The results of the pantograph–catenary interaction benchmark

This paper describes the results of a voluntary benchmark initiative concerning the simulation of pantograph–catenary interaction, which was proposed and coordinated by Politecnico di Milano and participated by 10 research institutions established in 9 different countries across Europe and Asia. The aims of the benchmark are to assess the dispersion of results on the same simulation study cases, to demonstrate the accuracy of numerical methodologies and simulation models and to identify the best suited modelling approaches to study pantograph–catenary interaction. One static and three dynamic simulation cases were defined for a non-existing but realistic high-speed pantograph–catenary couple. These cases were run using 10 of the major simulation codes presently in use for the study of pantograph–catenary interaction, and the results are presented and critically discussed here. All input data required to run the study cases are also provided, allowing the use of this benchmark as a term of comparison for other simulation codes.     

Nonlinear analysis of wind-induced vibration of high-speed railway catenary and its influence on pantograph–catenary interaction

The wind-induced vibration of the high-speed catenary and the dynamic behaviour of the pantograph–catenary under stochastic wind field are firstly analysed. The catenary model is established based on nonlinear cable and truss elements, which can fully describe the nonlinearity of each wire and the initial configuration. The model of the aerodynamic forces acting on the messenger/contact wire is deduced by considering the effect of the vertical and horizontal fluctuating winds. The vertical and horizontal fluctuating winds are simulated by employing the Davenport and Panofsky spectrums, respectively. The aerodynamic coefficients of the contact/messenger wire are calculated through computational fluid dynamics. The wind-induced vibration response of catenary is analysed with different wind speeds and angles. Its frequency-domain characteristics are discussed using Auto Regression model. Finally, a pantograph model is introduced and the contact force of the pantograph–catenary under stochastic wind is studied. The results show that both the wind speed and the attack angle exert a significant effect on the wind-induced vibration. The existence of the groove on the contact wire cross-section leads to a significant change of the aerodynamic coefficient, which affects largely the aerodynamic forces applied on the catenary wires, as well as the vibration response. The vibration frequency with high spectral power mainly concentrates on the predominant frequency of the fluctuating wind and the natural frequency of catenary. The increase in the wind speed results in a significant deterioration of the current collection. The numerical example shows that a relatively stable current collection can be ensured when the wind flows at the relatively horizontal direction.     

Variation in predicting pantograph–catenary interaction contact forces,numerical simulations and field measurements

The contact force between the pantograph and the contact wire ensures energy transfer between the two. Too small of a force leads to arching and unstable energy transfer, while too large of a force leads to unnecessary wear on both parts. Thus, obtaining the correct contact force is important for both field measurements and estimates using numerical analysis. The field contact force time series is derived from measurements performed by a self-propelled diagnostic vehicle containing overhead line recording equipment. The measurements are not sampled at the actual contact surface of the interaction but by force transducers beneath the collector strips. Methods exist for obtaining more realistic measurements by adding inertia and aerodynamic effects to the measurements. The variation in predicting the pantograph–catenary interaction contact force is studied in this paper by evaluating the effect of the force sampling location and the effects of signal processing such as filtering. A numerical model validated by field measurements is used to study these effects. First, this paper shows that the numerical model can reproduce a train passage with high accuracy. Second, this study introduces three different options for contact force predictions from numerical simulations. Third, this paper demonstrates that the standard deviation and the maximum and minimum values of the contact force are sensitive to a low-pass filter. For a specific case, an 80?Hz cut-off frequency is compared to a 20?Hz cut-off frequency, as required by EN 50317:2012; the results show an 11% increase in standard deviation, a 36% increase in the maximum value and a 19% decrease in the minimum value.     

Program for catenary–pantograph analysis,PrOSA statement of methods and validation according EN 50318

DB Systemtechnik is a high-performing, customer-driven service provider that, as well as authoritatively serving the Deutsche Bahn Group by dint of its specialist knowledge is also increasingly active on the global railway market. Development and testing of pantograph models and catenary systems have been part of the company's essential activity fields from the beginning. Therefore, an efficient and high-performing simulation tool is indispensable. That is why DB Systemtechnik spent high efforts to develop the program PrOSA in cooperation with the Heinz–Nixdorf–Institut (HNI) of the university Paderborn to simulate the interaction of pantograph and catenary. This article gives an overview of the most relevant properties of PrOSA. Furthermore, it is described how the benchmark requirements were implemented and processed.     

Facing the Challenge from WTO, Creating the Future of the Auto Industry

Editor's note: With a joint expectation of governments and common publics, China is speeding up to enter into the World Trade Organization and may be a member of WTO family soon. The concerns on the China's accession to WTO are what kinds of deep impacts will be brought on the China Auto Industry. Therefore, from now on, here's a series of articles collected to discuss that, covering whole auto industry, car industry, auto market, as well as after-market, etc. Meanwhile, I am grateful for any responses on this issue at your convenient time.     

