失效非线性相关的桥梁截面可靠性Vine-Copula数据融合

Data Fusion about Vine-Copula for Bridge Section Reliability Considering Nonlinear Correlation of Failure Modes

摘要:

为合理融合健康监测数据分析在役桥梁截面可靠性，首先应用桥梁截面多个监测点的极值应力数据，建立监测变量非线性相关的VineCopula模型，实现极值应力数据的融合分析；然后结合多个监测点的功能函数，进行桥梁截面失效模式非线性相关的VineCopula建模分析，并融合一次二阶矩(FOSM)方法，分析失效非线性相关的桥梁截面可靠性；最后进行了在役桥梁截面监测数据的验证分析.研究表明,考虑失效模式非线性相关性所得桥梁截面可靠性较不考虑失效模式相关性所得结果小，说明不考虑失效模式相关性所得结果偏保守.

关键词:桥梁; 截面; 非线性相关性; VineCopula模型; 一次二阶矩(FOSM)方法; 可靠性分析

Abstract:

Bridge section reliability analysis method is reasonably carried on with the fusion of structural health monitoring data. Firstly, the vinecopula models considering the nonlinear correlation of multiple monitored variables were established based on the extreme stress data at the multiple monitored points of bridge section, which make the extreme stress data fusion achieved. Secondly, the vine copula models considering the nonlinear correlation of failure modes about bridge section were built with the performance functions about the multiple monitored points, further, through combining the built vine copula models with first order second moment (FOSM) method, the bridge section reliability considering the nonlinear correlation of failure modes was analyzed. Finally, the monitored data of an existing bridge was provided to illustrate the proposed model and method. The results show that the obtained bridge section reliability with considering the nonlinear correlation of failure modes is bigger than that without considering the correlation of failure modes. It is illustrated that the obtained results without considering the correlation of failure modes are conservative.

Key words:bridge; girder section; nonlinear correlation; VineCopula model; first order second moment (FOSM) method; reliability analysis