scholarly journals Optimisation of slab track design considering dynamic train–track interaction and environmental impact

2022 ◽  
Vol 254 ◽  
pp. 113749
Author(s):  
Emil Aggestam ◽  
Jens C.O. Nielsen ◽  
Karin Lundgren ◽  
Kamyab Zandi ◽  
Anders Ekberg
2020 ◽  
Vol 306 ◽  
pp. 02003
Author(s):  
Haoran Xie ◽  
Bin Yan ◽  
Jie Huang

In order to investigate the vertical dynamic response characteristics of train-track-bridge system on CWR (Continunously Welded Rail) under dynamic load of train on HSR (High-Speed Railway) bridge. Based on the principle of vehicle train-track-bridge coupling dynamics, taking the 32m simply supported bridge of a section of Zhengzhou-Xuzhou Passenger Dedicated Line as an example, the finite element software ANSYS and the dynamic analysis software SIMPACK are used for co-simulation, and bridge model of the steel spring floating slab track and the CRTSIII ballastless track (China Railway Track System) considering the shock absorbing steel spring, the limit barricade and the contact characteristics of track structure layers are established. On this basis, in order to study the dynamic response laws of the design of ballastless track structure parameters to the system when the train crosses the bridge and provide the basis for the design and construction, by studying the influence of the speed of train on the bridge, the damage of fasteners and the parameters of track structure on the train-track-bridge system, the displacement of rail, vertical vibration acceleration and wheel-rail force response performance are analyzed. Studies have shown that: At the train speed of 40 km/h, the displacement and acceleration of the rail and track slab in the CRTSIII ballastless track are smaller than the floating slab track structure, but the floating slab track structure has better vibration reduction performance for bridges. The acceleration of rail, track slab and bridge increases obviously with the increase of train speed, the rail structure has the largest increasement. Reducing the stiffness of fasteners could decrease the vertical acceleration response of the steel spring floating slab track system, the ability to absorb shock can be enhanceed by reducing the stiffness of the fastener appropriately. Increasing the density of the floating slab can increase the vertical acceleration of the floating slab and the bridge, thereby decreasing the vibration amplitude of the system.


Author(s):  
J Blanco-Lorenzo ◽  
J Santamaria ◽  
E G Vadillo ◽  
O Oyarzabal

The dynamic performance of a ballasted track and three types of slab track is analysed and compared by means of a comprehensive dynamic model of the train–track system, generated using two commercial analysis software packages: the commercial multibody system (MBS) analysis software SIMPACK and the finite element method (FEM) analysis software NASTRAN. The use of a commercial MBS software makes it possible to include, in a reliable way, models of advanced non-linear wheel–rail contact as well as complex elements or joints in the vehicle model, while the FEM the flexibility of the rail and the slab to be taken into account. As a result, a combined MBS–FEM representation of the vehicle–track model is integrated into the MBS software, which allows for the study of dynamic phenomena in a wide frequency range. In this study, other simpler approaches for modelling the dynamic vehicle–track interaction are also considered, such as pure multibody or FE representations of the whole vehicle–track system. The quality of the results obtained with the different types of models used is analysed, and some conclusions are put forth regarding the possible validity of rather simple train–track interaction model types under certain conditions as well as the most suitable configuration of the most complex models.


Author(s):  
Zhaowei Chen ◽  
Wanming Zhai ◽  
Qiang Yin

Pier settlement causes deformation of bridge structures, and further distorts the track structures placed on bridge decks, which may greatly affect the service life of the tracks and safe operation of trains. This study analyzes track stresses and vehicle dynamic responses in train–track–bridge system with pier settlement and determines the pier settlement safe value for high-speed railways with China Railway Track System (CRTS) II slab tracks. First, a detailed train–track–bridge dynamic model is established based on the train–track–bridge dynamic interaction theory. Verified with field experimental results, the model is utilized to calculate the dynamic responses of the vehicle–track–bridge system with different pier settlement values. Finally, the safe value of the pier settlement in the CRTS II slab track railway line is determined according to the limit of the vehicle dynamic indicators and the structural stresses of tracks. The results show that the vertical acceleration of the car body is more sensitive to pier settlement among all the vehicle dynamic indicators. Structural stresses of tracks caused by pier settlement appear at the positions of the pier with settlement and its two adjacent piers. The effect of train loads on the track stresses is much smaller than that of the pier settlement. It is important to adopt the structural stresses of tracks as the evaluation criteria of the pier settlement safe value than the vehicle dynamic indicators. Taking the effects of the bridge pier settlement, the vehicle load, the prestress effect, and the self-weight into consideration, the pier settlement safe value for the high-speed railway lines with the CRTS II slab track is 11.5 mm.


2021 ◽  
Vol 11 (8) ◽  
pp. 3558
Author(s):  
Linh Vu ◽  
Dong Doo Jang ◽  
Yun Suk Kang

Recently, precast slab tracks have been used widely in railway applications, especially in conventional urban railway lines. These types of tracks are rapidly constructed and limit interruptions to train operation. However, the problems of dynamic stability when the trains run on the discontinuous type of tracks must be seriously considered. This paper focuses on analyzing the train-track interaction in two types of tracks under the dynamic load by using the numerical analysis program (APATSI) to evaluate the structural response as well as the running safety to precisely understand the load transfer efficiency of precast slab track systems.


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