轮对等效锥度与车辆动态特性关系分析

为了分析轮对等效锥度对车辆动力学性能的影响,采用设计不同等效锥度磨耗型踏面和锥形踏面的方法,通过轮轨接触和车辆动力学计算,分析了等效锥度对车辆临界速度和曲线通过性能的影响.结果表明,车辆临界速度并不严格地与等效锥度平方根成反比,而是存在临界速度较高的小等效锥度区域,太小、太大的等效锥度均会导致临界速度迅速降低.等效锥度随轮对横移的增大而增大有利于提高曲线通过性能,并可缓解轮缘磨耗.因此,在轮对小幅横移时等效锥度可以取较小值,并随轮对横移量的增大而增大,可兼顾车辆临界速度与曲线通过性能的要求.     

后轮对独立回转新型转向架的曲线通过性能研究

利用力(矩)的平衡原理,分析了新型转向架曲线导向性能提高的机理.在文献[2]的基础上对最佳的一系纵向刚度布置的新型转向架和传统转向架车辆的曲线性能进行了仿真对比.研究结果表明新型转向架的曲线导向性能优于传统转向架.     

Analysis of the nonlinear dynamics of a 2–axle freight wagon in curves

This paper deals with the study of the nonlinear dynamic behaviour of 2-axle freight wagons in curves, considering the case of one single wagon (neglecting inter-car coupling forces) and of multiple wagons interacting through the buffers and the couplers. A multi-body model of a single wagon and of a three-car assembly is introduced, paying particular attention to the nonlinear and nonsmooth modelling of the suspensions and of the inter-car coupling elements. Using this model, a numerical analysis of the steady-state solution reached after the negotiation of curve transition is presented and bifurcations are identified for some particular values of the curve radius. For the single car case, it is shown that depending on the curve radius and the vehicle speed the carbody may experience severe periodic oscillations at speeds lying in the operating range of the vehicle. For the car-assembly case, it is shown that the coupling forces exchanged by the wagons significantly affect their dynamics in a curve, reducing the amplitude of vibration.     

重载货车迫导向径向转向架的设计

针对国内货运快速重载化发展所产生的车辆系统动力学问题,基于自导向径向转向架和迫导向径向转向架的设计原理,参照Scheffel自导向径向转向架,在转K6型交叉支撑转向架的基础上,对自导向径向转向架和迫导向径向转向架进行结构设计,并将这三种低动力转向架的曲线通过性能进行对比分析.结果表明,所设计的迫导向径向转向架相比自导向径向转向架和转K6型交叉支撑转向架在轮对冲角、轮轨横向力、脱轨系数、整车磨耗功率方面具有性能优越性,并且具有良好的蛇行稳定性,说明对迫导向径向转向架的结构设计是合理的.     

最佳轮轨匹配评价5原则

为了更好地研究轨道车辆动力学性能,在四种典型踏面（S1002、S1002G、XP55和LMA）轮轨匹配特性对比分析基础上,提出了最佳轮轨匹配评价5原则.与锥形踏面相比,曲线型面踏面赋予了轮轨匹配新的内涵,如等效锥度是反映轮轨横向力对运行质量影响的等效平均参数.在充分考虑了轮背距、轨底坡和轮径等轮轨参数影响的条件下,四种踏面的轮轨匹配表明,LMA和XP55可以满足高速车辆的稳定性和轮轨低动力作用的要求,但是,在踏面磨耗方面尚存在不足：LMA的轮缘根部以单一曲率圆弧作为过渡段且存在接触综合曲率＂突变＂,有可能形成集中磨耗;而XP55在小半径R≤500 m曲线通过时牵引系数较高,有可能造成车轮打滑和轮缘接触.由于在轨道窗口内具有锥形踏面匹配特征,因而S1002被看作磨耗敏感型踏面.S1002G的改进设计意图是在轮背距1 353 mm和轨底坡1∶20的轮轨条件下进一步提高原S1002踏面的轮轨对中性能和导向性能,但需要利用抗蛇形减振器进一步提高其横向稳定性.根据国外轻轨车辆的运营经验,基于轮轨磨耗研究的＂通用＂轮轨型面方法是非常值得借鉴和研究的.     

