low. The discussion in this paper focuses on the effects of transient rail deflections on associated ground vibrations in the cases of train speeds approaching and exceeding Rayleigh wave and track critical velocities. The obtained theoretical results are illustrated by numerical calculations for TGV and Eurostar high-speed trains travelling along typical tracks built on soft soil.

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Esveld, Coenraad. "Developments in High-Speed Track Design". IABSE Symposium Report 87, nr 12 (1.01.2003): 37–45. http://dx.doi.org/10.2749/222137803796328782.

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Zhang, Qin, Xiaoning Zhu i Li Wang. "Track Allocation Optimization in Multi-Direction High-Speed Railway Stations". Symmetry 11, nr 4 (1.04.2019): 459. http://dx.doi.org/10.3390/sym11040459.

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Track allocation optimization in railway stations is one of the most fundamental problems for scheduling trains, especially in multi-direction high-speed railway stations. With the construction of high-speed rail networks, this kind of station has become increasingly common. However, the track allocation depends not only on the station tracks, train timetable, and rolling stock plan, but also on the resources in the station throat area. As a result, an effective track allocation plan becomes significant but also difficult. In this paper, we consider all these factors to make the results more practicable and an integer linear model that minimizes the total occupation time of resources in the throat area is presented. A flexible track utilization rule is also adopted to this model to fit the characteristics of the multi-direction station. Meanwhile, a detailed explanation of resources’ occupation time is illustrated to facilitate the representation of the conflicting constraints. To resolve these issues, we use a commercial solver with its default parameters. A computational experiment of a station is conducted to verify the effectiveness of the proposed model. The resources utilization plan indicates that the capacity of a station is limited by the throat area, rather than by the station tracks.

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Gao, Yin, Hai Huang, Carlton L. Ho i James P. Hyslip. "High speed railway track dynamic behavior near critical speed". Soil Dynamics and Earthquake Engineering 101 (październik 2017): 285–94. http://dx.doi.org/10.1016/j.soildyn.2017.08.001.

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Li, Wei, Xuecheng Bian, Xiang Duan i Erol Tutumluer. "Full-Scale Model Testing on Ballasted High-Speed Railway: Dynamic Responses and Accumulated Settlements". Transportation Research Record: Journal of the Transportation Research Board 2672, nr 10 (13.07.2018): 125–35. http://dx.doi.org/10.1177/0361198118784379.

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High-speed trains generate much higher vibrations in track structures than conventional trains and intensive train passages (e.g., on the Beijing–Shanghai high-speed railway line where the train passage interval is less than 5 minutes) cause accumulated permanent settlement in the railway track substructures, which will decrease track performance and jeopardize the safety of trains. Since very few field measurements on ballasted high-speed railways are available in literature, this paper presents experimental results of vibration velocity, dynamic soil stress, and the accumulated settlement of a ballasted high-speed railway from a full-scale model testing facility with simulated trains moving loads at various speeds. A portion of a realistic ballasted railway consisting of track structure, ballast layer, subballast, embankment, and piled foundation was constructed in a larger box. An eight-actuator sequential loading system was used to generate equivalent vertical loadings on the track structure for simulating the dynamic excitations due to train movements. Dynamic stresses measured in the track substructure layers (ballast, subballast, and embankment) were found to be strongly dependent on train speeds especially for speeds higher than 144 km/h. It was found that both the vibration velocity and the dynamic soil stress were greatly amplified as the train speed increased to 300 km/h, and the ballast layer effectively reduced the vibrations transmitted from the track structure to underlying soil. The accumulated settlement of the substructure did not reach a stable state even after 100,000 moving train loads at a speed of 300 km/h.

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Šlapák, Jiří, i Tomáš Michálek. "Vehicle/track interaction under the conditions of high speed railway operation". Acta Polytechnica CTU Proceedings 31 (14.07.2021): 45–52. http://dx.doi.org/10.14311/app.2021.31.0045.

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This paper deals with the issue of dynamic effects of a high-speed railway vehicle on the track. Some aspects of vehicle/track interaction at higher speeds are described. In this context, a multi-body model of high-speed railway vehicle was created and several simulation scenarios were performed with this model. Furthermore, the simulations were evaluated with a focus on selected characteristics of the vehicle/track interaction.

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Zhu, Shengyang, Jun Luo, Mingze Wang i Chengbiao Cai. "Mechanical characteristic variation of ballastless track in high-speed railway: effect of train–track interaction and environment loads". Railway Engineering Science 28, nr 4 (30.11.2020): 408–23. http://dx.doi.org/10.1007/s40534-020-00227-6.

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AbstractDue to the fact that ballastless tracks in high-speed railways are not only subjected to repeated train–track dynamic interaction loads, but also suffer from complex environmental loads, the fundamental understanding of mechanical performance of ballastless tracks under sophisticated service conditions is an increasingly demanding and challenging issue in high-speed railway networks. This work aims to reveal the effect of train–track interaction and environment loads on the mechanical characteristic variation of ballastless tracks in high-speed railways, particularly focusing on the typical interface damage evolution between track layers. To this end, a finite element model of a double-block ballastless track involving the cohesive zone model for the track interface is first established to analyze the mechanical properties of the track interface under the loading–unloading processes of the negative temperature gradient load (TGL) followed by the same cycle of the positive TGL. Subsequently, the effect of wheel–rail longitudinal interactions on the nonlinear dynamic characteristics of the track interface is investigated by using a vehicle-slab track vertical-longitudinal coupled dynamics model. Finally, the influence of dynamic water pressure induced by vehicle dynamic load on the mechanical characteristics and damage evolution of the track interface is elucidated using a fluid–solid coupling method. Results show that the loading history of the positive and negative TGLs has a great impact on the nonlinear development and distribution of the track interface stress and damage; the interface damage could be induced by the wheel–rail longitudinal vibrations at a high vehicle running speed owing to the dynamic amplification effect caused by short wave irregularities; the vehicle dynamic load could produce considerable water pressure that presents nonlinear spatial–temporal characteristics at the track interface, which would lead to the interface failure under a certain condition due to the coupled dynamic effect of vehicle load and water pressure.

