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991.
Understanding the dynamics of boarding/alighting activities and its impact on bus dwell times is crucial to improving bus service levels. However, research is limited as conventional data collection methods are both time and labour intensive. In this paper, we present the first use of smart card data to study passenger boarding/alighting behaviour and its impact on bus dwell time. Given the nature of these data, we focus on passenger activity time and do not account for the time necessary to open and close doors. We study single decker, double decker and articulated buses and identify the specific effects of floor/entrance type, number of activities and occupancy on both boarding and alighting dynamics. A linear relationship between average boarding and alighting times and their respective standard deviations is also found, whereas the variability of boarding and alighting time decreases with the number of passengers boarding and alighting. After observing the cumulative boarding/alighting processes under different occupancy conditions, we propose a new model to estimate passenger activity time, by introducing critical occupancy – a parameter incorporating the friction between boarding/alighting and on-board passengers. We conduct regression analyses with the proposed and another popular model for simultaneous boarding/alighting processes, finding that the critical occupancy plays a significant role in determining the regime of boarding and alighting processes and the overall activity time. Our results provide potential implications for practice and policy, such as identifying optimal vehicle type for a particular route and modelling transit service reliability. 相似文献
992.
钢筋混凝土构件均匀锈蚀与应力的耦合效应分析 总被引:5,自引:0,他引:5
根据钢筋混凝土锈胀动力学及金属力学化学原理,分析了在混凝土完好的条件下,钢筋应力对锈蚀反应速度的影响。通过计算,确证了均匀锈蚀条件下应力因素对钢筋锈蚀速度无显著影响。 相似文献
993.
车辆——轨道耦合系统随机振动分析 总被引:1,自引:0,他引:1
将轨道高低不平顺视为平稳各态历经随机过程,利用车辆-轨道耦合动力有限元计算模型,对车辆-轨道系统垂向随机动做了计算,在时域和频域内对系统响应作了分析。 相似文献
994.
995.
采用仿真软件SIMPACK建立一种2C0径向转向架机车模型。在该模型中分别考虑了二系垂向减振器、二系横向减振器和二系抗蛇行减振器的端部安装刚度对机车动力学性能,如机车平稳性、临界速度和曲线通过稳定性的影响,提出了相应的设计建议。 相似文献
996.
在永磁同步电机原始结构的基础上对其进行仿真模型的改进,并对不同的改进方案进行仿真计算和对比分析。仿真结果表明通过对流道结构、传热路径和流量三个方面的优化设计显著降低了电机的最高温度。 相似文献
997.
N. Lestoille C. Funfschilling 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2016,54(5):545-567
The influence of the track geometry on the dynamic response of the train is of great concern for the railway companies, because they have to guarantee the safety of the train passengers in ensuring the stability of the train. In this paper, the long-term evolution of the dynamic response of the train on a stretch of the railway track is studied with respect to the long-term evolution of the track geometry. The characterisation of the long-term evolution of the train response allows the railway companies to start off maintenance operations of the track at the best moment. The study is performed using measurements of the track geometry, which are carried out very regularly by a measuring train. A stochastic model of the studied stretch of track is created in order to take into account the measurement uncertainties in the track geometry. The dynamic response of the train is simulated with a multibody software. A noise is added in output of the simulation to consider the uncertainties in the computational model of the train dynamics. Indicators on the dynamic response of the train are defined, allowing to visualize the long-term evolution of the stability and the comfort of the train, when the track geometry deteriorates. 相似文献
998.
999.
《铁道标准设计通讯》2017,(4):1-5
板式减振垫轨道能降低列车运营对周围环境的影响,确保城市轨道交通引起的振动满足环保要求,在高等减振设计中普遍采用。基于轮轨耦合作用,建立城轨列车-板式减振垫轨道-下部基础有限元模型,对不同减振垫刚度下板式轨道结构进行模态、谐振分析,并对其减振性能进行研究。研究表明:(1)减振垫轨道结构的固有频率随着减振垫刚度的增大而增大,振型包括轨道板的平动、转动、弯曲和钢轨的侧翻、扭转;(2)钢轨至轨道板的传递损失集中在15~30 d B,而轨道板至基底的传递损失峰值达51 d B;(3)车体加速度、轮轨垂向力、钢轨加速度、基底垂向加速度随着减振垫刚度的增大呈增大趋势,而钢轨位移、轨道板加速度和位移呈减小趋势;(4)板式减振垫轨道在25~100 Hz频段的减振效果较好,特别是1/3倍频程中心频率63 Hz处,插入损失达24 d B;在1~25 Hz频段的减振效果一般,而且局部频段出现振动放大的情况。 相似文献
1000.