Influence of AC system design on the realisation of tractive efforts by high adhesion locomotives

The main task for heavy haul railway operators is to reduce the cost of exported minerals and enhance the long-term viability of rail transport operations through increasing productivity by running longer and heavier trains. The common opinion is that this is achievable by means of implementation of high adhesion locomotives with advanced AC traction technologies. Modern AC high adhesion locomotives are very complex mechatronic systems and can be designed with two alternative traction topologies of either bogie or individual axle controls. This paper describes a modelling approach for these two types of AC traction systems with the application of an advanced co-simulation methodology, where an electrical system and a traction algorithm are modelled in Matlab/Simulink, and a mechanical system is modelled in a multibody software package. Although the paper concentrates on the analysis of the functioning for these two types of traction control systems, the choice of reference slip values also has an influence on the performance of both systems. All these design variations and issues have been simulated for various adhesion conditions at the wheel–rail interface and their influence on the high traction performance of a locomotive equipped with two three-axle bogies has been discussed.     

Noise,vibration, harshness model of a rotating tyre

ABSTRACT

The tyre plays a fundamental role in the generation of acoustically perceptible driving noise and vibrations inside the vehicle. An essential part of these vibrations is induced by the road excitation and transferred via the tyre into the vehicle. There are two basic ways to study noise, vibration, harshness (NVH) behaviour: Simulations in time and frequency domains. Modelling the tyre transfer behaviour in frequency domain requires special attention to the rotation of the tyre. This paper shows the approach taken by the authors to include the transfer behaviour in the frequency range up to 250?Hz from geometric road excitations to resulting spindle forces in frequency domain. This paper validates the derived NVH tyre model by comparison with appropriate transient simulations of the base transient model.     

欧洲规范中列车脱轨撞击结构设计的研究

为了研究适用于我国情况的高速铁路列车脱轨撞击临近结构的碰撞机理和设计方法,分析了欧洲规范EN1991-1-7中列车脱轨撞击临近结构条款制定所依据的英国铁路集团标准GC/RT5112和国际铁路联盟规程UIC777-2R,包括轨道两侧危险区域、作用荷载、预防措施等,介绍了欧洲规范EN1991-1-7中偶然荷载的设计策略,评述了对欧洲规范产生重要影响的列车脱轨撞击结构作用机理的主要研究成果.研究表明:欧洲规范关于列车脱轨结构撞击临近结构的研究方法和设计策略值得借鉴,但我国高铁站房结构特点、运行速度、道床做法、车辆编组等与欧洲均不同,需要根据我国的情况研究列车脱轨撞击临近结构问题.      

高精度管片的制作

一般情况下不会对生产隧道衬砌管片的管模精度提出要求,典型的管片衬砌隧道工程招标书中通常只给出成品管片尺寸方面的精度要求,在有些情况下只给出两环试拼装的精度要求.现在对管片尺寸精度的要求越来越高,这就需要一个快速、精密、可靠的方法来测定这些尺寸值.