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DITZEL, AUKE, GERARD HERMAN i PAUL HÖLSCHER. "ELASTIC WAVES GENERATED BY HIGH-SPEED TRAINS". Journal of Computational Acoustics 09, nr 03 (wrzesień 2001): 833–40. http://dx.doi.org/10.1142/s0218396x01001133.

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High-speed trains can generate vibrations that propagate away from the track. We present an accurate and efficient method for computing the vibrations in an elastic half-space at both small and large distances from the track. The method takes possible oscillatory behavior of the train into account. We conclude that vibrations, generated by oscillating trains, can be observed at large distances from the track, even if the train speed is lower than the Rayleigh wave speed.

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Guo, Yi Shi, Zu Jun Yu i Hong Mei Shi. "Natural Vibration Analysis of High-Speed Railway Slab Tracks under Rail Longitudinal Force". Advanced Materials Research 706-708 (czerwiec 2013): 1443–49. http://dx.doi.org/10.4028/www.scientific.net/amr.706-708.1443.

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The slab track is the main structure of the high-speed railway track, the Inherent dynamic characteristics of which is of great significance to the research on the Vehicle-Track Coupling Dynamics. The assumptions of the modal function describing the natural vibration of the track is a necessary theoretical basis in analytic and numerical calculations for dynamics problems, which is more in accordance with the real situation, the more likely characteristic estimation are to be accurate. In this paper, with the method of combine matrix, the system characteristic equation of slab-track model is deduced, and the exact analytic formulas of frequency equation and modal function are obtained. Meanwhile the specific effects of the Rail longitudinal force on the vibration performance of the tracks are analyzed through instances. The results show that this approach is an effective analytic method, the solution of which is accurate. And the track parameters can be flexibly initialized, which is especially applicable for the condition of track parameters varying and longitudinal strain with distribution.

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Sung, Deok-Yong, i Sung-Cheon Han. "Fatigue life evaluation of continuous welded rails on concrete slab track in Korea high-speed railway". Advances in Structural Engineering 21, nr 13 (15.03.2018): 1990–2004. http://dx.doi.org/10.1177/1369433218762501.

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There is a rapidly increasing demand for continuous welded rails. Continuous welded rails provide a more suitable installation on concrete slab tracks and more rapid and smooth movement and reduce overall maintenance cost. During the relatively short period in which concrete slab tracks have been used in Korea, there has been no documented case of rail fracture caused by repeated loading. This makes the evaluation of rail fatigue life using field data more difficult. In this study, the rail bending stress developed during high-speed train operation is obtained through analysis of vehicle–track interaction, and the correlation is analyzed by performing multiple regression analysis on train speed and rail surface irregularities. Equations for predicting the rail bending stress with regard to train speed and rail surface irregularity were derived. The effects of vehicle speed, track support stiffness, and fracture probability on the fatigue life of continuous welded rails on a concrete slab track in Korea high-speed railway were analyzed.

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Javaid, Omer, i Dong-Ho Choi. "Effect of Track Irregularities on the Response of Two-Way Railway Tracks". Applied Sciences 10, nr 1 (18.12.2019): 11. http://dx.doi.org/10.3390/app10010011.

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In predicting the response of track from a moving train only one track is generally considered. However, the effect of ground vibrations from one track and its effect on the nearby tracks has not been studied completely. Therefore, in the present paper, the effect of track irregularities and speed on the prediction of two-way tracks response is investigated. For this purpose, a three-dimensional dynamic finite element (FE) model capable of simulating interactions between the train and track by using a nonlinear hertz contact method was developed. The model uses tensionless stiffness between the wheel and rail to couple them. The model components including the sleeper, ballast, and soil domain are represented by solid brick elements. The rails are modeled as 3D Euler–Bernoulli beam elements. An iterative numerical algorithm was established for the integrations of the train and track interface. A comparative analysis was performed at various speeds and rail surface irregularity wavelengths. With the increase in speed, the results showed a significant increase in the adjacent tracks response and can induce much larger track vibrations at high frequency.

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Atalan, Mucahit, Luke J. Prendergast, Athina Grizi i Nick Thom. "A Review of Numerical Models for Slab-Asphalt Track Railways". Infrastructures 7, nr 4 (18.04.2022): 59. http://dx.doi.org/10.3390/infrastructures7040059.

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Higher train speeds and heavier axle loads trigger elevated stresses and vibrations in the track, potentially increasing track deterioration rates and maintenance costs. Alternative track forms made of combinations of reinforced concrete and asphalt layers have been developed. A thorough understanding of the slab and asphalt tracks is needed to investigate track performance. Thus, analytical and numerical models have been developed and validated by many researchers. This paper reviews numerical models developed to investigate railway track performance. The synthesis of major finite element models is described in detail, highlighting the main components and their outputs. For slab track models, the use of a structural asphalt layer within the railway track remains an active research topic and firm conclusions on its efficacy are not yet available. It can be expected that slab track structures will also be affected by train-induced ground vibrations. There is thus a gap in the literature regarding the measurement of dynamic effects on high-speed railway lines, and further research is needed to investigate the dynamic behaviour of slab–asphalt track systems. In this review, novel solutions for mitigating the vibrations in high-speed rail are discussed and compared. The use of asphalt material in railways appears to have beneficial effects, such as increasing the bearing capacity and stiffness of the structure and improving its dynamic performance and responses, particularly under high-speed train loads.

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Siren, T., M. Dahlström i T. Cronvall. "High-speed train induced vibration measurements in fresh tunnel shotcrete layer". IOP Conference Series: Earth and Environmental Science 1124, nr 1 (1.01.2023): 012037. http://dx.doi.org/10.1088/1755-1315/1124/1/012037.

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Abstract Existing coastal railway track has been undergoing for renovation and improvement work aiming to raise train speed and shorten the travel time between Turku and Helsinki. The track has 16 existing tunnels of which 14 has been renovated between 2019 and 2021. Majority of the tunnels have been reinforced by system and shotcrete and rock bolts. The water seepage control has been solved by using PE sheets with additional 100 mm fibre shotcrete layer as fire protection layer. After the track and tunnel improvements, the track was test driven with two different trains: a high speed SM train unit and a two storey intercity train unit. The speeds used were higher than the current allowed speeds aiming to study the potential to increase the travel speed. One of the most restrictive parameters for the increase is the pressure shock of high speed train entering the tunnel. Too high pressure shock will cause inconvenience for the passengers and can cause damage in tunnel lining structures. Also currently no clear guideline exists what speed limits need to be used for trains entering tunnels with curing shotcrete. To study these matters the test run train units were instrumented including with pressure sensors. The conclusions about the pressure shocks are investigated briefly in the paper.

