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1.
简述了液压成形过程中胀形力的控制、溢流压力设定、胀形压力计算及简捷有效的调节方法。  相似文献   

2.
采用新型工艺制造波纹管的高效成型设备,其中分体式模具和铰链式锁模机构、链销式排片机构,胀形密封跟进机构及成型压力稳定系统使生产出来的波纹管无论从几何精度还是表面质量较以前都有提高,而且适用范围更广泛,效率更高。  相似文献   

3.
介绍了U型波纹管的液压成型原理及成型过程,给出了成型模具的设计、结构、充油系统的组成,液压元件的选择及压力计算公式。  相似文献   

4.
硫酸盐渍土松胀和盐胀工程性质浅析   总被引:1,自引:0,他引:1  
从硫酸盐渍土松胀、盐胀成因,土质与土体密度、土中含水量、温度、盐分含量四因素对硫酸盐渍土盐胀的影响,浅析硫酸盐渍土松胀和盐胀工程性质对筑路的影响.  相似文献   

5.
目前国际上对于管道补偿装置的跑道形波纹管设计、制造、检验与验收未形成相应的标准及计算公式,文中利用有限元分析法计算跑道形波纹管的耐压、位移、疲劳等参数。文中通过有限元分析法模拟波纹管在各种工况下的使用情况,进行试验对比分析。波纹管承受内、外压时应力分布、变形情况,以及整体跑道形波纹管横向位移时应力分布、疲劳寿命均与工程应用较吻合。  相似文献   

6.
扁铲侧胀仪在轨道交通工程中的应用研究   总被引:1,自引:1,他引:1  
主要介绍扁铲侧胀试验仪器的特点,使用方法和数据整理计算公式,国外资料论述的扁铲侧胀试验经验公式及其在上海某工程中所利用的公式和求取的各种数据曲线情况。  相似文献   

7.
为研究流速对Ω形波纹管变形补偿与承载能力的影响,分别采用有限单元法和有限体积法对该波纹管内的空气流动进行数值模拟,计算出不同空气流速作用下的压力载荷;将该压力载荷作用于波纹管内壁面上,采用有限单元法和有限体积法得出不同空气流速作用下Ω形波纹管的轴向刚度和最大等效应力。结果表明:Ω形波纹管的变形补偿能力随流速的增大呈增强趋势,承载能力随流速的增大呈减弱趋势,且2种数值模拟方法计算结果的相对误差小于8%。  相似文献   

8.
章介绍了一种类似转筒的胀力盘在索道钢丝绳安装中的应用方法和操作要点,实践证明,采用胀力盘进行张力放索是一种安全可靠的放索方法。  相似文献   

9.
为分析加氢装置压缩机管段万向铰链型波纹膨胀节的波纹管开裂原因,对波纹管结构型式、波纹管材料性能进行了研究,通过对波纹管结构型式、材料改进,提高了万向铰链型膨胀节的波纹管使用性能,延长了波纹管的使用寿命,使系统中的补偿元件选型、敷设更合理,运行更安全。该设备已连续运行2年多,状况良好,说明改进措施安全可靠。  相似文献   

10.
通过对河西地区七瓜项目沿线盐渍土类型、分布特点、损坏特征及盐胀机理的分析,按照"防盐、隔盐与消胀"为一体处治思路,首次大面积采用反渗透脱盐净水技术、闷料及非盐砂砾土填料、"两布一膜"与未筛分碎石阻断层、消胀槽、桥涵台背回填、防排水及边坡防护等技术措施,提出了不同技术措施的作用机理、技术特点与施工质量控制要点,建立了河西地区盐渍土路基综合处治技术体系,为后期类似工程提供重要理论依据与技术支撑,具有积极行业示范效益与推广价值。  相似文献   

11.
Pedestrians as compared to vehicular traffic enjoy a high degree freedom of movement even in heavily congested areas. Consequently, there are more alternative links available to pedestrians between a given origin‐destination (O‐D) pair. This paper describes a study done by the University of Calgary to evaluate the factors affecting the choice of route on intra‐CBD trips or trips within the Central Business District (CBD).

An origin destination survey conducted in downtown Calgary, Alberta enabled the identification of the most significant factors influencing the choice. These factors were analyzed in relation to the physical characteristics of the location, personal characteristics of the trip maker and the type of the trip.