Guidelines for the Development of the Auto Industry

Ⅰ. Cars The emphasis of this sector must be on developing economy cars which meet the demands of safety, energy conservation, emission regulations and individual use, and further raising the share in the total auto production. Environmentally-friendly cars for use as taxis should also be developed. By the end of the Tenth Five-Year-Plan period, gasoline     

On the discount wars in the first half and an analysis in the second half

1. Remarks on the price wars in the first half of 2007. 1.1 Broad scope. Almost all models from all makers were involved in the wars, including some high-end cars which have been hardly found in the past;     

Changes in the investment and the setup of production and sales in the auto industry

In 2002, the total investment in fixed assets of the auto industry was over 300 billion yuan. But the problems of investment scattering and insufficient R & D capabilities have not been resolved, which will restrain the healthy and orderly development of the auto industry.     

Who were the winners in the 2006 market?

Production and sales in China’s auto industry in 2006 exceeded 7 million units, both 23 percent up over the previous year. Compared with other world markets, all Chinese auto makers are winners. The growth rate of passenger cars is much higher than that …     

Auto makers are preparing for the slow-down of the economy

Export, investment and consumption are considered the three legs of the rapid growth of China’s economy. However, an analysis over the first 5 months shows that all of them are facing difficulties. The global economy, after enduring the fast growth in last year, is slowing down, which has resulted in the retarding of world trade and emerging of trade protectionism. China, which relies heavily on the export over the recent years, is now repeatedly the focus of trade disputes. The over investm…     

Next to nothing: the effect of the price wars

The sales statistics from January to May showed that the growth rate of wholepassenger vehicle sector is dropping. During the first half of 2004, a number of car makersreduced their prices to maintain market share, including GM and VW. It is calculated thatthe two VW joint ventures will make billion yuan less profit. Insiders point out that, although no one knows who will be next, one thing is certain:driven by the reduction of the Big Three, others will follow from June and it may inv…     

A Brief Analysis of the Impact of the Macro Economy on the Heavy Truck Market in 2005

Over the past two decades, China’s heavy truck market has grown to 1.5 million trucks. From 1998 through 2004, the market was in booming. But in the next few years, the development pace will be slowed down, mainly due to the macro regulation and control. It is well known that China’s auto market has been dominated by government policies and the heavy truck segment is in particular no exception. It is reported that after the “car rush”, this year’s focus is heavy trucks. On top of the ca…     

An Analysis of the Motorcycle Industry during the Tenth-Five-Year-Plan Period

1 Demand forecast of the motorcycle market It is forecasted that the market demand formotorcycle will be 12 million-13 million units by 2005. Within a certain period of time in the future, the demand for motorcycles will assume a wild increase. The market competition will shift from mere price war to the product quality, cost, varieties (especially the environmentally friendly ones), brand and after-sales service. Over the past decade, a good part of medium and big cities as well as coastal opening areas have     

An Introduction to the Research into the “Management System of the Ex-Factory Certification of Motor Vehicle

TosupporttheimplementationofRoadTrafficSafetyActandfurtherregularizetheproduction,sales,registrationanduseofautomobiles,NDRCandtheMinistryofPublicSecurityjointlydecidetoenhancethemanagementovertheex-factorycertificationofdomestic-madeautomobiles.CATARCandTrafficManagementInstituteofMinistryofPublicSafetyhavebeenappointedtodotheresearchanddevelopmentjob.Theworkincludessettingthemanagerialrules,theunitedpatternandanti-piracydemands,thespecificationtableandthemanagementsoftwaresystem.1.R…     

Unwrap the Veil of the Best Men and the Media Best Impressed Cars in China''''s Auto Industry

Li Shufu Director of board of Geely Group Co., Ltd. Yang Rong Director of board of Huachen Group Hu Maoyuan President of Shanghai Automotive Industry (Group) Corporation Miao Wei General Manager of Dongfeng Motor Corporation Chen Hong General Manager of Shanghai General     

Images of the Year

前几期，本刊陆续转载了由ENR杂志评选出的2012年“施工照片竞赛”的前20名作品。近期整理了后面部分，竟发现不少丝毫不逊色于前者的惊艳之作，现摭拾若干，使其免遭遗珠之憾。     

An Analysis on the Segmented Car Market in the First Quarter

The first quarter saw nearly 860,000 cars sold, an up of 66.02 percent over the same period last year. Medium cars grew the fastest, reaching 370,000, an up of 84.21 percent year on year, followed by upper medium and compact cars, at 76.33 and 74.56 perce…     

A comprehensive conclusion of the passenger car market in the first half

The first half saw a booming vehicle market, echoing to the entire national economy. The total sales and production were 3.6303 and 3.5352 million respectively, up of 28.94 percent and 26.71 percent year on year. It was considered a new round rapid growth rate after that occurred in between 2002-03. However, the trend faced challenge beginning in June, due to repeated fuel price rising, expectations for new models and prices wars. Cars were among the soaring passenger vehicles, with productio…     

An Analysis and Forecast on the MPV Market in the First Quarter

Ⅰ The first quarter saw a total of 865,000 passenger vehicles was sold, including 41,300 MPVs, an up of 75.5 percent year on year. The market share of MPVs is 4.3 percent, 0.2 percentage points higher than in the sameperiod last year. It indicates the ca…     

An Analysis and Forecast on the SUV Market in the First Half

2005 saw a most toughest SUV market and some expect a huge reshuffle of the industry will occur in the following year. However, the market during the top 3 months reported marginal growth in terms of production and sales. The latest figures show that 19 S…