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Hodas, Stanislav. "Design of Railway Track for Speed and High-speed Railways". Procedia Engineering 91 (2014): 256–61. http://dx.doi.org/10.1016/j.proeng.2014.12.056.

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Teixeira, P. F., A. López-Pita, C. Casas, A. Bachiller i F. Robusté. "Improvements in High-Speed Ballasted Track Design". Transportation Research Record: Journal of the Transportation Research Board 1943, nr 1 (styczeń 2006): 43–49. http://dx.doi.org/10.1177/0361198106194300106.

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Zhai, Wanming, Kaiyun Wang, Zhaowei Chen, Shengyang Zhu, Chengbiao Cai i Gang Liu. "Full-scale multi-functional test platform for investigating mechanical performance of track–subgrade systems of high-speed railways". Railway Engineering Science 28, nr 3 (wrzesień 2020): 213–31. http://dx.doi.org/10.1007/s40534-020-00221-y.

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Abstract Motivated by the huge practical engineering demand for the fundamental understanding of mechanical characteristics of high-speed railway infrastructure, a full-scale multi-functional test platform for high-speed railway track–subgrade system is developed in this paper, and its main functions for investigating the mechanical performance of track–subgrade systems are elaborated with three typical experimental examples. Comprising the full-scale subgrade structure and all the five types of track structures adopted in Chinese high-speed railways, namely the CRTS I, the CRTS II and the CRTS III ballastless tracks, the double-block ballastless track and the ballasted track, the test platform is established strictly according to the construction standard of Chinese high-speed railways. Three kinds of effective loading methods are employed, including the real bogie loading, multi-point loading and the impact loading. Various types of sensors are adopted in different components of the five types of track–subgrade systems to measure the displacement, acceleration, pressure, structural strain and deformation, etc. Utilizing this test platform, both dynamic characteristics and long-term performance evolution of high-speed railway track–subgrade systems can be investigated, being able to satisfy the actual demand for large-scale operation of Chinese high-speed railways. As examples, three typical experimental studies are presented to elucidate the comprehensive functionalities of the full-scale multi-functional test platform for exploring the dynamic performance and its long-term evolution of ballastless track systems and for studying the long-term accumulative settlement of the ballasted track–subgrade system in high-speed railways. Some interesting phenomena and meaningful results are captured by the developed test platform, which provide a useful guidance for the scientific operation and maintenance of high-speed railway infrastructure.

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Chen, Jin, Ying Zhou, Guangxin Zhou i Bo Fu. "Experimental Vibration Investigation on High-Speed Railway Ballastless Track-Subgrade Structure". International Journal of Structural Stability and Dynamics 20, nr 07 (lipiec 2020): 2050081. http://dx.doi.org/10.1142/s0219455420500819.

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With the development of high-speed railways, the double-line mode of ballastless tracks is being adopted increasingly worldwide. In some sections where subgrades need to be laid, this type of line mode is also applied above the subgrade, thus forming double-line track-subgrade structure. In this structure, the subgrade on one side of the double-line is subjected to the eccentric pressure of the load when the unidirectional train is running (the most common operating condition in actual operation). When the subgrade contains embankment layer, the complexity of the problem is increased. Therefore, a 1:4 scale test model of the double-line ballastless track-subgrade system was constructed in this paper in order to study the dynamic responses of the double-line track-subgrade structure with embankment layer under the unidirectional high-speed train loads. By considering the similarity of shear wave velocities, a new uniform dynamic similarity method was adopted to design the track, subgrade and foundation models. The effects of a series of sine waves with 1–30[Formula: see text]Hz excitation frequency and three kinds of loading modes on the speed, soil stress and acceleration response of the track and subgrade were systematically investigated. The relationship between the effective composite values of velocity beneath the track and the depth was finally obtained. The results show that the dynamic stress attenuation of the subgrade bottom layer under larger axle loads are relatively faster. It is found that the dynamic stress attenuation of the subgrade bottom layer is relatively fast under the high-frequency uniform excitation of large axial heavy load.

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Els, Johan, Michele Truscott, Kobus van der Walt i Gerrie Booysen. "Establishing the Optimal Process Parameters for the Laser Sintering of Ti64 for Layer Thicknesses of 15 μm and 30 μm and Validation of a Melt Pool Simulation Model". Advanced Materials Research 1019 (październik 2014): 254–58. http://dx.doi.org/10.4028/www.scientific.net/amr.1019.254.

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Direct Metal Laser Sintering (DMLS) is a layer-by-layer Additive Manufacturing (AM) process that creates physical metal parts from three dimensional Computer Aided Design (CAD) data. For DMLS to be generally accepted by industry as a manufacturing technology, high mechanical integrity of final components needs to be demonstrated. Mechanical properties of manufactured components are directly affected by the quality of each individual laser sintered track of each consecutive layer. In this study, the optimal ratio of laser power and scanning speed on single tracks is determined for Titanium-6Al-4V powder on an EOSINT M270 DMLS machine for a layer thickness that varies between 15 μm and 30 μm. Two different laser powers, namely 150 W and 170 W were considered. Scanning speeds varied between 600 mm/s to 2000 mm/s with 200 mm/s intervals. The most stable tracks resulted from high laser power, slow scanning speed and thin powder distribution. The empirical data were compared to a melt pool width prediction program, which was found to underestimate track width at all scanning speeds and re-melting depth at low scanning speeds. Further, it was found that decreased powder thickness can be used with an increased scanning speed and high laser power. This strategy may be used to increase surface quality. The penetration data during fusion of the tracks onto the building platform further validates the quality of each sintered track.

