Modal Extension And Model Updating Of Long Span Arch Bridge With Kriging Method

The finite element(FE)model updating of the structure is one of the important contents to predict its response under external load,evaluate the structural state,and establish a baseline model for bridge structure health monitoring.The FE model is usually built according to the design drawings,which contains a large number of idealized assumptions and simplifications,while the complicated construction process of the bridge structure will lead to changes in structure dimensions and material parameters.Therefore,there is a mechanical properties deviation between the actual structure and the FE model,and the FE analysis model updating is urgently needed.This paper takes Zhuhai Hengqin Second Bridge as the project background.The main contents of the study are as follows:(1)Introduce the principle of Kriging method briefly.Based on the principle of Kriging method,a program of deck elevation fitting analysis was made combined with the real engineering problem.The interpolation effects of linear interpolation,cubic interpolation and Kriging interpolation method are analyzed and compared,and the influence of different correlation parameters ? on the interpolation results is analyzed.(2)A modal expansion method of bridge measurement model with the Kriging model was proposed.The feasibility of the modal expansion method proposed in this paper was verified by a simply supported beam example.(3)The modal test and data analysis were carried out on the Hengqin Second Bridge,and the modal expansion of the Hengqin Second Bridge was carried out using the measured modal data.(4)One FE model updating method is proposed based on the natural frequency,and a model updating method with higher correction accuracy was proposed based on the natural frequency and the modal expansion mode.The influence of the asymmetry of material parameters is took into account through this method.The natural frequency of updated model is closer to the measured results,and the updated material parameters are meaningful in the real engineering project.The effectiveness of the proposed method is verified by a model updating of the Hengqiao Second Bridge.