基于VBA的三牙轮钻头CAD系统

阐述了以AutoCAD为二次开发平台,利用内嵌于AutoCAD的VBA语言进行编程,开发三牙轮钻头计算机辅助设计系统的思想。对系统进行总体框架设计,确定三牙轮钻头CAD系统的功能模块,将系统分为界面管理模块、钻头齿面结构设计模块、数据库管理模块、参数化绘图模块、辅助功能模块5大模块。     

热油管道的程序设计

针对热油管道输送过程中的计算问题,应用计算机技术实现复杂计算,使用VB编程,用计算机实现热油管道的加热站数目、油输量、站间摩阻、泵站数等的计算.通过和实际数值的对比,编制的程序可以进行长输管道工艺计算,为以后相关软件的研制奠定了基础.     

用Visual Lisp开发波纹管膨胀节设计软件

波纹管膨胀节是目前国内外广泛使用的一种管道构件，在管网上起连接、补偿等作用。本文以AutoCAD14作为操作平台，用Visual Lisp作为二次开发语言，编辑设计软件，对波纹管和膨胀节产品图纸进行设计，从界面制作、图库建立、数据库建立、参数设计、图纸绘制到打印输出建立一套完整的计算机辅助设计开发软件，从而缩短设计周期，避免设计误差和设计错误，提高设计质量。     

流体在管道中流动参数的计算（一）

介绍了牛顿流体在管道中的摩擦系数，流速及流速分布，压力降以及阀门和管件中压力降的计算方法。     

管道通径仪仿真牵拉实验系统

介绍了管道内检测通径仪仿真牵拉实验系统的组成及工作原理,并通过大量实验证明该仿真实验系统可以有效地对通径仪各种工作性能进行验证,解决了进行实际牵拉实验困难的问题,对管道内检测设备在进行管道现场工业施工过程中准确地测量管道里程起着关键作用,从而在进行管道维修开挖时能够更准确,明显减小了管道维修开挖的误差。     

基于有限元法的海底管道轴向移动研究

针对裸置于海床上的单层非保温海管,通过有限元法,研究海管在多个加热/冷却循环过程中的轴向移动问题,并分析不同参数对管道轴向移动的影响。结果显示:管道壁厚、内压对管道轴向位移影响较小,管道长度、土体摩擦系数对管道轴向移动影响较大;当参数的变化使部分管段形成虚拟锚固区或管土之间摩擦力增大时,管道轴向位移将会减小。     

基于WEBGIS的管道调度运行管理系统

利用GIS空间分析功能并结合计算机对整个成品油管道运行过程的主要参数、管道信息、分输站运行状况进行动态监测、实时调度和自动化控制,实现自动化信息管理。并以WEBGIS为基础,建立管道调度运行管理系统,将管道的运行状态实时地提供给管理者,对各分输站点进行自动控制,并根据经济、技术指标和实际情况,进行优化控制反馈,可以协助管道管理者对成品油管道进行安全高效的运营管理。     

基于SCADA系统的燃气管道泄漏监测系统模型设计

单一的燃气管道泄漏检测系统不经济,SCADA系统不仅能为泄漏检测提供数据源,而且能监控管道运行状况.因此,将检测系统集成到SCADA系统中,不但能充分利用SCADA系统的功能,而且也是管道自动化发展方向.介绍了城市燃气管道现有的监测技术和发展方向、输气管道检漏方法、管道泄漏监测技术的研究方法;设计了城市燃气管道温度、压力、流量的数据采集方案、原理、模型和采集的程序流程;给出了在VB中使用MSComm控件进行串口通信以及实现PC机对下位机的数据采集的方法;给出了用VB进行油气管道数据采集的编程步骤和部分界面.     

AutoPIPE在输油埋地管道中的应用

埋地管道应力分析的关键在于准确模拟土壤对管道的作用,研究管道周围的土壤力学性能是正确进行埋地管道应力分析的前提。基于AutoPIPE管道应力分析软件,首先对国际上埋地管道理论进行简单的介绍,然后结合该理论对某工程中的埋地输油管道建立了较准确的应力分析模型,进行了较细致全面的应力分析,并指出当地上管道柔性足够时,埋地管道出土入土处端点位移较小,不需要设计固定墩。对管道应力分析工作者利用AutoPIPE进行埋地管道应力分析具有一定的借鉴意义。     

换热器CAD系统中的接口技术

介绍ActiveX Automation技术以及基于该技术，建立应用程序与AutoCAD间的通讯，实现AutoCAD的二次开发。并展示了ActiveX Automation技术在以Visual Basic为开发工具编制的换热器计算机辅助设计软件系统中的应用。     

基于AUTOCAD的ANSYS几何建模初探

基于AutoCAD平台,用其自带的VBA开发应用程序,建立了从AutoCAD单线几何模型到ANSYS杆系模型的转换接口程序,该程序可将在AutoCAD环境下建立的复杂空间模型转换成ANSYS中的结构模型,方便快捷实现土木工程中复杂的几何建模功能,为工程计算和研究提供方便。通过自定义截面和空间网架建模两个实例验证了该方法的可行性和实用性。     

Energy saving potentials of connected and automated vehicles

Connected and automated vehicles (CAV) are marketed for their increased safety, driving comfort, and time saving potential. With much easier access to information, increased processing power, and precision control, they also offer unprecedented opportunities for energy efficient driving. This paper is an attempt to highlight the energy saving potential of connected and automated vehicles based on first principles of motion, optimal control theory, and a review of the vast but scattered eco-driving literature. We explain that connectivity to other vehicles and infrastructure allows better anticipation of upcoming events, such as hills, curves, slow traffic, state of traffic signals, and movement of neighboring vehicles. Automation allows vehicles to adjust their motion more precisely in anticipation of upcoming events, and save energy. Opportunities for cooperative driving could further increase energy efficiency of a group of vehicles by allowing them to move in a coordinated manner. Energy efficient motion of connected and automated vehicles could have a harmonizing effect on mixed traffic, leading to additional energy savings for neighboring vehicles.     

