大跨斜拱桥结构健康监测系统的设计与研发

发布时间：2018-01-07 14:26

本文关键词：大跨斜拱桥结构健康监测系统的设计与研发　出处：《大连理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：近十年来,随着国民经济的发展,桥梁建设得到跨越式发展,一座座大跨桥梁结构如雨后春笋般出现在我国各地。桥梁建成以后,由于车辆荷载和环境侵蚀等因素影响,将不可避免地发生累积损伤和疲劳破坏。结构健康监测系统通过采集结构与环境信息,来判断结构的安全状况,为解决大跨桥梁的安全服役问题打开了一个新的突破口。沈阳伯官大桥是我国首座六跨中承式飘带形提篮斜拱桥,为确保该桥在施工及服役期间的安全,引入结构健康监测系统对其进行长期的实时监测。本文以沈阳伯官大桥为工程依托,对大跨拱桥在施工及服役期间的健康监测技术进行了研究。主要工作内容及结论如下： (1)该桥结构形式新颖,受力复杂,在分析了其结构特点的基础上,提出了该桥的监测需求。采用大型通用有限元软件MIDAS/Civil建立了该桥的精细化三维有限元模型,使用多种单元和边界约束较好的模拟了大桥的结构特点,基于多种荷载组合对大桥进行了详细的数值模拟计算,分析得到了大桥的关键受力构件和薄弱部位,为传感器合理选型及优化布设奠定了基础,同时为监测参量阂值的确定提供了参考依据。 (2)基于本系统的多功能需求,设计了系统的总体架构,由传感器子系统、数据采集与传输子系统、数据管理子系统及结构状况评估子系统构成。根据数值模拟结果,提出了本系统的主要监测项目,包括工作环境监测、结构静态响应监测及结构动力特性监测三类。然后依据传感器选型原则,在分析了各类型传感器性能特点的基础上,选出了本系统采用的传感器类型及性能指标,为健康监测系统的具体实现奠定了坚实的基础。 (3)结合该桥的结构特点及数值模拟结果,确定了系统的监测方案和传感器布设方案,详细介绍了系统实现过程中的测点选择及传感器的保护措施。为满足传感器数量多、分布广、信号测量精度和同步性要求高的需求,基于NI CompactRIO平台自主研发了一套分布式结构健康监测数据同步采集仪器,实现了多类型传感器及多终端设备之间的精准同步采集。考虑到本系统传感器布设数量大,数据类型繁多,为保证整套系统的运转效率,采用SQL Server2000作为中心数据库,实现了数据的有效管理及存储。最后基于LabVIEW软件平台集成了本监测系统,该系统成功实现了数据自动存储、自动生成系统报表以及多方式自动预警等功能。 (4)利用光纤光栅传感器对施工过程及成桥后的拱座处应力进行了初步监测。监测结果表明：施工过程中各测点应力幅度随施工的推进变化较大,成桥后,应力变化幅度较小,桥梁受力开始趋于稳定。在应力监测中,温度效应对监测结果影响较大,因此必须进行温度补偿以消除温度的影响。
[Abstract]:In the past ten years, with the development of the national economy, the bridge construction has been developed by leaps and bounds. Due to the influence of vehicle load and environmental erosion, cumulative damage and fatigue damage will inevitably occur. The structure health monitoring system can judge the safety status of the structure by collecting information of structure and environment. In order to solve the problem of safety service of long-span bridge, a new breakthrough has been opened. Shenyang Boguan Bridge is the first six-span through ribbon inclined arch bridge in China, in order to ensure the safety of the bridge during construction and service. The structural health monitoring system is introduced to carry out long-term real-time monitoring. This paper is based on the Boguan Bridge in Shenyang. The health monitoring technology of long span arch bridge during construction and service is studied. The main contents and conclusions are as follows: 1) the structure of the bridge is novel and the force is complex. Based on the analysis of the structural characteristics of the bridge. The monitoring requirements of the bridge are put forward, and the fine three-dimensional finite element model of the bridge is established by using the large-scale general finite element software MIDAS/Civil. The structural characteristics of the bridge are simulated with various elements and boundary constraints. Based on the combination of various loads, the detailed numerical simulation of the bridge is carried out, and the key components and weak parts of the bridge are obtained. It lays a foundation for the reasonable selection and optimization of sensor layout, and provides a reference for the determination of the threshold value of the monitoring parameters. Based on the multifunctional requirements of the system, the overall architecture of the system is designed, which consists of sensor subsystem, data acquisition and transmission subsystem. According to the results of numerical simulation, the main monitoring items of the system, including working environment monitoring, are put forward. There are three kinds of structural static response monitoring and structural dynamic characteristic monitoring. Then, according to the principle of sensor selection, the performance characteristics of each type of sensor are analyzed. The sensor types and performance indexes used in the system are selected, which lays a solid foundation for the realization of the health monitoring system. 3) combined with the structural characteristics of the bridge and the results of numerical simulation, the monitoring scheme and sensor layout scheme of the system are determined. In order to meet the needs of large number of sensors, wide distribution, high precision and synchronization of signal measurement, the selection of measuring points and the protection measures of sensors are introduced in detail. Based on NI CompactRIO platform, a set of distributed health monitoring data synchronous acquisition instrument is developed. The accurate synchronous acquisition between multi-type sensors and multi-terminal devices is realized. Considering the large number of sensors and a wide variety of data types in this system, to ensure the operation efficiency of the whole system. SQL Server2000 is used as the central database to realize the effective management and storage of the data. Finally, the monitoring system is integrated based on the LabVIEW software platform. The system successfully realizes the functions of automatic data storage, automatic generation of system reports and multi-mode automatic warning. (4) the stress of the arch base after completion of the bridge is preliminarily monitored by using the fiber grating sensor. The monitoring results show that the stress amplitude of each measuring point changes greatly with the advance of the construction during the construction process, and after the completion of the bridge. In the stress monitoring, temperature effect has a great influence on the monitoring results, so temperature compensation must be carried out to eliminate the influence of temperature.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U446

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