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Liu, Chi, David Thompson, Michael J. Griffin i Mani Entezami. "Effect of train speed and track geometry on the ride comfort in high-speed railways based on ISO 2631-1". Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 234, nr 7 (15.08.2019): 765–78. http://dx.doi.org/10.1177/0954409719868050.

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The operational speeds of passenger trains have been increasing and now often exceed 300 km/h. Higher speeds can lead to increased vibration and reduced ride comfort for railway passengers. This study investigates the combined effect of speed and track geometry on vibration discomfort in high-speed trains. Railway vehicle dynamic models with various levels of complexity are used, with the measured geometry of a section of a high-speed track as an input. The models have been calibrated with vibration measurements carried out in a train running over this section of the track and then applied to predict the vibration discomfort at increased speeds. To evaluate the vibration discomfort at speeds up to 400 km/h, information on track geometry should include wavelengths up to at least 150 m. Vertical irregularities have the greatest effect at all speeds but lateral irregularities are also important. Both the vertical and lateral irregularities of a high-speed track should be controlled at wavelengths of 50–100 m that excite rigid modes of the car body, corresponding to frequencies of typically 1–2 Hz. Additionally, vertical irregularities with wavelengths of 5–12 m that excite the fundamental flexible mode of the car body, typically around 10–15 Hz, should also be controlled. The effects of cant, the rates of change of cant, and the radius of vertical curves are also evaluated although they only have a small effect on vibration discomfort.

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Zhang, Xu, Chunfa Zhao, Wanming Zhai, Can Shi i Yang Feng. "Investigation of track settlement and ballast degradation in the high-speed railway using a full-scale laboratory test". Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 233, nr 8 (11.12.2018): 869–81. http://dx.doi.org/10.1177/0954409718812231.

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This paper presents a full-scale laboratory test for investigating the track settlement and ballast degradation of the ballasted track–subgrade system on the high-speed railways. The test was carried out on a full-scale test platform with a ballasted track–subgrade system constructed exactly according to the construction standards of high-speed railways in China. In this test, four million cycles of cyclic loads simulating repeated high-speed train loads with an axle load of 140 kN were applied to the ballasted track–subgrade system through a specialized loading system. The vertical displacement and settlement of the rail, the sleepers and the subgrade at various sections and depths were recorded during the test. The test results show that the settlement of the high-speed railway ballasted track is very less. A logarithmic model was proposed for predicting the settlement of the high-speed railway ballasted track by fitting the measured data. Moreover, some painted ballast samples were embedded into the tested track to investigate the ballast degradation. After the test, it was found that more than 80% of the painted ballast grains remained intact and less than 20% were degraded. Four different ballast degradation phenomena were observed: corner or edge breakage, surface scratch, surface crack and the production of fine particles. The test results indicate that the high-speed railway ballasted tracks in China are very stable and the settlement is less under long-term cyclic loads, which could significantly benefit the track geometry and the railway maintenance work.

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Yan, Bin, Gong-lian Dai i Hua-ping Zhang. "Beam-track interaction of high-speed railway bridge with ballast track". Journal of Central South University 19, nr 5 (27.04.2012): 1447–53. http://dx.doi.org/10.1007/s11771-012-1161-8.

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Dai, Jian, Kok Keng Ang, Minh Thi Tran, Van Hai Luong i Dongqi Jiang. "Moving element analysis of discretely supported high-speed rail systems". Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 232, nr 3 (1.03.2017): 783–97. http://dx.doi.org/10.1177/0954409717693147.

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In this paper, a computational scheme in conjunction with the moving element method has been proposed to investigate the dynamic response of a high-speed rail system in which the discrete sleepers on the subgrade support the railway track. The track foundation is modeled as a beam supported by uniformly spaced discrete spring-damper units. The high-speed train is modeled as a moving sprung-mass system that travels over the track. The effect of the stiffness of the discrete supports, train speed, and railhead roughness on the dynamic behavior of the train–track system has been investigated. As a comparison, the response of a continuously supported high-speed rail system that uses a foundation stiffness equivalent to that of a discretely supported track has been obtained. The difference in results between the “equivalent” continuously supported and the discretely supported high-speed rails has been compared and discussed. In general, the study found that a high-speed train that travels over a discretely supported track produces more severe vibrations than that travels over a continuously supported track of equivalent foundation stiffness.

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Khairallah, Diana, Olivier Chupin, Juliette Blanc, Pierre Hornych, Jean-Michel Piau, Diego Ramirez Cardona, Alain Ducreau i Frederic Savin. "Monitoring and Modeling Railway Structures on High-Speed Lines with Asphalt Concrete Underlay: A Study on the Bretagne–Pays de la Loire Line". Transportation Research Record: Journal of the Transportation Research Board 2674, nr 12 (grudzień 2020): 600–607. http://dx.doi.org/10.1177/0361198120960472.

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The design and durability of high-speed railway lines is a major challenge in the field of railway transportation. In France, 40 years of feedback on the field behavior of ballasted tracks led to improvements in the design rules. However, the settlement and wear of ballast, caused by dynamic stresses at high frequencies, remains a major problem on high-speed tracks leading to high maintenance costs. Studies have shown that this settlement is linked to the high acceleration produced in the ballast layer by high-speed trains traveling on the track, disrupting the granular assembly. The “Bretagne–Pays de la Loire” high-speed line (BPL HSL), with its varied subgrade conditions, represents the first large-scale application of asphalt concrete (GB) as the ballast sublayer. This line includes 77 km of conventional track with a granular sublayer of unbound granular material (UGM) and 105 km of track with an asphalt concrete sublayer under the ballast. During construction, instruments such as accelerometers, anchored deflection sensors, and strain gages, among others, were installed on four sections of the track. This paper examines the instrumentation as well as the acquisition system installed on the track. The data processing is explained first, followed by a presentation of the ViscoRail software, developed for modeling railway tracks. The bituminous section’s behavior and response is modeled using a multilayer dynamic response model, implemented in the ViscoRail software. A good match between experimental and calculated results is highlighted.

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Tan, Chang Jian, i Wen Hong Ji. "Research into the Parameter Influence on Coupled Vibration Analysis of High Speed Train and Bridge". Applied Mechanics and Materials 90-93 (wrzesień 2011): 884–89. http://dx.doi.org/10.4028/www.scientific.net/amm.90-93.884.

