3D brush model to predict longitudinal tyre characteristics

A 3D tyre brush model, which aims to predict the longitudinal tyre characteristic under steady-state conditions by modelling the occurring physical effects in the tyre–road contact patch, is presented. The model includes an analytical method to describe the tyre footprint geometry, the pressure distribution, the slip due to the lateral tyre contour, the slip due to braking or traction and the longitudinal as well as the lateral shear stresses on a flattened tyre. The presented development tool offers a method to investigate different rubber friction data (caused by different tread compounds and/or surface textures) and to analyse its influence on longitudinal tyre characteristics. The tyre design is fixed (same casing, dimension and pattern). The results include the shear stresses as well as the different sliding velocities in the contact patch for different slip conditions. The model was developed for a standard summer pattern design and a standard tyre dimension (205/55R16). It can also be adapted to other tread designs and tyre dimensions. To offer a good comparability between model results and test bench measurements, the surface curvature of an internal test rig is considered.     

A model for prediction of the transient rolling resistance of tyres based on inner-liner temperatures

Measurements of rolling resistance in thermal equilibrium of a tyre, like measurements according to ISO 28580, do not allow statements about rolling resistances under other driving conditions. Such statements, however, are necessary to determine the energy consumption in driving cycles. Especially for the proper calculation of electric-vehicle remaining ranges and the selection of the respective driving strategies, the real amount of energy consumption is required. This paper presents a model approach, which by means of only one standardised rolling resistance measurement can be parameterised and, considering the present driving speed and tyre temperature, can predict the respective current rolling resistance.     

采用新控制和传动技术的汉堡地铁车辆

为了试验汉堡地铁今后车辆采用的新技术,将最近交货的17台DT4车辆装备了最新一代控制和传动技术,用MIRAC的控制技术系统取代以前DT4车辆应用的MICAS-S系统,变流器由GTO技术改为IGBT技术.新设计可以改造以前结构系列的DT4车辆.     

香港是内企的好试场

去年首十个月，本港新股上市集资额已超过2．580亿港元，较前年同期大增76％。去年全球25大招股活动中，本港已独占其六。当中包括创了全球集资额纪录（279亿美元）的工商银行上市。目前为止，连同第五位的中国银行和第八位的建设银行．本港已在全球十大招股活动占三个席位。