Comparative stability of bogie vehicles with passive and active guidance as influenced by friction and traction

The stability of four bogie configurations is considered for a range of friction coefficients and traction ratios. The basis of comparison is the vehicle with conventional solid-axle railway wheelsets mounted in bogies with relatively stiff plan-view suspension. As improved performance of the wheelset in guidance can be achieved with various forms of passive and active guidance, bogies with yaw relaxation, with conventional wheelsets and active stabilisation and with independent wheels and active guidance are considered. Stability of each of these configurations is studied using a full nonlinear solution of the equations of motion. It is shown that the stability of the passive bogie configurations is very robust in the presence of traction and braking and variations of friction and that this is also true for an actively guided bogie with independent wheels. However, for a bogie with conventional wheelsets and active stabilisation, creep saturation effects can reduce stability significantly.     

Fundamentals of vehicle–track coupled dynamics

This paper presents a framework to investigate the dynamics of overall vehicle–track systems with emphasis on theoretical modelling, numerical simulation and experimental validation. A three-dimensional vehicle–track coupled dynamics model is developed in which a typical railway passenger vehicle is modelled as a 35-degree-of-freedom multi-body system. A traditional ballasted track is modelled as two parallel continuous beams supported by a discrete-elastic foundation of three layers with sleepers and ballasts included. The non-ballasted slab track is modelled as two parallel continuous beams supported by a series of elastic rectangle plates on a viscoelastic foundation. The vehicle subsystem and the track subsystem are coupled through a wheel–rail spatial coupling model that considers rail vibrations in vertical, lateral and torsional directions. Random track irregularities expressed by track spectra are considered as system excitations by means of a time–frequency transformation technique. A fast explicit integration method is applied to solve the large nonlinear equations of motion of the system in the time domain. A computer program named TTISIM is developed to predict the vertical and lateral dynamic responses of the vehicle–track coupled system. The theoretical model is validated by full-scale field experiments, including the speed-up test on the Beijing–Qinhuangdao line and the high-speed running test on the Qinhuangdao–Shenyang line. Differences in the dynamic responses analysed by the vehicle–track coupled dynamics and by the classical vehicle dynamics are ascertained in the case of vehicles passing through curved tracks.     

高速铁道车辆稳态曲线通过研究

高速铁道车辆通过曲线时,轮机作用力、抢重减载率、脱轨系数均较低 速车辆同类值高,同时轮轨磨耗加剧。本文村稳态曲线通过的研究,从 理论上给出了高速铁道车辆所能通过的最小曲线的半径、所需超高等, 同时给出了付车辆曲线通过性能有影响的几个参数,以确定最佳的悬挂 参数和结构参数。      

橡胶轮转向架对车辆曲线通过性能的影响

重点分析了橡胶轮转向架车辆的特色技术对车辆曲线通过性能的影响,分析对象包括承重与导向橡胶轮胎、单向止推轴承和空气弹簧,分析内容侧重于承重与导向橡胶轮胎和空气弹簧漏气以及单向止推轴承处于非正常工作状态对曲线通过安全性和轮胎磨耗的影响。     

主副构架铰接的主动径向转向架曲线通过性能研究

开发了一种主副构架弹性铰接的新型城市轨道交通车辆转向架,其轮对定位采用不对称悬挂,主构架上轮对纵向定位刚度小,副构架上轮对纵向定位刚度大。此新型转向架具有主动径向功能:转向架正向通过曲线时,作动器动作使得副构架相对主构架产生弯折角,并带动其轮对处于径向位置,提高了曲线通过性能;转向架反向通过曲线时,利用主构架轮对自身的导向特性实现曲线通过。此种转向架的曲线通过性能大大提高,并同时兼顾了其直线运行稳定性。