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To investigate the characteristic of coupled vibration of high speed train and bridge, the effect of the railway track irregularity, different train speeds were investigated based on analyzing the coupled vibration of the JR300 high speed train-bridge system The results show that the vertical acceleration of train will be influenced much when the railway track irregularity is considered. The study suggests that the dynamic response of the train and bridge decreases with an increase in the train speed, when the train speed is at a certain zone, and the dynamic response increase rapidly with the increased train speed when the train speed is out of this zone.

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30

Chang, Chao, Liang Ling, Zhaoling Han, Kaiyun Wang i Wanming Zhai. "High-Speed Train-Track-Bridge Dynamic Interaction considering Wheel-Rail Contact Nonlinearity due to Wheel Hollow Wear". Shock and Vibration 2019 (31.10.2019): 1–18. http://dx.doi.org/10.1155/2019/5874678.

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Wheel hollow wear is a common form of wheel-surface damage in high-speed trains, which is of great concern and a potential threat to the service performance and safety of the high-speed railway system. At the same time, rail corridors in high-speed railways are extensively straightened through the addition of bridges. However, only few studies paid attention to the influence of wheel-profile wear on the train-track-bridge dynamic interaction. This paper reports a study of the high-speed train-track-bridge dynamic interactions under new and hollow worn wheel profiles. A nonlinear rigid-flexible coupled model of a Chinese high-speed train travelling on nonballasted tracks supported by a long-span continuous girder bridge is formulated. This modelling is based on the train-track-bridge interaction theory, the wheel-rail nonelliptical multipoint contact theory, and the modified Craig–Bampton modal synthesis method. The effects of wheel-rail nonlinearity caused by the wheel hollow wear are fully considered. The proposed model is applied to predict the vertical and lateral dynamic responses of the high-speed train-track-bridge system under new and worn wheel profiles, in which a high-speed train passing through a long-span continuous girder bridge at a speed of 350 km/h is considered. The numerical results show that the wheel hollow wear changes the geometric parameters of the wheel-rail contact and then deteriorates the train-track-bridge interactions. The worn wheels can increase the vibration response of the high-speed railway bridges.

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31

Ivanchenko, I. I., i S. N. Shapovalov. "352225 THE DEVELOPMENT OF MODELS FOR HIGH SPEED RAILWAY TRACK DYNAMICS(Infrastructure,Technical Session)". Proceedings of International Symposium on Seed-up and Service Technology for Railway and Maglev Systems : STECH 2009 (2009): _352225–1_—_352225–7_. http://dx.doi.org/10.1299/jsmestech.2009._352225-1_.

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Dai, Jian, Kok Keng Ang, Van Hai Luong, Minh Thi Tran i Dongqi Jiang. "Out-of-Plane Responses of Overspeeding High-Speed Train on Curved Track". International Journal of Structural Stability and Dynamics 18, nr 11 (22.10.2018): 1850132. http://dx.doi.org/10.1142/s0219455418501328.

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This paper presents a numerical study on the out-of-plane responses of a high-speed train running on a curved railway track segment using the moving element method. The accuracy and efficiency of the proposed computation model presented herein are compared with available analytical results from the literature and a finite element solver based on a simplified moving load model. Thereafter, a half-railcar moving sprung-mass model and a double-rail track-foundation model are presented to investigate the behavior of a high-speed train traversing a curved track, particularly when the train speed is greater than the design speed of the curved track segment. The results show that the train speed and severity of track irregularity significantly affect the contact forces on the rails. This paper also presents a case of a railcar overturning when the train speed is greater than 2.5 times the design speed of a curved track segment.

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Lapina, L. G., I. Yu Malysheva i T. F. Mokrii. "Study of the possibility of using disturbances formed from recorded track irregularities in the calculation of high-speed rail vehicle dynamics". Technical mechanics 2022, nr 2 (30.06.2022): 115–22. http://dx.doi.org/10.15407/itm2022.02.115.

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An urgent task for Ukraine during the post-war reconstruction of the country will be the upgrade of the entire railway transportation system, in particular the development of high-speed passenger traffic. The prediction of the dynamic performance of high-speed rail vehicles calls for the formation of new input arrays (track-induced disturbances) that would account for more stringent track geometry requirements. The aim of this work is to study the possibility of using track irregularities recorded in real sections of the Ukrainian railways to construct the components of track-induced disturbances acting on a rail vehicle moving at a high speed. This paper considers in detail standard specifications for the geometric parameters of a track suitable for high-speed traffic. The data are contained in the Standard DSTU EN 13848-5:2018, which is a European standard adopted in Ukraine as a national one by confirmation. Using the track subsidence and alignment irregularities recorded by a track measurement car in a number of sections of the Pryndiprovska railway during a scheduled track inspection, processes of actual vertical and horizontal irregularities were formed. The quality of those sections had not require any speed limitation. Irregularity parameters for those sections were calculated. A comparison between the calculated parameters and those specified by the DSTU EN 13848-5:2018 showed that among the sections considered there exist ones that meet the track geometry requirements and allow speeds at least up to 230 km/h. The use of the irregularities in the selected track sections as disturbance components in calculations was tested by the example of determining the ride performance of a standard passenger car with KVZ-TsNII-M trucks. The calculated results showed the possibility of using the generated disturbances in numerical calculations of the dynamic performance of rail vehicles at increased speeds and at the same time confirmed the need for new engineering solutions on the design of rail vehicles capable of operating at such speeds.

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Wang, Xiaohui, Jianwei Yang, Jinhai Wang, Yanxue Wang i Guiyang Xu. "An Incentive Factor-Based Dynamic Comprehensive Evaluation on a High-Speed Railway Track". Applied Sciences 10, nr 16 (11.08.2020): 5546. http://dx.doi.org/10.3390/app10165546.

