基于健康监测的连续刚构桥有限元模型确认(Ⅱ)——不确定性分析与模型精度评价

Finite element model validation of the continuous rigid frame bridge based on structural health monitoring——Part Ⅱ:Uncertainty analysis and evaluation of model accuracy

在下白石连续刚构桥基于响应面法的模型修正基础上,首先介绍模型确认过程试验/计算相关性分析的若干确认准则,分析模型与试验不确定性的来源;然后假定随机变量服从正态分布,采用蒙特卡罗有限元分析方法进行不确定性分析和量化,并评价模型的预测精度,实现连续刚构桥的有限元模型确认。结果表明:确认后的下白石大桥有限元模型能够很好地反映下白石大桥的真实状况,可供桥梁健康监测、损伤诊断和安全评估参考。

Based on an updated finite element（FE） model of the Xiabaishi rigid frame bridge,using the response surface method,the criteria for verification of the correlation analysis testing were introduced,and the sources of model and test uncertainties were analyzed.Assuming that the random variables obey the normal distribution,the Monte Carlo stochastic finite element（FE） method was employed to perform the analysis of uncertainties.The accuracy of the updated FE model was evaluated,and the FE model validation of the continuous rigid frame bridge with large spans realized.It can be concluded that the validated FE model of the Xiabaishi bridge can reflect the current conditions of the real bridge,and thus can be used as the basis for bridge health monitoring,damage detection and safety evaluation.