钢桥面力学分析合理有限元模型研究

钢箱梁桥面板的结构特性直接影响着其上沥青铺装层的受力,因此进行有限元力学分析时必须确定合理的结构模型。在多次计算的基础上,通过比较相同荷载作用下模型各个关键结点的位移、应力、应变等力学指标,最终确定了横向上包括6个U形加劲肋、纵向上包括3跨面板范围的基本简化模型,并对单元类型、单元大小等进行了讨论。通过实桥检测,验证了简化模型的可行性,分析了理论计算值与实测值误差的来源。     

南京长江三桥深水基础钢套箱施工

深水基础施工是大桥施工的重点,如何合理地选择其施工方案是保证大桥按期顺利完成、降低工程造价的关键。本文介绍了长江三桥钢围堰施工方案的比选及其施工要点,以供参考。     

横向减振器对机车平稳性能的影响

基于机车车辆-轨道耦合动力学理论,运用TTISIM(Train/Track Interaction Simulation)仿真软件,以横向减振器为研究对象,以机车运行平稳性指标为依据,系统分析了机车横向减振器的阻尼参数、工作状态、卸荷速度和悬挂位置等参数对于机车平稳性能的影响。仿真计算与分析结果表明:选取适当横向减振器的结构阻尼参数,对提高机车的平稳性有利;采取适当的减振器卸荷速度可以达到提高乘车舒适性的目的;横向减振器是否正常工作对机车的运行品质有较大影响,必须严格确保所有减振器的正常工作;横向减振器的悬挂位置,对于车体的运行平稳性几乎没有影响。     

Feasibility of localizing in vivo micro-devices with electromagnetic methods

In order to measure the location of medical micro-devices in the gastrointestinal tract, electromagnetic methods were developed considering the magnetic permeability of human bodies. Two varieties of electromagnetic localization methods have been implemented： one uses direct current（DC） to generate the electromagnetic field, and the other uses alternating current （AC）. The two varieties of the localization principle were analyzed and relevant experiments were made. The experiments show that the alternating electromagnetic method acquires higher accuracy, higher stability and wider measurement range.     

Connecting e-hailing to mass transit platform: Analysis of relative spatial position

This paper analyzes and compares two different relative spatial position (RSP) designs in an integrated e-hailing/fixed-route transit system: a zone-based design that operates e-hailing vehicles within a zone, and a line-based design that operates e-hailing vehicles along a fixed-route transit line and with a stable headway. To conduct a meaningful comparison, the optimal design problems for both systems are formulated using a same analytical framework based on the continuous approximation approach. A comprehensive numerical experiment is performed to compare various cost components corresponding to the optimal designs, and a discrete-event simulation model is developed to validate the analysis. The analytical and simulation results agree with each other well, with a discrepancy in the total system cost less than 5% in most test scenarios. These results also suggest that the line-based system consistently outperforms the zone-based system in terms of both agency and user costs, for all scenarios tested. Compared to the zone-based design, the line-based design features a sparser fixed-route network (resulting in larger stop spacing) but a higher dispatching frequency. It is concluded that the higher efficiency of the line-based design is likely derived from the strategy of operating e-hailing vehicles with a more regular route/headway structure and allowing ride-sharing.     

基于模糊层次分析法的炮兵阵地综合评估

运用模糊数学原理和方法,建立了炮兵阵地的评价因素指标体系.运用模糊层次分析法（FAHP）,构造模糊一致性判断矩阵,确定各层因素指标的权重,经过多级模糊运算后,对所选阵地进行综合评估。     

台湾船员培训、考试和发证现状研究

在两岸“大三通”的背景下，开展我国台湾地区船员参加大陆船员培训、考试和发证工作，拓展两岸船员劳务合作空间，具有积极的现实意义，文中对两岸船员的培训、考试和发证制度进行研究比较分析，从法律、行政管理和技术层面探讨台湾地区船员参加大陆船员培训、考试和发证工作，及两岸船员劳务多层次交流合作的可行性，并对具体做法提出建议，为今后开展相应工作提供参考。     

Estimation of wheel–rail friction for vehicle certification

In certification of new rail vehicles with respect to running characteristics, a wide variety of operating conditions needs to be considered. However, in associated test runs the wheel–rail friction condition is difficult to handle because the friction coefficient needs to be fairly high and the friction is also generally hard to assess. This is an issue that has been studied in the European project DynoTRAIN and part of the results is presented in this paper. More specifically, an algorithm for estimating the wheel–rail friction coefficient at vehicle certification tests is proposed. Owing to lack of some measurement results, the algorithm here is evaluated in a simulation environment which is also an important step towards practical implementation. A quality measure of the friction estimate is suggested in terms of estimated wheel–rail spin and total creep. It is concluded that, tentatively, the total creep should exceed 0.006 and the spin should be less than 1.0 m^?1 for the algorithm to give a good friction estimate. Sensitivity analysis is carried out to imitate measurement errors, but should be expanded in further work.     

跨海钢混结合梁斜拉桥边跨施工方案研究

福厦客专安海湾特大桥主桥为国内首座跨海高速铁路结合箱形截面梁斜拉桥,该桥主桥采用(40+135+300+135+40)m双塔双索面斜拉桥跨越安海湾航道。本文结合桥址处水浅、滩涂发育,潮汐明显,周围养殖密布等影响因素,对边跨钢箱梁进行了悬臂拼装施工、高位支架滑移施工、高位支架顶推施工等多方案比选,同时针对顶推方案又从顶推过程是否设置前导梁,是否一次性带桥面板上桥及实施中所用工装设备、顶推支架进行了综合比选,重点对无导梁不带板顶推施工方案进行了介绍,为以后类似工程施工提供借鉴。     

基于中国人体驾乘姿态的汽车人机空间布置研究

合理的人机空间布置对汽车的舒适性与安全性至关重要,人体驾乘姿态是汽车人机空间布置的依据。文章设计试验,扫描得到500样本分别在8辆车中的驾乘姿态数据,对数据进行统计分析,建立驾驶员座椅适宜线方程与中国人体2D模板,基于标杆车进行验证,结果显示,方程及模板精度较高,符合中国人体驾乘特征。该研究为汽车人机空间布置提供理论依据,为研发适合中国人驾乘的车辆提供支撑,对建立中国汽车人机设计体系具有重要意义。