Research On Monitoirng Methods Of Dynamic Characteristics Of Large Suspension Birdge

With the rapid development of the socio-economic and science and technology,the scale of civil engineering structures are more and more large,the structures areincreasingly slim and lightweight, the function are more and more complex anddiverse. The bridge structures is just like this. The bridge structure plays an importantrole in the national economy and people’s lives, so the bridge structure in the processof service failure or sudden destruction will have socio-economic serious loss.Therefore modern engineering and technical characteristics is not only concernedabout the bridge design and construction technology, and more concerned about themaintenance and protection of the bridge structure. Traditional manual inspection ismore and more difficult to adapt to the bridge security needs, with the rapiddevelopment of modern sensor and information technology, large bridge structurehealth monitoring, safety assessment and residual life prediction problem more andmore scholars sought after.Suspension bridge softness larger cause it vulnerable to environmental incentivesand vibration, and therefore its security structure in the case of vibration it makessense. Health Monitoring System is a powerful weapon to ensure the safety of thestructure, research is imperative for the health monitoring of the dynamiccharacteristics of the bridge structure. The sensor system "eyes and ears" of the bridgestructural health monitoring system is an important part of the bridge healthmonitoring. Taking into account the factors of efficiency and economy, the need forthe optimization of the measuring point sensor laid on the bridge structure.The purpose and significance of long-span bridges monitoring the course of thedevelopment and application of review; a more detailed description of the dynamiccharacteristics of long-span bridges monitoring points to optimize the layout method,and compared; established Qingcaobei Yangtze River Bridge space dynamic analysismodel and its modal analysis, obtained by the modal and mode shapes of the model;structural unit modal displacement matrix or main-element decomposition, and thenafter the use of modal assurance criteria The Qingcaobei Yangtze River Bridge wasthe optimal allocation of the dynamic characteristics of monitoring sensors, the maincontent of the study are as follows:(1) paper describes the classification of the sensor and of the health monitoringsystem sensor based on the nature of the comparison and selection principles andoptimal allocation criteria, by comparison, selected MAC Standards the grass backKing suspension bridge sensor optimal allocation.(2) papers with Midas/Civil finite element analysis software to establish a thegrass back Yangtze River Bridge dynamic analysis space model, analysis of naturalvibration modes and frequencies.(3) First of all the main beam vertical modal displacement matrix QRdecomposition as the initial position, and then gradually add the measured pointoperations, the completion of the measurement points to optimize the allocation ofthese findings as. After the completion of the main beam measuring points,respectively the lateral vibration of the main cables and slings vibration measuring point configuration.