X52焊缝失效评定曲线

失效评定曲线被广泛应用于管道的断裂评定,针对严重影响国内在役老管道安全运行的焊缝问题,建立焊缝失效评定曲线.以在役老管道常用管材X52为例,采用R6方法建立焊缝失效评定曲线(选择3曲线),并与R6选择1曲线和选择2曲线比较,表明选择3曲线的精确性对于在役管道焊缝失效精确评估的重要性.给出了3种焊缝材料特性的失效评定曲线...     

静力作用下沉管隧道三维数值模拟

沉管隧道纵断面结构计算常采用弹性地基梁或弹性地基板法,但这些方法较难真实模拟沉管隧道的受力情况,特别是接头的受力情况。文章以三维实体单元出发,引入适当的假设,对沉管隧道静力作用下的受力、位移,特别是接头受力情况进行了详细的模拟分析,对沉管隧道结构纵向计算做了有益的探索,对类似工程有较强的指导意义。     

On the fundamental diagram and supply curves for congested urban networks

Macroscopic fundamental diagrams (MFD) of traffic for some networks have been shown to have similar shape to those for single links. They have erroneously been used to help estimate the level of travel in congested networks. We argue that supply curves, which track vehicles in their passage through congested networks, are needed for this purpose, and that they differ from the performance curves generated from MFD. We use a microsimulation model, DRACULA and two networks, one synthesizing the network for Cambridge, England, and one of the city of York, England, to explore the nature of performance curves and supply curves under differing patterns of demand.We show that supply curves differ from performance curves once the onset of congestion is reached, and that the incorrect use of performance curves to estimate demand can thus seriously underestimate traffic levels, the costs of congestion, and the value of congestion relief measures. We also show that network aggregated supply curves are sensitive to the temporal distribution of demand and, potentially, to the spatial distribution of demand. The shape of the supply curve also differs between origin–destination movements within a given network.We argue that supply curves for higher levels of demand cannot be observed in normal traffic conditions, and specify ways in which they can be determined from microsimulation and, potentially, by extrapolating observed data. We discuss the implications of these findings for conventional modelling of network management policies, and for these policies themselves.     

Development of transitioned vertical curve I Properties

Introducing spiral curves before and after horizontal circular curves has been widely accepted to enhance traffic safety, highway esthetics, sight distance, and driver comfort. Though, vertical curves are still designed as parabolic curves that are connected directly to the tangent (without transitions). In this paper, a cubic polynomial is used to develop a vertical transition curve before and after the parabolic vertical curve. The resulting curve, called transitioned vertical curve, consists of transition-parabolic-transition segments. Detailed mathematical formulation and derivation of the instantaneous elevation, grade, rate of curvature, and offset from the first tangent at any point are presented. The highest (or lowest) point on a transitioned crest (or sag) vertical curve, where the instantaneous grade equals 0, is determined as it is of particular importance in highway drainage design. The minimum length of a transition curve is derived based on the criterion of driver comfort. In addition, guidelines are provided to identify the conditions where the drainage of surface water on transitioned curves can be a concern. Finally, the layout of the transitioned vertical curve is described and illustrated using two numerical examples. The new transitioned vertical curve, which exhibits striking similarities to the spiraled horizontal curve, should enhance the design of highway vertical alignments.     

Measurement uncertainty determination and curve-fitting algorithms for development of accurate digital maps for advanced driver assistance systems

Digital maps can provide support for numerous advanced driver assistance systems (ADAS) aimed at improving road safety. These new uses require more highly detailed and precise maps. The use of a datalog vehicle to collect roadway geometry data can fulfil these specifications. This paper presents fast, accurate measurement with an on-board inertial system together with a method to evaluate measurement uncertainty, particularly for any variables obtained indirectly. It also presents an algorithm for segmentation and fitting geometric curves to the experimental points, following current highway design standards. The algorithms have been applied to real road measurements. Segmentation has been done in straight alignments, circular curves and transition curves whose characteristic parameters are calculated. It has been seen that with a very small data set it is possible to reconstruct the measured geometry with few discrepancies regarding the experimental points.     

油田内部热油管道最佳操作参数的快速确定

由于油田内部热油管道操作参数上的不合理,给油田生产造成了不必要的能量损耗。利用管道分段的方法,通过热力和水力计算,生成出站参数曲线图,方便快捷的为油田内部的热油管道确定最佳的出站（管道起点）加热温度和出站压力,减少能源的浪费。计算中,考虑了流量、含水量、黏度变化等因素,为流量和含水量不断变化的油田内部加热输油管道的优化运行提供参考。     

A note on consistency of choice units in entropy models

In using entropy maximization models to forecast locational and travel behaviour, one is confronted with the problem of delineating the choice process as precisely as possible. In addition to defining a fine-grain choice structure implying individuals seeking distinct location sites within residential zones and travelling to distinct jobs or shops within destination zones, this note also accounts for the fact that the location choice is of a site for a household or firm, but the corresponding travel choices are by individual members of a household. In conjunction with disaggregation across quantities with large variance, the above principles are applied to formulate improved versions of residential and shopping location models.