基于贝叶斯信息融合的岸桥有限元模型修正研究

Finite Element Model Updating of Quayside Container Crane Based on Bayesian and Information Fusion Theory

为建立精确的岸桥有限元模型,研究了基于贝叶斯信息融合的模型修正方法.通过方差分析,确定待修正参数,利用中心复合试验设计获取样本点,根据有限元计算结果与实测的结果残差为目标函数获得响应样本.拟合样本点和响应样本值构建二阶多项式响应面模型,并检验响应面模型的精度.基于贝叶斯理论更新融合系数来优化响应面参数,从而获得修正模型.以宁波大榭3号岸桥为工程背景,对比修正后的模态频率和实测频率,最大频率相对误差不超过5%,进而验证了基于贝叶斯信息融合的动力学有限元模型修正方法的有效性.修正后的有限元模型可进一步应用于岸桥的健康监测和安全评估.

A new finite element（FE） model updating method based on information fusion and Bayesian theory was proposed to construct an accurate quayside container crane FE model. By using variance analysis to determine the parameters and then applying central composite experimental design to obtain sample points, the residuals between finite element and tested results were considered as an optimization objective to acquire sample response values. Subsequently, the accuracy of the second-order polynomial response surface model constructed by fitting sample points and corresponding response values was investigated. The fusion coefficient for optimizing the response surface parameters eventually was updated based upon Bayesian theory, resulting in a calibrated FE model. Comparing the updated modal frequencies with that tested on a practical engineering structure, i.e., Ningbo Daxie 3 rd quayside container crane, it is found that the maximum relative error of frequencies was less than 5%, which verified the effectiveness of this proposed model updating method. The updated FE model can be further applied to structural health monitoring（SHM） of the quayside container crane type of structures.