Experimental study of a honeycomb energy-absorbing device for high-speed trains

Aluminium honeycomb is a light weight, thin-walled material with a typical multi-cellular construction and a good strength-to-weight ratio. Therefore, aluminium honeycomb can be used as an energy-absorbing device for high-speed trains. Due to its large mass and high operating speed, a high-speed train can generate large impact energy. Thus, an energy-absorbing device with a greater energy absorption capability must be designed for high-speed trains. To reduce the aerodynamic drag, the cross-sectional area of a high-speed train is limited. Therefore, a honeycomb energy-absorbing device should be designed in such a way that it is longer than the traditional energy-absorbing devices; however, this may lead to bending, destruction and uncontrollable deformation of the honeycomb; these factors are not conducive for energy absorption. In this paper, a sleeve structure was designed for high-speed trains, and a crash experiment of the energy-absorbing structure showed that the bending and destruction of the honeycomb energy-absorbing device are effectively suppressed compared with the ordinary honeycomb energy-absorbing structure. Moreover, the fluctuation of the crash force was smaller and the crash force is more stable than the traditional thin-walled energy-absorbing structure. Therefore, the deformation instability problem of the ordinary honeycomb energy-absorbing structure and the crash force fluctuation problem of the traditional thin-walled energy-absorbing structure can be solved. Then, a crash experiment and simulation involving a high-speed train with improved honeycomb energy-absorbing device was carried out, and the results showed that the deformation of the end of the train body was stable and controllable, and the train body deceleration satisfied the collision standard EN15227.

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Design of large-scale streamlined head cars of high-speed trains and aerodynamic drag calculation

Archives of Transport ◽

10.5604/01.3001.0010.6164 ◽

2017 ◽

Vol 44 (4) ◽

pp. 89-97 ◽

Cited By ~ 2

Author(s):

Zhenfeng Wu ◽

Enyu Yang ◽

Wangcai Ding

Keyword(s):

High Speed ◽

Large Scale ◽

Production Control ◽

Aerodynamic Drag ◽

Design Method ◽

Control Point ◽

Surface Characteristics ◽

High Speed Train ◽

Research Subjects ◽

High Speed Trains

Aerodynamic drag plays an important role in high-speed trains, and how to reduce the aerodynamic drag is one of the most important research subjects related to modern railway systems. This paper investigates a design method for large-scale streamlined head cars of high-speed trains by adopting NURBS theory according to the outer surface characteristics of trains. This method first created the main control lines of the driver cab by inputting control point coordinates; then, auxiliary control lines were added to the main ones. Finally, the reticular region formed by the main control lines and auxiliary ones were filled. The head car was assembled with the driver cab and sightseeing car in a virtual environment. The numerical simulation of train flow field was completed through definition of geometric models, boundary conditions, and space discretization. The calculation results show that the aerodynamic drag of the high-speed train with large-scale streamlined head car decreases by approximately 49.3% within the 50-300 km/h speed range compared with that of the quasi-streamlined high-speed train. This study reveals that the high-speed train with large-scale streamlined head car could achieve the purpose of reducing running aerodynamic drag and saving energy, and aims to provide technical support for the subsequent process design and production control of high-speed train head cars.

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Improving Collision Energy Absorption In High Speed Train By Using Thin Walled Tubes

International Journal of Railway ◽

10.7782/ijr.2013.6.3.085 ◽

2013 ◽

Vol 6 (3) ◽

pp. 85-89 ◽

Cited By ~ 2

Author(s):

Ehsan Salimi ◽

Habib Molatefi ◽

MohammadAli Rezvani ◽

Erfan Shahsavari

Keyword(s):

Energy Absorption ◽

High Speed ◽

Collision Energy ◽

High Speed Train ◽

Thin Walled

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Optimization of the high-speed train head using the radial basis function morphing method

Proceedings of the Institution of Mechanical Engineers Part F Journal of Rail and Rapid Transit ◽

10.1177/0954409719841518 ◽

2019 ◽

Vol 234 (1) ◽

pp. 96-107

Author(s):

