利用钢轮托车辅助盾构机过站施工技术

针对地铁盾构法施工中盾构机通过满足过站要求的已完工车站进行二次始发这一常见施工环节,介绍一种通过钢轮托车辅助盾构机空载推进实现过站需要的施工技术及相应施工要点,如盾构机过站的施工工艺流程,钢板、钢轮拖车及轨道的铺设等。论述了利用钢轮拖车辅助盾构机过站施工技术采取的质量控制、安全措施及环保措施,分析了采用该技术的经济、社会和环境效益。     

基于UDEC仿真的滚刀最优刀间距确定方法

为了得到指定切深下合理的刀间距,提出一种基于UDEC仿真的滚刀最优刀间距确定方法。通过试验机得到岩样力学参数,利用2D离散元仿真软件UDEC,建立了无围压条件下两把滚刀顺次切削节理不发育岩石的数学模型,在此基础上设计了一组数值试验,成功地模拟出了不同切深和刀间距下滚刀破碎岩石的全过程。分析得到指定切深下仿真切削比能耗与刀间距的对应关系,最小比能耗下的刀间距即为最优刀间距。最后,利用回转式盾构刀具切削实验台,采用恒切深方式进行多组实验,记录刀具所受三向力和破碎岩样重量,得到实验最优刀间距。通过实验手段和仿真手段得到的最优刀间距基本一致,工程数据也进一步证实了这一点。因此,基于UDEC仿真的滚刀最优刀间距确定方法是可行的。     

变频器输出电压du/dt对电机的影响及其滤波器的设计

研究了变频器输出电压du/dt对电机端电压和轴承电流的影响,在PSpice中建立了电机高频模型,并对端电压波形进行了仿真;着重研究了一种du/dt滤波器的参数设计方法,并且进行了仿真和实验验证。实践证明,该滤波器具有较好的滤波效果。     

汽车吸能转向机构与驾驶员碰撞的仿真与试验

利用非线性有限元方法建立了可收缩吸能转向机构与驾驶员所组成碰撞系统的仿真模型，深入讨论了碰撞仿真模型初始条件与边界条件的处理方法、材料非线性本构关系的选择、接触对摩擦系数的确定。并按照GB11557规定的要求，对人体模块有限元模型进行了验证。分析计算了吸能转向机构与人体模块碰撞时上下套管间的收缩位移和作用在转向柱上的碰撞力，并通过相应的碰撞台架试验验证了仿真结果的正确性。     

CARD/1系统在互通立交设计绘图上的应用与开发

通过对CARD/1系统在T型（Y型）互通式立体交叉设计绘图上的二次开发，使T型（Y型）互通式立体交叉的设计绘图达到一体化。     

成品油管输水力计算

将成品油管流摩阻因数计算公式分为适用于设计计算和适用于工况分析两类，提出立足于应用计算机，在整个紊流区用科尔布鲁克混合摩擦管公式计算的思想，并用它构建单油品输送和多油品顺序输送新型压能平衡方程，以提高计算精度和避免分区计算。     

能感受负载的节能液压系统

提高大中液压传动的效率日渐成为系统设计的主要目标。较理想的系统应有能力在任何情况下使油泵流量恰好满足负载变化要求，而油压仅比负载压力略高一较小值。这里所介绍的是一种能感受负载的液压系统的工作原理，这能时刻根据负载情况调整泵压和流量，达到上述要求，因此具有优良的节能效果和操作性能。     

Wheel-rail contact models for vehicle system dynamics including multi-point contact

Advanced modelling of rail vehicle dynamics requires realistic solutions of contact problems for wheels and rails that are able to describe contact singularities, encountered for wheels and rails. The basic singularities demonstrate themselves as double and multiple contact patches. The solutions of the contact problems have to be known practically in each step of the numerical integration of the differential equations of the model. The existing fast, approximate methods of solution to achieve this goal have been outlined. One way to do this is to replace a multi-point contact by a set of ellipses. The other methods are based on so-called virtual penetration. They allow calculating the non-elliptical, multiple contact patches and creep forces online, during integration of the model. This allows nearly real-time simulations. The methods are valid and applicable for so-called quasi-Hertzian cases, when the contact conditions do not deviate much from the assumptions of the Hertz theory. It is believed that it is worthwhile to use them in other cases too.     

Greenhouse gas emissions from ships in ports – Case studies in four continents

Emissions of GHG from the transport sector and how to reduce them are major challenges for policy makers. The purpose of this paper is to analyse the level of greenhouse gas (GHG) emissions from ships while in port based on annual data from Port of Gothenburg, Port of Long Beach, Port of Osaka and Sydney Ports. Port call statistics including IMO number, ship name, berth number and time spent at berth for each ship call, were provided by each participating port. The IMO numbers were used to match each port call to ship specifications from the IHS database Sea-web. All data were analysed with a model developed by the IVL Swedish Environmental Research Institute for the purpose of quantifying GHG emissions (as CO₂-equivalent) from ships in the port area. Emissions from five operational modes are summed in order to account for ship operations in the different traffic areas. The model estimates total GHG emissions of 150,000, 240,000, 97,000, and 95,000 tonnes CO₂ equivalents per year for Gothenburg, Long Beach, Osaka, and Sydney, respectively. Four important emission-reduction measures are discussed: reduced speed in fairway channels, on-shore power supply, reduced turnaround time at berth and alternative fuels. It is argued that the potential to reduce emissions in a port area depends on how often a ship revisits a port: there it in general is easier to implement measures for high-frequent liners. Ships that call 10 times or less contribute significantly to emissions in all ports.     

船用伙食冷库自控系统的改造设计

文章针对早期船用伙食冷库以继电器为主导的控制系统所存在的问题,以某一滚装客船冷库为例,根据该冷库的运行技术特点,开发出以西门子s7系列可编程控制器为核心的自动控制系统,满足了冷库运行过程的精确掌控、节约耗能和可靠性等要求。