基于健康监测的平胜大桥钢箱梁细节疲劳可靠度研究

发布时间：2018-05-26 01:33

本文选题：疲劳可靠度 + 钢箱梁　；参考：《长沙理工大学》2014年硕士论文

【摘要】：在运营期的反复车辆荷载作用下,桥梁结构面临着疲劳损伤的问题。考虑到结构参数与荷载的随机性,桥梁结构的疲劳破坏具有一定的概率特征。作为国内最大跨度的独塔自锚式悬索桥—平胜大桥钢梁箱结构正交异性桥面板的疲劳可靠性值得进行安全评估。由于平胜大桥已经安装健康监测系统,该系统能够提供钢桥面板的疲劳应力数据,这为平胜大桥钢箱梁桥面板的疲劳可靠度评估提供了有利条件。为了研究大跨度独塔自锚式悬索桥的钢箱梁构造细节在随机荷载作用下的疲劳可靠度,以国内最大跨度的独塔自锚式悬索桥—平胜大桥为工程背景,在健康监测应力数据的基础上采用疲劳可靠度理论对其钢箱梁桥面板构造细节疲劳性能进行了研究。首先基于Palmegren-Miner线性累积损伤准则建立了疲劳可靠度的极限状态方程,其次基于平胜大桥健康监测的典型应力和温度数据建立了疲劳应力谱,最后分析了不同交通量增长系数下平胜大桥钢箱梁细节疲劳可靠度。论文的主要研究内容与研究成果包括：(1)简述了钢结构疲劳可靠度理论与相应的分析方法。以S-N曲线和Miner线性损伤准则为基础,建立疲劳损伤的极限状态方程,并给出疲劳可靠度评估的关键步骤。主要从结构可靠度理论及其分析方法、钢箱梁的疲劳性能和疲劳可靠度评估方法三个方面展开讨论。针对疲劳可靠度分析的极限状态表达式,本文重点介绍了结构可靠度分析中的JC方法,该方法为后文对疲劳可靠指标计算奠定基础。从钢箱梁结构的疲劳性能入手,建立钢结构疲劳失效的极限状态方程,对3个重要的疲劳失效准则进行了讨论。从目前疲劳可靠度评估方法的综述中给出本文疲劳可靠度评估的流程图。(2)针对平胜大桥健康监测系统的疲劳应力进行了统计分析。介绍了平胜大桥的健康监测系统,对平胜大桥健康监测的整个系统和传感器布置两个方面进行了描述。通过引入雨流计数法和谷峰方法两种方法介绍了监测应力数据提取与分析方法。针对实测数据进行了处理分析,提取了应力循环及循环次数,并对多组应力数据进行了统计分析。建立了平胜大桥疲劳荷载效应的概率模型。采用K-S检验获取Seq和Nd的概率分布类型和分布特征值。由分析结果可知：中跨跨中BCV-5-2传感器所在位置的疲劳损伤最大,q的均值为5.31MPa,标准差为1.58MPa,对应的日损伤值为1.3×10-6。(3)平胜大桥的疲劳可靠度分析结果表明：平胜大桥钢箱梁的应力数据具有低应力和高循环的特点,可基于Erucode规范对构造细节和低应力幅值的处理方法和等效损伤得出等效应力幅值。平胜大桥钢箱梁细节疲劳可靠指标为5.274；当交通量增长系数分别为0、0.1和0.2时,平胜大桥钢箱梁细节疲劳可靠指标在100年后分别下降为2.305、1.681和1.395；交通量增长系数在前期对疲劳可靠指标的影响较小,而后期对疲劳可靠指标的影响较大。
[Abstract]:Under the operation period of repeated vehicle load, the bridge structure faces the problem of fatigue damage. Considering the randomness of the structure parameters and load, the fatigue failure of the bridge structure has certain probability characteristics. As the largest single tower self anchored suspension bridge in China - the fatigue of the orthotropic bridge deck of the steel beam box structure of the Ping Sheng Bridge Reliability is worthy of safety assessment. As the Ping Sheng bridge has installed health monitoring system, the system can provide fatigue stress data of the steel bridge deck, which provides favorable conditions for the fatigue reliability evaluation of the steel box girder bridge deck of the bridge. The fatigue reliability under the load is taken as the engineering background of the largest single tower self anchored suspension bridge in China. On the basis of the stress data of health monitoring, the fatigue reliability of the steel box girder bridge panel is studied by using the fatigue reliability theory. First, the Palmegren-Miner linear cumulative damage criterion is established. The ultimate state equation of fatigue reliability is obtained. Secondly, based on the typical stress and temperature data of the health monitoring of the bridge, the fatigue stress spectrum is established. Finally, the detailed fatigue reliability of the steel box girder of Ping Sheng Bridge under different traffic volume growth coefficients is analyzed. The main research contents and research results of this paper include: (1) the fatigue of steel structure is briefly described. Based on S-N curve and Miner linear damage criterion, the ultimate state equation of fatigue damage is established, and the key steps of fatigue reliability evaluation are given. Three aspects are discussed mainly from the structure reliability theory and its analysis method, the fatigue performance and the fatigue reliability evaluation method of the steel box girder. In view of the limit state expression of fatigue reliability analysis, this paper mainly introduces the JC method in structural reliability analysis. This method lays the foundation for the calculation of fatigue reliability index in the later text. Starting with the fatigue performance of steel box girder structure, the ultimate state equation of fatigue failure of steel structure is established, and 3 important fatigue failure criteria are entered. The flow chart of fatigue reliability evaluation in this paper is given from the summary of the current fatigue reliability evaluation methods. (2) the fatigue stress of the health monitoring system of the Ping Sheng Bridge is statistically analyzed. The health monitoring system of the Ping Sheng Bridge is introduced, and the whole system and sensor layout of the health monitoring of the bridge are two aspects. The method of monitoring stress data extraction and analysis is introduced by introducing two methods of rain flow counting and Gu Feng method. In view of the measured data, the stress cycle and cycle times are extracted, and the multi group stress data are analyzed. The probability model of the fatigue load effect of the Ping Sheng Bridge is established. The probability distribution type and distribution characteristic value of Seq and Nd are obtained by K-S test. From the analysis results, the fatigue damage of the middle span and mid span BCV-5-2 sensor is the largest, the mean value of Q is 5.31MPa, the standard deviation is 1.58MPa, and the corresponding daily damage value of 1.3 x 10-6. (3) Ping Sheng Bridge is analyzed by the fatigue reliability analysis of the bridge of Ping Sheng Bridge. The stress data of the box girder has the characteristics of low stress and high cycle, which can be based on the Erucode specification for the treatment of structural details and low stress amplitude and equivalent damage amplitude. The reliability index of the steel box girder is 5.274. When the traffic growth coefficient is divided into 0,0.1 and 0.2, the details of the steel box girder of the Ping Sheng Bridge are detailed. The reliability index of fatigue is reduced to 2.305,1.681 and 1.395 after 100 years, and the increase coefficient of traffic volume has little influence on the fatigue reliability index in the early stage, and the latter has a great influence on the reliability index of fatigue.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.4

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