Rui Li ◽

Ping Xu ◽

Shuguang Yao

Keyword(s):

High Speed ◽

Aerodynamic Drag ◽

Shape Parameters ◽

High Speed Train ◽

Aerodynamic Optimization ◽

Resistance Response ◽

Surface Models ◽

High Speed Trains ◽

Window Region ◽

Aerodynamic Drag Reduction

Aerodynamic drag reduction is one of the most important issues in the development of high-speed trains. This study focused on the aerodynamic optimization of the train by modifying the shape of the head car and tail car. Three shape parameters were studied in this paper: the angle of cab-window, nose-length, and nose-width of the train. The effects of shape parameters on the aerodynamic drag coefficients of the head car and tail car were discussed, respectively. It can be concluded that the flat surface of the window region, long and sharp nose are the distinguishing characters of a high-speed train with low resistance. Response surface models of the shape parameters and the aerodynamic drag of the head car and tail car were obtained, respectively. Based on these models, an aerodynamic optimization was performed to achieve the optimal shape. As a result, the total aerodynamic drag of the optimal train decreased by 2.05% compared with the original value.

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The Effect of Geometrical Non-Linearity on the Crashworthiness of Thin-Walled Conical Energy-Absorbers

Materials ◽

10.3390/ma13214857 ◽

2020 ◽

Vol 13 (21) ◽

pp. 4857

Author(s):

Michal Rogala ◽

Jakub Gajewski ◽

Miroslaw Ferdynus

Keyword(s):

Energy Absorption ◽

Wall Thickness ◽

Absorption Capacity ◽

Energy Absorption Capacity ◽

Cross Sectional ◽

Variable Wall Thickness ◽

Thin Walled ◽

Variable Wall ◽

Energy Absorbers ◽

Energy Absorbing

Crashworthiness of conical shells is known to depend on various factors. This study sets out to determine the extent to which the cross-sectional diameter contributes to their energy-absorbing properties. The object of the study was thin-walled aluminium tubes varying in upper diameter and wall thickness. The components were subjected to dynamic axial crushing kinetic energy equal to 1700 J. The numerical analysis was performed using Abaqus 6.14 software. The specific aim of the study was to determine the extent to which variable wall thickness affects the energy absorption capacity of the components under study. From the simulations, we have managed to establish a relationship between total energy absorption capacity and wall thickness. The results from the conducted analyses and the purpose-specific neural networks could provide the base for the future methodology for forecasting and optimisation of energy-absorbing systems.

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Structure Clearance Design in Wind Tunnel Tests with Implications for Aerodynamic Drag of High-Speed Trains

10.21203/rs.3.rs-1073613/v1 ◽

2021 ◽

Author(s):

Zhixiang Huang ◽

Hanjie Huang ◽

Weiping Zeng ◽

Li Chen ◽

Renyu Zhu

Keyword(s):

Reynolds Number ◽

Wind Tunnel ◽

Drag Coefficient ◽

Distribution Pattern ◽

High Speed ◽

Aerodynamic Drag ◽

High Speed Train ◽

Wind Tunnel Tests ◽

High Speed Trains

Abstract The influences of vestibule diaphragm gap, wheel-rail clearance, and strut-plate gap on the aerodynamic drag of a 1/8th-scale high-speed train model were investigated in an 8 m×6 m wind tunnel. The Reynolds number was set to 2.2×106 based on train height. It was found that the variation of the vestibule diaphragm gap changed the aerodynamic drag distribution pattern of each car; the drag coefficient of the head and middle cars might change as high as 45%; however, the change in the drag coefficient of the total train was very small. The effects of the strut-plate gap on the aerodynamic drag of each car and the total train were small. The effect of the wheel-rail clearance on the drag of the head car was not significant. It was suggested that the vestibule diaphragm gap, strut-plate gap and wheel-rail clearance of the 1:8 scale high-speed train model should not be greater than 11, 10, and 9 mm, respectively.