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Peak management and mean management are common ways to manage the quality of high-speed railway tracks at present. The most popular method for evaluating such tracks is the track quality index (TQI) method, which can reflect the overall state of the equipment to a certain extent. However, this method is likely to ignore some potential risks that threaten the operation of a high-speed train. For more effective risk identification, an incentive factor-based dynamic comprehensive evaluation (DCE) method was introduced to assess the geometric parameters of a high-speed railway track. Moreover, the weights of geometric parameters were computed by a combination of the analytic hierarchy process (AHP) and entropy based on the correlation coefficient. The proposed method can highlight the sensitivity index of the geometric parameters, which is an advantage over the TQI method. A case study of a high-speed railway track was performed using the two methods, and the results were verified with the original data. It was found that the TQI method identified only one obvious risk while the proposed method identified one obvious risk and two potential risks. This suggests that the proposed method is more accurate in identifying the risky sections than the TQI method.

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35

Deng, Hua Xia, Lai Jun Zhou, Shi Yu Zhao, Wei Hua Li, Shuai Shuai Sun, Jin Zhang i Lian Dong Yu. "The Dynamic Behavior of High Speed Train Using Magnetorheological Technology on the Curve Track". Applied Mechanics and Materials 782 (sierpień 2015): 210–18. http://dx.doi.org/10.4028/www.scientific.net/amm.782.210.

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The era of high speed railway has come and the most important issue of the high speed train is the safety, which is directly related to billions of families. One of the most serious threats to the safety of the high speed train is the vibration of train body at curve track, which may cause the train off the track. Semi-active vibration control method is a possible solution compared with active control method which has robust problem and passive control method which has efficiency issue. Magnetorheological technology is a typical semi-active vibration control method which has been widely used in the automobile, architectural construction and aerospace. The high speed train using magnetorheological technology has not been fully investigated especially for the dynamic performance at curve track. In this paper, a high-speed train model with MRF dampers is simulated by a combined ADAMS and MATLAB simulation. The dynamic performance of high speed train operating at different speeds and turning radius is investigated to reveal the mechanism of how the MRF damper affects the train’s stability and vibration. The results show that the semi-active suspension installed with MRF dampers substantially improves the stability and dynamic performance of the train at curve track.

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36

Diachenko, Leonid, Andrey Benin i Anastasia Diachenko. ""Track-Bridge" Interaction Problems in High Speed Bridge Design". International Journal of Engineering & Technology 7, nr 3.19 (7.09.2018): 194. http://dx.doi.org/10.14419/ijet.v7i3.19.17336.

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Track-bridge interaction problems have a main role in the design of bridges on high speed railways (HSR). In this paper, a technique is described for performing calculations of the interaction of the elements of the "bridge-jointless track" system. The complexity of these calculations lies in the nonlinear relationship between the bridge spans and the railway track. The characteristics of these relationships are largely determined by climatic factors (summer and winter conditions), as well as the presence of temporary loading on the bridge. The results of the interaction "bridge-jointless track" system are presented at temperature and train impacts for the characteristic types of bridge structures in the form of multi-span beams and continuous beams. The influence of the length, the construction scheme, the longitudinal stiffness of the intermediate supports on the magnitude of the forces arising in the rails of the continuous path is shown. Based on the performed calculations, conclusions were drawn about the characteristic modes of operation of the "bridge-jointless track" system and recommendations were made on constructive measures reducing efforts in rails.

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37

NAKATA, Daisuke, Kenji NISHINE, Kaoru TATEOKE, Nobuhiro TANATSUGU i Kazuyuki HIGASHINO. "Aerodynamic Measurement on the High Speed Test Track". TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN 12, ists29 (2014): Tg_5—Tg_10. http://dx.doi.org/10.2322/tastj.12.tg_5.

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Ižvolt, Libor, Jana Ižvoltová i Janka Šestáková. "Influence of Construction of Railway Superstructure on Railway Quality". Applied Mechanics and Materials 617 (sierpień 2014): 54–59. http://dx.doi.org/10.4028/www.scientific.net/amm.617.54.

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The operation of railway tracks is historically confirmed that the classic structure of the railway superstructure is capable to ensure operational capability of standard railway tracks for a relatively long period of time (railways tracks to speed of 160 km.h-1). Such a railway track and its track is considered the railway track with a classic structure of the railway superstructure, where track removal is stored in the ballast. In the case of high operating and axle load, increasing track speed and requirements for safety of operation, which are associated with high requirements on the track geometry, it appears that such structure has its operational (in terms of guaranteeing the long-term safety and reliability of the railway track) and economic (in terms of the cost of maintenance of railway track) limits. "Floating" placement of the track removal during each passage of a rail vehicle, or train leads to the growth of dynamic horizontal and vertical forces that cause gradual degradation of track geometry, what subsequently leads to restless journey of moving rail vehicles. Elimination of imperfections in track geometry - the quality of the railway track - forces the operators to remove such imperfections of railway track in time and financially consuming maintenance work in certain periods. However, it is sufficient if only the weakest element of classic railway superstructure is replaced in the railway, and it is the track ballast using other more appropriate component representing no elastic and plastic behaviour. The structure is such replacement, in which the track removal is concreted (monolithic structure) or stored on a concrete or asphalt bearing layer (layered structure), namely structural design, which is referred to as unconventional railway superstructure. The structure of railway superstructure is characterized by cross sleepers used in a modified shape or they are not part of it at all. Currently, thus conceived railway track is referred to as a slab track (hereinafter referred to as the "ST"), which requires flexibility of the railway superstructure for the system of the wheel/rail secured using elastic elements disposed between the rail and the sleeper and/or under the sleeper. In general, the structure of ST has been currently applied mainly to high-speed track and the tracks that have high operational load, where the cost of maintaining the track with the classic structure of the railway superstructure strongly grows. At the same time, however, this structure also promotes in the upgraded sections of the standard tracks (track speed to 160 km.h-1), especially in track sections conducted in tunnels, as there are located the required properties of the ballast that do not demonstrate subsidence. The subgrade without a drop also offers for application of the ST structure bridges, and therefore, the application of this structure is also possible in these track sections.

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Wang, Xiu Fang, Jin Ye Peng, Bin Chen i Wei Qi. "Tracking Algorithm Design and Comparison of High Speed High Maneuvering Target". Applied Mechanics and Materials 713-715 (styczeń 2015): 2053–57. http://dx.doi.org/10.4028/www.scientific.net/amm.713-715.2053.

