平行轨行车智能纠偏控制系统设计

针对平行轨行车在生产运行过程中常出现的偏轨现象,分析了其偏移的原因,提出了相应的纠偏方案及一套完整的自动纠偏系统,对纠偏系统中的关键部件及结构形式进行了详细的探讨与分析。通过现场系统的调试与纠偏效果前后比较,表明该系统实现了平行轨行车的自动纠偏功能,提高了自动化水平。

地铁施工用电动轨行车设计

介绍在郑州地铁1号线施工中使用的电动轨行车的设计,包括车架、轮对、电机、传动、换挡机构、制动系统以及控制电器的设计计算和选用。在地铁施工中安装支架,如果在该车辆上安装操作平台,可进行打眼及接触网调整作业,还可运送1.5 t以下的接触网导线以及进行现场检查等。

异轨双行车并车吊装法在海外某核电站的应用

核电站500 t级发电机定子有多种吊装方法,其中利用厂房既有行车吊装是最经济可行的。2台行车一大一小,高低跨布置,刚性并车就难以实施。结合海外某核电站工程,系统介绍了异轨双行车并车吊装法,通过采用虚拟并车技术克服了并车技术难题,顺利完成了2台发电机定子吊装。吊装方法充分利用既有起重设备,具有影响范围小、吊装效率高、施工成本低等技术特点。

桥式装卸吊更换行车承轨梁的实践体会

本文对桥式装卸吊行车承轨梁进行技术改造 ,并成功地解决行车承轨梁严重的疲劳缺陷隐患 。

“滑轨式”折叠自行车首次亮相东京

来自中国台湾地区嘉广实业公司的一款“滑轨式”微型折叠式自行车，此次在“2004东京国际自行车展”上同样也吸引了不少观众和自行车采购商的目光，出尽了风头。据生产厂商介绍，这款在日本东京初次“崭露头角”、称之为“滑轨式”的折叠自行车，因车架能够像滑轨那样自由“伸缩”，车身的长度尺寸可根据需要随意调整，因此，不论是少年儿童，

轨行式起重机抗震台车

最近,在工程机械领域内,对于提高机械的安全性能问题越来越被人们所重视。其中重要的一环是如何提高机械的抗震性能。不论是设置在室内的还是露天设置的起重机,当它倒塌时会给其周围的人和物带来很大的危害。但是以往对于起重机来说,一般都没有考虑抗震问题。其结果,一旦地震发生时,如果地震的震动频率和起重机的固有频率相同或接近,起重机就容易倒塌。

A novel refined dynamic model of high-speed maglev train-bridge coupled system for random vibration and running safety assessment

Running safety assessment and tracking irregularity parametric sensitivity analysis of high-speed maglev train-bridge system are of great concern,especially need perfect refinement models in which all properties can be well characterized based on various stochastic excitations.A three-dimensional refined spatial random vibration analysis model of high-speed maglev train-bridge coupled system is established in this paper,in which multi-source uncertainty excitation can be considered simultaneously,and the probability density evolution method(PDEM)is adopted to reveal the system-specific uncertainty dynamic characteristic.The motion equation of the maglev vehicle model is composed of multi-rigid bodies with a total 210-degrees of freedom for each vehicle,and a refined electromagnetic force-air gap model is used to account for the interaction and coupling effect between the moving train and track beam bridges,which are directly established by using finite element method.The model is proven to be applicable by comparing with Monte Carlo simulation.By applying the proposed stochastic framework to the high maglev line,the random dynamic responses of maglev vehicles running on the bridges are studied for running safety and stability assessment.Moreover,the effects of track irregularity wavelength range under different amplitude and running speeds on the coupled system are investigated.The results show that the augmentation of train speed will move backward the sensitive wavelength interval,and track irregularity amplitude influences the response remarkably in the sensitive interval.