It appears that most people chose the shortest link and factors such as the level of congestion, safety or visual attractions were only secondary. This suggests that the length should be made a major consideration when planning and designing pedestrian links.  相似文献   

12.
This paper estimates the efficiencies and productivity changes of 12 international airports in the Asia-Pacific region based on data from 1998 to 2006. We apply stochastic frontier analysis (SFA) to compute efficiency estimates and use the Malmquist productivity index (MPI) to analyze productivity changes. We use the SFA model with a translog-type production function after testing the statistical hypotheses. According to the results of the SFA hypothesis tests, airports have experienced a technological regression; the deviations from the efficiency frontier are caused more by technical inefficiency than random noise. However, the inefficiency was found to decrease. The MPI reveals a declining trend resulting more from technological change than from efficiency change, with a decrease in inefficiency. Taken together, both the hypothesis tests and the MPI not only provide consistent conclusions, but also suggest that airports should concentrate on technological progress.  相似文献   

13.
波纹管应力分析研究进展   总被引:2,自引:0,他引:2  
评述了波纹管应力理论研究方法的进展情况,围绕解析法、工程近似法和数值法,对波纹管理论研究中的一些主要成果作了较详细的回顾和总结,对各种研究方法作出了评价,展望了亟待解决的一些问题。  相似文献   

14.
注汽管道承压能力评估和实物试验验证   总被引:2,自引:2,他引:0  
基于失效评估图技术对某注汽管道进行了承压能力评价,给出了管线在不同腐蚀壁厚情况下的极限承压能力和极限裂纹尺寸。并利用实物爆破试验验证了评价方法的安全性和有效性,通过对爆破断口进行宏观和微观分析,发现管段的开裂属于脆性开裂。  相似文献   

15.
天然气自动计量系统有多种组态软件,由于软件的不相通性,造成了计量系统数据采集的通用性差、数据传输与入库的时效性差、数据利用的可靠性低.结合各组态软件的实际情况,从设计上充分利用Oracle大数据处理能力以及Partition(分区表)的特性,实现历史数据的存储,应用WebService与COM+数据访问组件提供多层数据访问架构,采用OPC与DDE工业数据交换协议,实现了各站场计量数据的实时上传,为连续数据采集和实时监控提供了可能,节约了改造成本.  相似文献   

16.
殷爽 《地下工程与隧道》2011,(3):49-51,53,57
介绍了城市轨道交通工程中杂散电流不同的监测系统的构成,分析了集中式、分散式和智能型等监测系统的配置和功能,以及智能型实时在线监测系统的重要意义,为轨道交通工程杂散电流监测系统的选择与应用提供参考。  相似文献   

17.
明确埋地管道防腐保温层的技术评价标准,对埋地钢质管道的安全运行,延长管道使用寿命具有重要意义。为了对埋地管道防腐保温层做出有效评价,从间接检测与开挖检测2个方面,结合现场检测数据,提出了基于防腐保温层的电流衰减率、绝缘电阻率、质量状况与厚度的分级评价标准及基于4种评价指标的综合评判方法。工程实践表明,该评价标准对防腐保温层是否存在失效能做出有效判断。  相似文献   

18.
The main deficiency of most current modeling approaches to transportation can be identified as neglect of the integration of existing geographical knowledge in regard to the ex ante transport/land use modeling approaches, with its focus on territorial dynamics and theory development. This paper addresses this aspect of the problem by introducing a theoretical and methodological framework for the analysis of the interrelationship between land uses. The analysis attempts to determine to what extent the functional land use in a city can be considered an ordered pattern. The order sought does not rely on purely spatial configurations, but on the correlation of transportation and land use. The first section of this paper focuses on theoretical considerations. It stresses the fact that conventional approaches do not apply in the present context. It then suggests an alternative based on areas of influence and measured in terms of level of attractance of land uses. The second describes a procedure based on this alternative following the remarkable contribution of Hanjoul, Beguin and Thill. An application of this procedure to the analysis of Shanghai is then examined. Finally, an evaluation of the strategies for optimizing the interrelationship between land uses is presented. The paper concludes with a possible research agenda.  相似文献   

19.
原油乳状液的流变性是原油开采后在管道中输送的重要研究方面,为了更好地研究这一性质,采用电动搅拌机、偏光显微镜以及流变仪等仪器来测定不同含水率的原油乳状液在不同条件下的黏度,观测不同含水率的原油乳状液在偏光显微镜下的形态。并且分别对原油乳状液的黏度与含水率之间的关系以及与剪切速率之间的关系进行研究,初步确定了所测区块原油乳状液的转相点以及该区块原油乳状液的流变特性,为生产中的油气集输提供了理论依据。  相似文献   

20.
Reliability of travel modes was found to be the most important characteristic of transportation systems in several attitudinal investigations of individual travel behavior. This paper represents the first part of a research effort aimed at gaining a better understanding of the characteristics of reliability of transportation modes in urban travel. In this research, reliability characteristics are identified; their importance relative to each other is assessed, and an insight into possible structure of an objective reliability index is discussed. The research is based on perceived values of reliability, which were identified through a large attitudinal survey conducted in the Chicago metropolitan area.  相似文献   

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