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Aiming at the problem that the traditional tracking method cannot track high speed high maneuvering target effectively, one modified fixed structure multiple model algorithm (M-FSMM) and one modified variable structure multiple model (M-VSMM) algorithm were proposed. The Constant Velocity (CV) model, Current Statistical (CS) and Modified Coordinate Turn (MCT) model were adopted in the M-FSMM algorithm, by means of Connected Graph (CG) thinking, the model connected graph was made up by models that can describe possible motion, the connected relation was set up and model self-adapting was designed to carry out the variable structure tracking that can quickly jump between models. Monte Carlo simulation results show that the two methods can track high speed high maneuvering target effectively, the computational quantum of M-FVMM algorithm is larger but the tracking accuracy and stability are better than the M-FSMM algorithm. They can be used to track near space hypersonic targets.

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Shiau, Yan Chyuan, Ron Chen, Ming Hsi Lin i Chih Ming Huang. "Study on Precast Slab Track for Taiwan High Speed Rail". Applied Mechanics and Materials 214 (listopad 2012): 276–81. http://dx.doi.org/10.4028/www.scientific.net/amm.214.276.

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High Speed Rail significantly saves transportation time between cities in which a stable slab track is an essential and important component. This article introduces the quality management on production of precast tracks system, which can act as a reference and application for the concrete industry in Taiwan. Case study is used to investigate the major content of this project which includes quality management, organizational structure, material management, process management and inventory management. Some other key factors are discussed which assure the success of Taiwan High Speed Rail project such as comprehensive plan in advance, strictly execution according to written document, and looking at the bigger picture & performing from the details and putting training into practice.

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41

Zhi-Chen, Wang, Song Ying i Wang Jian-Xi. "Relation Between Track Irregularity of Speed-Increased Railway and Dynamic Speed Limits Through Simulation". Open Mechanical Engineering Journal 8, nr 1 (16.09.2014): 197–200. http://dx.doi.org/10.2174/1874155x01408010197.

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Based on the vehicle-track coupled dynamics theory and the corresponding simulation software ADAMS/Rail software package, a vehicle-track coupling system model is established, and the track irregularity is introduced to the coupling system model as an excitation source. Firstly, the dynamic responses of speed-increased railway vehicle and track components due to different types of track irregularity are obtained. Secondly, the sensitive wavelength of different track irregularities in high-speed operation is discussed. Finally, suggestions about the maximum operation speed to meet the standards value of daily maintenance target, comfortable value, emergency repair and speed management target are put forward.

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42

Wang, Xuejun, Jianghua Pu, Peng Wu i Mingfang Chen. "Modeling of Coupling Mechanism between Ballast Bed and Track Structure of High-Speed Railway". Mathematical Problems in Engineering 2020 (21.02.2020): 1–12. http://dx.doi.org/10.1155/2020/9768904.

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In this paper, a discrete and continuous body coupling algorithm is used to study the dynamic contact characteristics between ballasts and between ballasts and track structures. Firstly, the three-dimensional fine modeling of ballast particles is realized based on the three-dimensional laser scanning method, and then through the discrete and continuum coupling algorithm from the micro-macro point of view, a multiscale and unified particle-track structure coupling model is established. Based on the coupling model, the macro- and microdynamic characteristics of the ballast bed and the mechanical characteristics of the track structure under the dynamic load of high-speed trains with different driving speeds are studied. It is shown that the cumulative settlement of the ballast bed is directly proportional to the contact force and rotation speed of the ballast, and the faster the driving speed is, the greater the cumulative deposition speed and cumulative settlement of the ballast are. The contact force between the ballast and sleeper mainly comes from the bottom of the sleeper, and its contact force and contact strength increase with the increase of driving speed.

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43

Mo, Ye, Yi Zhuo i Shunlong Li. "Local Track Irregularity Identification Based on Multi-Sensor Time–Frequency Features of High-Speed Railway Bridge Accelerations". Sustainability 15, nr 10 (18.05.2023): 8237. http://dx.doi.org/10.3390/su15108237.

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Shortwave track diseases are generally reflected in the form of local track irregularity. Such diseases will greatly impact the train–track–bridge interaction (TTBI) dynamic system, seriously affecting train safety. Therefore, a method is proposed to detect and localize local track irregularities based on the multi-sensor time–frequency features of high-speed railway bridge accelerations. Continuous wavelet transform (CWT) was used to analyze the multi-sensor accelerations of railway bridges. Moreover, time–frequency features based on the sum of wavelet coefficients were proposed, considering the influence of the distance from the measurement points to the local irregularity on the recognition accuracy. Then, the multi-domain features were utilized to recognize deteriorated railway locations. A simply-supported high-speed railway bridge traversed by a railway train was adopted as a numerical simulation. Comparative studies were conducted to investigate the influence of vehicle speeds and the location of local track irregularity on the algorithm. Numerical simulation results show that the proposed algorithm can detect and locate local track irregularity accurately and is robust to vehicle speeds.

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44

Li, Bin, i Xue Yi Liu. "Random Vibration Properties of High-Speed Railway Vehicle Considering Random Parameters of Track Structure". Applied Mechanics and Materials 321-324 (czerwiec 2013): 62–66. http://dx.doi.org/10.4028/www.scientific.net/amm.321-324.62.

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Applied theory of vehicle/track coupled dynamic, random vibration properties of high-speed railway vehicles are researched in random parameters of fastener and ballast stiffness obeyed normal distribution and track irregularity combined the sample of artificial shortwave and the sample of low disturbance irregularity of high-speed railway in German with train speed increase. The results show that dynamic interaction of vehicle/track system and vibration responses of railway vehicle are increased with train speed increase, but the increase of wheel-set acceleration is much more. The parameters of high speed railway track structure (especially fastener and ballast stiffness) had much more impact to random vibration responses of vehicle/track system, so they should be optimized and remained in a narrow range.

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45

Cassirame, Johan, Hervé Sanchez i Jean-Benoit Morin. "The Elevated Track in Pole Vault: An Advantage During Run-Up?" International Journal of Sports Physiology and Performance 13, nr 6 (1.07.2018): 717–23. http://dx.doi.org/10.1123/ijspp.2016-0724.

