【作者】 王洋；

【导师】 朱劲松；

【作者基本信息】 天津大学 ， 桥梁与隧道工程， 2017， 硕士

【摘要】 桥梁结构作为国家交通运输系统的重要组成部分,承担着国民经济发展的重任,对国家建设发展的高速稳定增长起着重大的作用。桥梁结构的正常运行是发挥其作用的前提,日益增长的交通量和对超重车的管制不严时刻威胁着桥梁结构的健康,一旦桥梁的受损程度在短时间内迅速累积,突发性灾难事故将不可避免,严重损害着社会主义和谐社会的发展,给人民的财产安全造成重大威胁。故此,桥梁结构的损伤预警,已经成为重大桥梁结构健康监测中的重要环节之一。本文基于冗余度理论和有限元分析,提出大跨度悬索桥的预警分析方法,为运营中的大型悬索桥损伤预警提供了理论依据。本文主要工作如下:1、为快速精准地求得悬索桥的成桥线形,提出结合主缆线形解析法与有限元分析的计算方法,以某在建大跨度悬索桥为研究对象,利用MATLAB程序编译迭代计算程序,并与MIDAS CIVIL、ANSYS找形程序的计算结果相对比。2、提出了基于吊索重要性系数的悬索桥冗余度分析方法,利用悬索桥吊索损伤前后整体结构的应变能变化,确定吊索的重要性系数,对各类最不利损伤状况的悬索桥冗余度进行定量计算,同时分析损伤结构的应力增量。分析表明,越靠近跨中的吊索失效对悬索桥的冗余度影响越大,认为当冗余度小于0.201时,桥梁的应力变化巨大,且有发生整体倒塌的趋势,不再适于继续承受荷载。3、以悬索桥的钢-混结合梁体系为研究对象,建立悬索桥多尺度有限元模型,对重要性系数较大的吊索附近主梁局部梁段进行精细化建模,确定车载作用下吊索失效对附近加劲梁应力的变化,分析了吊索失效对悬索桥钢-混结合梁局部受力的影响。结果表明,断裂吊索的加劲梁局部区域的安全性反而提高,而相邻吊索附近的梁段出现极大的拉应力,对于桥面板已达到混凝土的极限抗拉应力,混凝土桥面板出现拉溃。更多还原

【Abstract】 As an important part of national transportation system,bridge structure bears the important task of national economic development,and plays a significant role in high-speed steady growth of the country’s and development.To make sure bridges give full playing to the roll,bridge structure should keep the normal operation.However,growing traffic and overload cars regulation is lax moment threatening the health of bridge structure,once the bridge damage accumulating rapidly in a short time,the sudden disaster will be inevitable,and bringing serious damage to the development of the socialist harmonious society,caused a major threat to people’s property security.Therefore,bridge structure damage alarming,has become one of the important link of major bridge structure health monitoring.This thesis is based on redundancy theory and finite element analysis,the early warning analysis of long span suspension bridges is proposed,provided a theoretical basis for the operation of large suspension bridge damage early-warning.In this thesis,main work is as follows:1.In order to realize fast accurately obtained suspension bridge into the bridge linear,putted forward in combination with the cable shape analytic method and finite element analysis and the calculation method of taking a long-span suspension bridge under construction as the research object,using the MATLAB program compiled iterative calculation,and contrast calculated results to MIDAS CIVIL and find form program based on ANSYS.2.The importance coefficient based on the sling suspension bridge redundancy analysis method is putted forward,using suspension bridge cable strain energy of the whole structure,determine the importance coefficient of sling,for all kinds of the most unfavorable damaged conditions of redundancy for quantitative calculation of suspension bridges,at the same time analyzed damage of the structure of the stress increment.The analysis results show that the closer the redundancy of long-span suspension bridge across the sling failure effect,the greater the thought when redundancy is less than 0.201,the stress variation in the bridge is huge,and the trend of the overall collapse,no longer fit to continue to bear the load.3.With suspension bridge steel-mix combined beam system as the research object,established a multi-scale finite element model of suspension bridges,the importance coefficient is larger near the line of main girder segment of the local beam refined modeling,determine the action of stiffening stress under the car sling failure,analyzes the failure of suspension bridge steel sling-mixed combining beam local stress.Results show that the fracture of the sling stiffening girder and the security of local area instead of improving,and the adjacent line near the beam section in great tension stress,the bridge panel has reached the limit tensile stress of concrete,concrete bridge panel in collapse.更多还原