A Trajectory-Oriented Carriageway-Based Road Network Data Model, Part 3: Implementation

This is the final of a three-part series of papers which mainly discusses the implementation issues of the CRNM. The first two papers in the series have introduced the modeling background and methodology, respectively. An overall architecture of the CRNM has been proposed in the last paper. On the basis of the above discusses, a linear reference method (LRM) for providing spatial references for location points of a trajectory is developed. A case study is introduced to illustrate the application of the CRNM for modeling a road network in the real world is given. A comprehensive conclusion is given for the series of papers.

大型空分装置中压缩机厂房的高度设计

分别以电力驱动的压缩机和以蒸汽透平驱动的压缩机为例简要论述压缩机厂房高度设计的要点。

Roadbed behavior subjected to tilting-train loading at rail joint and continuous welded rail

The tilting-train is very attractive to the railroad users in the world due to the advantage of high speed in curved track using pre-existing infrastructure of railway.Tilting-train has a unique allowable speed and mechanism especially in curved track.In this work,when tilting-train is operated with the allowable speed,the behavior of roadbed is evaluated by examining its settlement and bearing capacity.Additionally,the stability of roadbed is estimated as the roadbed is in the condition of soft soil influenced by the weather effects and cyclic train loading.Numerical results show that the roadbed settlement satisfies the allowable settlement when the elastic moduli of upper roadbed and in-situ soil are greater than 3800 and 4600 kN/m2 for rail joint and 2300 and 3300 kN/m2 for continuous welded rail(CWR).

Dynamic analysis of a high-speed train operating on a curved track with failed fasteners

A high-speed train-track coupling dynamic model is used to investigate the dynamic behavior of a high-speed train operating on a curved track with failed fasteners. The model considers a high-speed train consisting of eight vehicles coupled with a ballasted track. The vehicle is modeled as a multi-body system, and the rail is modeled with a Timoshenko beam resting on the discrete sleepers. The vehicle model considers the effect of the end connections of the neighboring vehicles on the dynamic behavior. The track model takes into account the lateral, vertical, and torsional deformations of the rails and the effect of the discrete sleeper support on the coupling dynamics of the vehicles and the track. The sleepers are assumed to move backward at a constant speed to simulate the vehicle running along the track at the same speed. The train model couples with the track model by using a Hertzian contact model for the wheel/rail normal force calculation, and the nonlinear creep theory by Shen et al. (1984) is used for wheel/rail tangent force calculation. In the analysis, a curved track of 7000-m radius with failed fasteners is selected, and the effects of train operational speed and the number of failed fasteners on the dynamic behaviors of the train and the track are investigated in detail. Furthermore, the wheel/rail forces and derailment coefficient and the wheelset loading reduction are analyzed when the high-speed train passes over the curved track with the different number of continuously failed fasteners at different operational speeds. Through the detailed numerical analysis, it is found that the high-speed train can operate normally on the curved track of 7000-m radius at the speeds of 200 km/h to 350 km/h.

Temperature-induced deformation of CRTS II slab track and its effect on track dynamical properties

Two finite-element models of the CRTS II slab track are presented to simulate temperature-induced deformations of the concrete track slab with no deterioration or with a deteriorated cement asphalt mortar(CAM).One model,which considers the fully bonding interface between the slab and the CAM layer,could applied to a track that is in good condition;the other model uses cohesive zone elements to simulate the deteriorated CAM with some possible interfacial separation and slip.Utilizing both of the models,temperature-induced warp deformations of track under various temperature loads are investigated.The influence of temperature deformation on the dynamic properties of the track is analyzed based on the train-track coupled dynamics.Numerical results show that the deteriorated CAM layer can significantly increase temperature deformations of a CRTS II track slab,which would produce tiny rail irregularities.There are clear differences between the deformation shapes of the track slabs that have an inseparable mortar layer and those have a separable mortar layer.The track slab with a deteriorated mortar layer showed more open curl distortion than the track slab in good condition.The dynamical response index of the slab track is intensified to a certain level due to the temperature deformation;with an increase of the train speed,the track dynamical responses increased linearly.However,rail irregularities due to the temperature deformations are very tiny.Even if a track is exposed to extreme temperature loads and the mortar layer is deteriorated,temperature deformation can have a negligible effect on the track’s dynamical properties.