敞开式TBM施工铁路隧道仰拱预制块关键设计参数研究

以敞开式TBM施工特长铁路隧道仰拱预制块结构为研究背景,基于荷载结构设计理论,采用有限元软件ANSYS构建二维平面分析模型,研究了仰拱预制块圆心角、中心水沟沟槽深度、宽度等参数对衬砌结构变形、受力特性的影响规律。研究结果表明:圆心角对仰拱预制块变形、内力影响较小,设计中应根据仰拱预制块拼装技术及轨道结构要求来确定;中心水沟沟槽底至仰拱预制块底部间距h对仰拱预制块变形、内力影响较大,设计中间距h应大于复合式衬砌厚度;扩大中心水沟宽度,可有效降低集中应力值,在满足轨上结构承载能力的前提下,设计中可适当扩大中心水沟宽度来增大隧道排水能力。     

Design safety margin of a 10,000 TEU container ship through ultimate hull girder load combination analysis

Assessment of the ultimate longitudinal strength of hull girders under combined waveloads can be of particular importance especially for ships with large deck openings and low torsional rigidity. In such cases the horizontal and torsional moments may approach or exceed the vertical bending moment when a vessel progresses in oblique seas. This paper presents a direct calculation methodology for the evaluation of the ultimate strength of a 10,000 TEU container ship by considering the combined effects of structural non-linearities and steady state wave induced dynamic loads on a mid ship section cargo hold. The strength is evaluated deterministically using non-linear nite element analysis. The design extreme values of principal global wave-induced load components and their combinations in irregular seaways are predicted using a cross-spectral method together with short-term and long-term statistical formulations. Consequently, the margin of safety between the ultimate capacity and the maximum expected moment is established.     

Methodologies to monetize the variations in load factor and GHG emissions per passenger-mile of airlines

Global GHG emissions from air travel are currently at 3% and it could increase to 15% of the total GHG emissions by 2050. To curb the growth of GHG emissions from air travel, the U.S. Federal Aviation Administration (FAA) has created a policy to achieve carbon neutral growth by 2020 relative to the 2005 baseline. If the airline industry is to both grow and meet the objectives set by this policy, new and innovative aircraft designs, operational efficiencies, and widespread use of alternate fuels are required. To accomplish this would require large research and development investment. The federal government and state governments have passed legislations that provide tax breaks and other incentives to encourage investments in new technologies. One such tax policies is cap and trade system. This had partial success in reducing GHG emissions in certain industries but was not successful in the airline industry. This paper presents alternate methods to raise capital to invest in GHG emissions reduction projects in the airline sector. The four methodologies presented here monetizes the GHG emissions resulting from differences in load factor (ratio of number of passengers to number of seats) and GHG emissions per passenger-mile among different airlines, among different flight sectors, etc. to raise the capital. Based on 2012 air travel data, these methodologies could raise more than $300 million dollars annually to invest in GHG emissions reduction projects.     

基于自适应卡尔曼滤波的商用车横向载荷转移率估计

为解决商用车由于质心高、轮距小而易发生侧翻事故的问题,建立了3自由度参考模型,提出了基于自适应卡尔曼滤波算法的状态估计器,并以估计器估计结果对车辆状态和横向载荷转移率进行计算.利用TruckSim仿真软件对自适应卡尔曼滤波估计算法进行了验证,验证工况为30 km/h和90 km/h双移线工况.通过估计结果与仿真数据对比,验证了此估计算法能够很好地估计计算车辆状态和车辆横向载荷转移率值.     

中国铁路客票发售和预订系统5.0版的研究与实现

为适应铁路客运快速网的建设与发展，满足铁路第6次大提速以及客运新产品销售的需求，研发铁路客票系统5．0版。系统继续采用集中与分布相结合的客户／服务器体系结构，席位全部集中到各地区数据中心，车站可不设置服务器。系统为3级体系结构，由铁道部数据中心、地区数据中心和所辖车站系统组成；每一级系统均包括数据逻辑层、应用逻辑层和表示逻辑层。系统数据库包括基础数据库、运行数据库、营销数据库和算法库4个库。系统功能设计包括铁道部中心系统功能体系，地区中心系统功能体系和车站系统功能体系3部分。系统创新性地实现了席位的集中管理和售票组织策略；开发了客票应用服务器、客票接口平台、数据传输系统和客票营销系统；支持取消车站服务器，支持地区中心由业务中心向数据中心转变；优化了票价计算策略的和数据复制策略等。系统已于2006年8月底完成在全路的推广与实施。     

基于试验场道路的变速器台架载荷谱研究

通过实车采集试验样车在试验场道路上行驶时的CAN BUS数据,可直接获得发动机转速、扭矩和档位等信号;把传统的载荷-时间频次关系,转变为载荷-发动机飞轮旋转频次关系,同时记录各载荷等级对应的各个挡位的频次,这样可获得在各个档位下,不同载荷等级对应转速区间内的飞轮旋转频次,根据齿轮材料的S-N曲线和疲劳累积Miner理论,计算出各档位的疲劳强度,然后基本疲劳损伤等效原理选取各档位下产生较大疲劳强度的扭矩和转速,作为台架试验输入的载荷和转速,可有效避免载荷和转速选取的盲目性,为科学的制定台架试验载荷谱提供了依据。     

采用模糊加载控制的大功率筑机传动实验台

针对目前传动实验台存在的问题，提出了一种大功率直流合流控制方案，加载方式上采用模糊控制，减少了超调，提高了加载的平滑性，节电效果明显。     

铆接钢桥剩余寿命与使用安全评估

基于铆接钢桥的疲劳损伤演化机理,以及铆接结构多破坏模式和铆接多成份、多构件的疲劳失效论与方法进行系统研究,建立基于疲劳累积损伤理论、断裂力学和可靠度理论的铆接钢桥使用安全评估系统。本文研究工作主要表现在以下几个方面。(1)针对我国公路与铁路桥梁设计规范尚未对交通荷载谱模拟做出规定的不足,在现场交通观测和应力谱实测基础上,运用MonteCarlo模拟技术,实现公路与铁路桥梁交通荷载谱和应力谱的模拟。通过上海市浙江路桥和京九线赣江桥计算应力谱与实测应力谱的对比分析,表明本文建立的交通荷载谱可用于疲劳寿命评估。(2)…     

船体强度三维有限元分析的载荷直接计算和验证

采用载荷直接计算法对鞭船船体强度进行三维有限元分析，并用该船的实航测试数据和“船体梁理论”进行了验证和讨论。     

动力定位船控位能力计算软件平台构建研究

围绕环境载荷计算和推进器推力分配两大关键问题,对控位能力计算软件平台功能实现进行设计。通过对环境载荷计算、推进器配置、推力分配、动力定位能力图绘制等功能进行集成,完成界面友好的控位能力计算软件平台。最后通过实例验证了自研软件的稳定性与输出结果的可靠性。