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Comparative study on the use of acoustic emission and vibration analyses for the bearing fault diagnosis of high-speed trains

Structural Health Monitoring ◽

10.1177/14759217211036025 ◽

2021 ◽

pp. 147592172110360

Author(s):

Dongming Hou ◽

Hongyuan Qi ◽

Honglin Luo ◽

Cuiping Wang ◽

Jiangtian Yang

Keyword(s):

Acoustic Emission ◽

Fault Diagnosis ◽

High Speed ◽

High Speed Train ◽

Signal Attenuation ◽

Transmission Path ◽

Bearing Fault Diagnosis ◽

Operation Conditions ◽

Fault Features ◽

High Speed Trains

A wheel set bearing is an important supporting component of a high-speed train. Its quality and performance directly determine the overall safety of the train. Therefore, monitoring a wheel set bearing’s conditions for an early fault diagnosis is vital to ensure the safe operation of high-speed trains. However, the collected signals are often contaminated by environmental noise, transmission path, and signal attenuation because of the complexity of high-speed train systems and poor operation conditions, making it difficult to extract the early fault features of the wheel set bearing accurately. Vibration monitoring is most widely used for bearing fault diagnosis, with the acoustic emission (AE) technology emerging as a powerful tool. This article reports a comparison between vibration and AE technology in terms of their applicability for diagnosing naturally degraded wheel set bearings. In addition, a novel fault diagnosis method based on the optimized maximum second-order cyclostationarity blind deconvolution (CYCBD) and chirp Z-transform (CZT) is proposed to diagnose early composite fault defects in a wheel set bearing. The optimization CYCBD is adopted to enhance the fault-induced impact response and eliminate the interference of environmental noise, transmission path, and signal attenuation. CZT is used to improve the frequency resolution and match the fault features accurately under a limited data length condition. Moreover, the efficiency of the proposed method is verified by the simulated bearing signal and the real datasets. The results show that the proposed method is effective in the detection of wheel set bearing faults compared with the minimum entropy deconvolution (MED) and maximum correlated kurtosis deconvolution (MCKD) methods. This research is also the first to compare the effectiveness of applying AE and vibration technologies to diagnose a naturally degraded high-speed train bearing, particularly close to actual line operation conditions.

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Design of Optimization Platform for Energy Absorption Structure of High Speed Train

2019 IEEE 23rd International Conference on Computer Supported Cooperative Work in Design (CSCWD) ◽

10.1109/cscwd.2019.8791887 ◽

2019 ◽

Author(s):

Xiaojun Zheng ◽

Jiang Zhong ◽

Yanbin Sun ◽

Yanjun Shi ◽

Zhizheng Xu ◽

...

Keyword(s):

Energy Absorption ◽

High Speed ◽

High Speed Train

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A Study on the Energy-Harvesting Device with a Magnetic Spring for Improved Durability in High-Speed Trains

Micromachines ◽

10.3390/mi12070830 ◽

2021 ◽

Vol 12 (7) ◽

pp. 830

Author(s):

Jaehoon Kim

Keyword(s):

Energy Harvesting ◽

High Speed ◽

Permanent Magnets ◽

Critical Issue ◽

Sensor Nodes ◽

High Speed Train ◽

Vibration Energy Harvesting ◽

Magnetic Spring ◽

High Speed Trains ◽

Energy Harvesting Devices

Durability is a critical issue concerning energy-harvesting devices. Despite the energy-harvesting device’s excellent performance, moving components, such as the metal spring, can be damaged during operation. To solve the durability problem of the metal spring in a vibration-energy-harvesting (VEH) device, this study applied a non-contact magnetic spring to a VEH device using the repulsive force of permanent magnets. A laboratory experiment was conducted to determine the potential energy-harvesting power using the magnetic spring VEH device. In addition, the characteristics of the generated power were studied using the magnetic spring VEH device in a high-speed train traveling at 300 km/h. Through the high-speed train experiment, the power generated by both the metal spring VEH device and magnetic spring VEH device was measured, and the performance characteristics required for a power source for wireless sensor nodes in high-speed trains are discussed.

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