Parametric vibration and vibration reduction of cables in cable-stayed space latticed structure

Mechanical model and vibration equation of a cable in cable-stayed sparse latticed structure (CSLS) under external axial excitation were founded. Determination of the mass lumps and natural frequencies supplied by the space latticed structure (SLS) was analyzed. Multiple scales method (MSM) was introduced to analyze the characteristics of cable's parametric vibration, and the precise time-integration method (PTIM) was used to solve vibration equation. The vibration behavior of a cable is closely relative to the frequency ratio of the cable and SLS. The cable's parametric vibration caused by the external axial excitation easily occurs if the frequency ratio of the cable and SLS is in a certain range, and the cable's vibration amplitude varies greatly even if the initial disturbance supplied by SLS changes a little. Furthermore, the mechanical model and vibration equation of the composite cable system consisting of main cables and assistant cables were studied. The parametric analysis such as the pre-tension level and arrangement of the assistant cables was carried out. Due to the assistant cables, the single-cable vibration mode can be transferred to the global vibration mode, and the stiffness and damping of the cable system are enhanced. The natural frequencies of the composite cable system with the curve line arrangement of assistant cables are higher than those with the straight-line arrangement and the former is more effective than the latter on the cable's vibration suppression.     

潮漳高速:亭台楼阁存古韵 恰似湘桥好风流

正一路青峰隐隐,两岸亭台楼阁。韩江轻舟横渡,满池碧绿烟波。从东山一路向西,全长64公里的潮漳高速,带你一路驰骋,跨越地域界限,领略大美河山。广东省东山(闽粤界)至潮州古巷公路(简称"潮漳高速")于2017年12月28日正式通车,连接着福建、潮州两大文化古城精神脉络的潮漳高速,架起了时光穿梭的文化桥梁。风情土楼、青岚地质园、湘子桥、凤凰塔、牌坊街……潮州城外,横卧韩江之上的潮漳高速,像一把悠扬的古琴,日夜传唱别样潮州的建造技巧之奇与秀美山川之趣。     

Wind Vibration Study of Long-span Steel Arch Structure of Beijing Capital International Airport

IntroductionThe long-span light-weight steel arch struc-tures have been widely used in the world due to itsbeautiful shape and reasonable mechanical charac-teristics. With the development of the computa-tional theory, the steel arch span becomes longerand longer. So, the wind loads become the majoror even dominant loads applied on steel arch struc-tural system[1~3]. The distress and damage willprobably occur in the structure, because of thelong term wind-induced vibration.1 Structural Wind-in…     

南京地铁2号线无线车载台维护应用

无线车载台是专网无线集群系统的重要组成部分和高频使用终端,用于实现司机与控制中心调度、车站人员之间的通信,为车辆调度作业提供高效可靠的无线语音及数据服务控制。简单介绍南京地铁2号线无线车载台的硬件组成,重点阐述无线车载台的日常维护、检修模式、检修周期以及常见故障排查。     

The Stability Study of Globe Transportation Center of Beijing Capital International Airport

Introduction For decades, the long-span space structurehave been widely used in the world. The light steearch structural system also becomes popular, because of its beautiful shape, reasonable structurand low cost[1]. With the application of higstrength structural steel and advanced constructiotechniques, however, the flange plates and web oa steel arch system have become thinner and thinner than before, which makes the structural stability more serious, especially for the long-span thiwall va…     

离心钢管混凝土扭转性能有限元分析方法研究

通过采用ANSYS中摩擦接触中的面-面接触单元对离心钢管混凝土构件进行数值模拟。分析中考虑了材料非线性和接触非线性,研究不同的参数取值对构件扭转性能的影响,得到最佳的参数取值。通过试算得到的接触参数,对离心钢管混凝土构件进行数值分析,得到构件的抗扭承载力,并与试验进行了对比,结果较吻合。     

车载视频系统及其应用维护

车载视频系统是现代城市轨道交通乘客信息系统的重要组成部分。主要介绍车载视频系统组成及工作方式,重点阐述车载视频系统的日常维护、检修模式、检修周期以及故障排查。     

富翅门大桥设计分析

以舟山市富翅门大桥-双塔结合梁斜拉桥为工程实例,从双塔结合梁斜拉桥的构造特点入手,通过对双塔结合梁斜拉桥、双塔混凝土梁斜拉桥及独塔钢箱梁斜拉桥三个桥梁方案的比选和技术经济比较,确定双塔结合梁斜拉桥为推荐方案.最终根据确定的桥型,采用有限元对其进行了细部设计和计算研究.给出有关结论和建议,有关经验可供相关专业人员参考.     

南京地铁通信无线集群系统位置更新异常研究

位置更新,即自动转组功能,是无线集群通信系统的重要功能之一,它是实现调度指挥权顺利移交的重要手段。自动位置更新功能失败直接影响调度员次日使用信号楼调度台指挥列车出库。以南京地铁2号线无线系统为例,阐述位置更新的意义、原理和流程,并结合其运营,详细介绍导致位置更新失败的主要原因——错误回库。