A direct method-based strength evaluation of the cast aluminum beam used in a high-speed train

Author(s):  
Songhua Huang ◽  
Yugong Xu ◽  
Alexander Bezold ◽  
Lele Zhang ◽  
Geng Chen ◽  
...  

In this paper, the authors elaborate how numerical techniques developed from the direct method can be used to predict the load-bearing capacity of the aluminum casting beam structure which is presently used in the Chinese high-speed train CRH5A. The numerical method introduced in this paper is formulated based on the Melan's static theorem; thus, it determines the strength of the cast aluminum beam under both monotonic and cyclic loads without following the entire load profile. In addition to constructing the plastic and shakedown limits of the component, the proposed approach is also employed to study how stiffeners' thickness on the key areas influences the feasible load domains. Based on the intensive sensitivity analysis, an optimal thickness has been determined which gives the highest strength-to-weight ratio. To this end, the paper confirms that the direct method is a viable means for designing structures used in the rolling stock.

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Weiyuan Dou ◽  
Lele Zhang ◽  
Haifeng Chang ◽  
Haifeng Zhang ◽  
Changqing Liu

AbstractThe cast aluminum beam is a key structure for carrying the body-hung traction motor of a high-speed train; its fatigue property is fundamental for predicting the residual life and service mileage of the structure. To characterize the structural fatigue property, a finite element-based method is developed to compute the stress concentration factor, which is used to obtain the structural fatigue strength reduction factors. A full-scale fatigue test on the cast aluminum beam is designed and implemented for up to ten million cycles, and the corresponding finite element model of the beam is validated using the measured data of the gauges. The results show that the maximum stress concentration occurs at the fillet of the supporting seat, where the structural fatigue strength reduction factor is 2.45 and the calculated fatigue limit is 35.4 MPa. Moreover, no surface cracks are detected using the liquid penetrant test. Both the experimental and simulation results indicate that the cast aluminum beam can satisfy the service life requirements under the designed loading conditions.


2012 ◽  
Vol 586 ◽  
pp. 269-273
Author(s):  
Chul Su Kim ◽  
Gil Hyun Kang

To assure the safety of the power bogies for train, it is important to perform the durability analysis of reduction gear considering a variation of velocity and traction motor capability. In this study, two types of applied load histories were constructed from driving histories considering the tractive effort and the train running curves by using dynamic analysis software (MSC.ADAMS). Moreover, this study was performed by evaluating fatigue damage of the reduction gears for rolling stock using durability analysis software (MSC.FATIGUE). The finite element model for evaluating the carburizing effect on the gear surface was used for predicting the fatigue life of the gears. The results showed that the fatigue life of the reduction gear would decrease with an increasing numbers of stops at station.


Author(s):  
B Diedrichs

This work addresses crosswind stability exemplified for the German Railway Deutsche Bahn AG high-speed train ICE 2. The scope of the work is to describe the flow by means of computational fluid dynamics past the leading two cars of the train for yaw angles in the range 12.2–40.0°. Three track formations are utilized. The basic results are the set of independent aerodynamic coefficients for the lead and subsequent cars. The results are to some extent compared with experimental data for ICE 2 and also with data obtained for the Swedish high-speed train X2000. A numerical sensitivity study is undertaken to quantify differences in the above results dependent on the grid density and quality, turbulence model, numerical scheme, location of inlet and outlet boundaries, turbulence intensity and flow simulation software.


Author(s):  
Jieyi Deng ◽  
Guoqing Jing ◽  
Xiang Liu

Safety is a top priority for the development of worldwide high-speed rail systems. Ballast flying is a particular safety concern when a high-speed train is traveling above a certain speed on the ballasted track. Displaced ballast particles from the track may cause damages to rolling stock, as well as the track infrastructure and wayside structures close to the sides of way. The objective of this research is to develop a probabilistic modeling framework to estimate the probability of ballast flight on specific segments or routes, accounting for several principal risk factors. Based on the probabilistic assessment, we propose a methodology to quantify the probability of flying ballast under certain scenarios. The methodology can be further developed, ultimately enabling a normative risk assessment for flying ballast risk management.