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Background: Approach speed is a major determinant of pole-vault performance. Athletic jump events such as long jump, triple jump, and pole vault can utilize an elevated track for the runway. Feedback from athletes indicates a benefit of using an elevated track on their results. However, there is no evidence that elevated tracks increase athletes’ performance. Purpose: To investigate the potential advantage of using an elevated track during elite pole-vault competitions on run-up speed parameters. Methods: Performance and run-up criteria (speed, stride rate, contact, and aerial time) were measured from 20 high-level male pole-vaulters during official competitions on either a regular or an elevated track. Parameters comparisons were made between both conditions, and run-up parameters were confronted to speed modification on the elevated track. Results: Statistical analyses indicated that for the elevated track, there was a small improvement in final speed (1.1%), stride rate (1.1%), and takeoff distance (3.1%) and a small reduction in aerial time (−1.9%). The study highlighted different individual responses depending on athletes’ capabilities. The authors noted that speed improvement was largely correlated with stride-rate improvement (r = .61) and contact-time reduction (r = −.51) for slower athletes. Conclusions: Elevated tracks can increase final approach speed in pole vault and positively influence performance. Interindividual responses were observed in these findings.

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Higueras Martínez, Ángel. "El montaje de la vía de alta velocidad". Informes de la Construcción 44, nr 420 (30.08.1992): 49–66. http://dx.doi.org/10.3989/ic.1992.v44.i420.1324.

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Jiang, Bin, Min Li Zheng, Li Qiang Gu i Shu Cai Yang. "Research on the Cutting Track of Cutter and Fuzzy Comprehensive Evaluation for High Speed Ball-End Milling". Materials Science Forum 532-533 (grudzień 2006): 293–96. http://dx.doi.org/10.4028/www.scientific.net/msf.532-533.293.

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According to the principle producing the cutting track of cutter, to study the influence of the cutting track of cutter on the process of high speed ball-end milling, the single-factor models for evaluating the cutting track of cutter are established. Adopting four kinds of the typical cutting track of cutter, the experiment of high speed ball-end milling is processed. The model of multi-ply fuzzy comprehensive evaluation for the cutting track of cutter is established, fuzzy comprehensive evaluation for the cutting track of high speed ball-end milling cutter is accomplished by the application of fuzzy mathematics theory. Results show that the cutting contact curve of cutter affects directly the process of high speed ball-end milling, fuzzy and uncertain properties exist in the evaluation for the cutting track of cutter. The optimum cutting track can be selected by multi-ply fuzzy comprehensive evaluation for the cutting track of high speed ball-end milling cutter.

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Zhang, Xinchun, Ximin Cui i Bo Huang. "The Design and Implementation of an Inertial GNSS Odometer Integrated Navigation System Based on a Federated Kalman Filter for High-Speed Railway Track Inspection". Applied Sciences 11, nr 11 (4.06.2021): 5244. http://dx.doi.org/10.3390/app11115244.

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The detection of track geometry parameters is essential for the safety of high-speed railway operation. To improve the accuracy and efficiency of the state detector of track geometry parameters, in this study we propose an inertial GNSS odometer integrated navigation system based on the federated Kalman, and a corresponding inertial track measurement system was also developed. This paper systematically introduces the construction process for the Kalman filter and data smoothing algorithm based on forward filtering and reverse smoothing. The engineering results show that the measurement accuracy of the track geometry parameters was better than 0.2 mm, and the detection speed was about 3 km/h. Thus, compared with the traditional Kalman filter method, the proposed design improved the measurement accuracy and met the requirements for the detection of geometric parameters of high-speed railway tracks.

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Zhang, Jiamin, i Jiarui Zhang. "Comprehensive Evaluation of Operating Speeds for High-Speed Railway: A Case Study of China High-Speed Railway". Mathematical Problems in Engineering 2021 (3.02.2021): 1–16. http://dx.doi.org/10.1155/2021/8826193.

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This paper proposes the indicator systems and integrated desirability framework for comprehensive evaluation towards the operating speeds of high-speed railway (HSR). Speed is a crucial piece in the characterization of the HSR system. The debate about what is the most appropriate operating speed continues. The established indicator systems and integrated desirability framework can comprehensively evaluate the HSR operating speeds from stand points of the economic efficiency, operational efficiency, track capacity, operational security, and environment impact. Moreover, the integrated desirability framework, which is a combination of entropy-analytical hierarchy procedure (EAHP) and technique for order preference by similarity to ideal solution (TOPSIS), can output some references for selecting the most suitable speed regimes of HSR. The application of the desirability framework to the case of China high-speed railway (CHSR) is demonstrated concretely. Based on the case study of CHSR, the comprehensive analysis of the effectiveness of the indicator systems on HSR operating speeds is carried out. The case study shows that the proposed indicator systems and integrated desirability framework can be used to evaluate comprehensively the HSR operating speeds under various conditions.

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Shkurnikov, Sergey, i Olga Morozova. "On interaction of a rolling stock and geometrical parametres of high-speed networks’ route". Bulletin of scientific research results, nr 3 (17.10.2017): 96–104. http://dx.doi.org/10.20295/2223-9987-2017-3-96-104.

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Objective: Due to the lack of global experience of holding on one track high-speed passenger trains (moving at a speed up to 400 km/h), high-speed passenger trains (moving at a speed up to 250 km/h) and special freight trains (accelerating to a speed of more than 200 km/h), the only possible way of studying the influence of a train on a track is computer simulation modeling. The analysis of the existing computer programs was carried out and the most effective programme for the solution of combined train movement was selected. Methods: Simulation modeling was applied. On the basis of the obtained model the possibility of “Universal mechanism” software practical application was considered. Results: A test simulation model of a high-speed train carriage was developed in “Universal mechanism” software application. Preliminary results showed the possibility of its usage for the study of a high-speed train and track interaction. Practical importance: Modern computer technologies make it possible to solve the tasks of dynamic interaction with a high degree of accuracy. Among the variety of software used for the study of dynamic behavior of a railway vehicle in Russia, “Universal mechanism” software application is of wide popularity and may be used for the study of dynamic behavior of different types of trains on railway tracks of different plans and profiles.

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