改善摆式列车的乘坐舒适度

介绍了日本为改善摆式车辆的乘坐舒适度而开发的新型倾摆控制系统.通过运行试验,确认了该系统在减少晕车发生率、改善乘坐舒适度方面取得的效果,并给出了新的乘坐舒适度评价方法.     

Utilization patterns of park and ride facilities among Kuala Lumpur commuters

A parking utilization survey was undertaken with the main objective of analyzing and comparing the daily workday utilization patterns of two main park and ride stations within the Kuala Lumpur conurbation. This study also aimed to gauge the level of usage of the park and ride facilities. The findings showed that the overall utilization pattern of the facilities was very high with a utilization rate of between 80 and 95%. The stations, however, recorded a contrasting accumulation pattern. The study further revealed that most of the rail-based suburban park and ride users were long term parkers. The results of this study are comparable to results of similar studies in Seoul, Calgary, Tyne and Wear and others. Since parking availability is an important factor that has influence on the behavior of a park and ride user, more accurate information relating to the supply and demand of the park and ride facility will assist in planning new transport infrastructure.

对汽车平顺性评价方法的探讨与建议

首先分析了现行国家标准GB4970-1996<汽车平顺性随机输入行驶试验方法>与国际上通行的人体振动评价标准ISO2631-1997的区别.通过道路试验测量了驾驶员坐垫、靠背和脚部的平移振动以及坐垫的旋转振动共lO个方向的振动.分析发现汽车中人体振动的峰值因子一般小于9;而按照GB4970和ISO2631的试验数据对比表明,GB4970在一定程度上低估了人体振动.分析各方向振动所占的比例发现,坐垫垂向振动、靠背前后振动和坐垫侧倾振动影响最大.最后提出了对汽车平顺性评价方法的建议.     

Roll and pitch independently tuned interconnected suspension: modelling and dynamic analysis

In this paper, a roll and pitch independently tuned hydraulically interconnected passive suspension is presented. Due to decoupling of vibration modes and the improved lateral and longitudinal stability, the stiffness of individual suspension spring can be reduced for improving ride comfort and road grip. A generalised 14 degree-of-freedom nonlinear vehicle model with anti-roll bars is established to investigate the vehicle ride and handling dynamic responses. The nonlinear fluidic model of the hydraulically interconnected suspension is developed and integrated with the full vehicle model to investigate the anti-roll and anti-pitch characteristics. Time domain analysis of the vehicle model with the proposed suspension is conducted under different road excitations and steering/braking manoeuvres. The dynamic responses are compared with conventional suspensions to demonstrate the potential of enhanced ride and handling performance. The results illustrate the model-decoupling property of the hydraulically interconnected system. The anti-roll and anti-pitch performance could be tuned independently by the interconnected systems. With the improved anti-roll and anti-pitch characteristics, the bounce stiffness and ride damping can be optimised for better ride comfort and tyre grip.     

Kinematic and dynamic analysis of a heavy truck with individual front suspension

The main focus of this work is on the characteristics of a commercial vehicle with individual front suspension (IFS). Both kinematic and dynamic properties of the vehicle are investigated through simulations and analytical expressions. Moreover, employing the model of the tractor semitrailer combination, the study presents the results of comparison between the trucks with IFS and rigid front axle with respect to comfort and handling. This is done by analysing the responses of the vehicles to different road and steering inputs. The obtained results show enhanced comfort and steering feeling for the truck with IFS.     

越野车复合型悬架平顺性的研究

为解决越野车在复杂路面行驶过程中平顺性较差的问题,本文中在某型越野车原悬架系统上加装空气弹簧,形成新型复合型悬架结构.首先为探究越野车悬架系统的振动机理,通过对越野车空气弹簧和原悬架系统进行理想化结构分析,构建出了空气弹簧与螺旋弹簧相并联的复合型悬架系统模型;然后针对越野车行驶要求,提出了一种新型工作模式切换控制策略,...     

铁路货车运行品质考核指标研究

简要回顾了我国铁道车辆运行平稳性标准的应用历史和现状,指出其中存在的主要问题,以图寻求改进我国评价铁路货车运行平稳性指标的可行途径。介绍了AAR和UIC中的相应标准的概况;阐述了铁路货车运行平稳性方面的主要矛盾;分析了采用运行平稳性指标评价铁路货车运行品质的一些具体问题。建议增加评价车辆纵向运行平稳性的指标,以更全面地反映和评价车辆的动态运行品质。提出了货车运行平稳性评价体系调整过程中应开展的主要工作和改进我国铁路货车运行平稳性标准的方向。建议以车体加速度峰值和均方根值作为考核铁路货车运行平稳性的主要指标,同时建议修建专用的试验线或扩展现有的试验线,以便更加客观地考核、比较和研究车辆的动态性能。     

轨下支承失效对车辆系统动态响应及乘坐舒适度的影响

建立了基于Timoshenko梁模型的非对称车辆/轨道耦合动力学模型,分析轨下支承失效对车辆乘坐舒适度的影响。钢轨被视为弹性离散点支承上的无限长Timoshenko梁,通过假设轨道系统垂向支承刚度沿纵向分布发生突变来模拟轨下支承失效状态。推导了考虑钢轨横向、垂向和扭转运动的轮轨滚动接触蠕滑率计算公式。利用Hertz法向接触理论和沈氏蠕滑理论分别计算轮轨法向力及轮轨滚动接触蠕滑力。采用移动轨下支承模型分析离散的轨枕支承对系统动力响应的影响。利用新型显式积分法求解车辆/轨道耦合动力学系统运动方程。乘坐舒适度评价采用Sperling指标,通过数值分析,得到直线轨道连续从0到6个轨下支承失效对车辆动态响应及乘坐舒适度的影响。结果表明,轨下支承失效对车辆系统位移、加速度有显著的影响,随着轨下支承失效个数的增加,轮轨力和车辆系统的位移、加速度将会急剧增大,乘坐质量和乘坐舒适度指标呈线性增大,但数值很小。