2021 ◽  
Vol 349 ◽  
pp. 04011
Author(s):  
Radek Doubrava ◽  
Martin Oberthor ◽  
Petr Bělský ◽  
Bohuslav Cabrnoch

Bird strikes are an important phenomenon that must be taken into consideration when designing aircraft. A bird impact experiment provides a direct method to examine the bird strike resistance. However, the design of the aircraft structures usually involves many iterations of design-manufacturing-test and conducting bird impact experiments is not only time consuming but also costly. The aim of this work is to show the application of test verified numerical simulation for the design of composite cowlings of the high-speed helicopter.


Author(s):  
Benhuai Li ◽  
Zhaijun Lu ◽  
Kaibo Yan ◽  
Sisi Lu ◽  
Lingxiang Kong ◽  
...  

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.


2014 ◽  
Vol 2014 ◽  
pp. 1-17 ◽  
Author(s):  
Sergio Avila-Sanchez ◽  
Santiago Pindado ◽  
Oscar Lopez-Garcia ◽  
Angel Sanz-Andres

Wind-flow pattern over embankments involves an overexposure of the rolling stock travelling on them to wind loads. Windbreaks are a common solution for changing the flow characteristic in order to decrease unwanted effects induced by the presence of cross-wind. The shelter effectiveness of a set of windbreaks placed over a railway twin-track embankment is experimentally analysed. A set of two-dimensional wind tunnel tests are undertaken and results corresponding to pressure tap measurements over a section of a typical high-speed train are herein presented. The results indicate that even small-height windbreaks provide sheltering effects to the vehicles. Also, eaves located at the windbreak tips seem to improve their sheltering effect.


2020 ◽  
Vol 31 (20) ◽  
pp. 2362-2377 ◽  
Author(s):  
Jaehoon Kim

An electromagnetic energy harvesting device was studied based on the design parameters of an energy harvesting device for the power source of wireless sensors node on the rolling stock. The characteristics of the generated power by the energy harvesting device were tested using the laboratory equipment and a rolling stock (a high-speed train). First, a cantilever beam energy harvesting device, which allows for easy adjustment of the length according to the frequency and the power according to the cantilever beam materials, was researched. In addition, the new design for a practical resonant energy harvesting device for the railroad system was performed. To realize the performance of the practical resonant energy harvesting device, the generated power characteristics of the energy harvesting device were tested according to the moving displacement, the number of coil turns, and the initial coil displacement between the coil and magnet. The evaluation of the performance of the manufactured resonant energy harvesting device for the railroad system, which the parameters were determined based on the test results, was conducted under real driving conditions in the high-speed train, which was traveling at 300 km/h. Finally, this study analyzed whether the power generated could be applied to the wireless sensor nodes for the railroad system.


2015 ◽  
Vol 20 (2) ◽  
pp. 283-297 ◽  
Author(s):  
K. Grębowski ◽  
M. Zielińska

Abstract The article presents the dynamic analysis of the historic railway bridge in Tczew as an example of the usefulness of such type of bridge for high-speed trains. The model of the bridge and the simulation of rolling stock passage was performed in SOFISTIK program. The scope of work includes experimental studies, the solution of the problem concerning the correct solution features of the dynamic model which takes into account the dependencies between the bridge, track and rolling - stock (RBT). The verification of the model was performed by comparing the results obtained on site during the passage of ET-22 locomotive and twenty (20) open goods wagons with the results obtained in the program for the identical type of rolling stock used to the simulation Pendolino train. Then, after the verification, the simulation of high-speed train passage was performed. The speed of the train passage varied from 150 [km/h] to the max. possible speed of 250 [km/h] which PENDOLINO train, approved for the simulation, may reach. Under the analysis of obtained results it was possible to define the conditions for adjusting the historic bridge to high-speed train passage.


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