Multi-scale Finite Element Model Updating To Structural Health Monitoring

Due to the sensors install for structural health monitoring is limited, the details of all the key parts of the structure can not be monitored. Thus it is not enough to monitor during construction and operation just based on the collected information of structural health monitoring system. It is necessary to build the finite element model to simulate the real behavior of the structure, assist the structure health monitoring system to monitor the structure. Multi-scale finite element model using the macro element modeling to build the whole structure and the micro view element to build the local key structure, it is benefit the finite element model to obtain the information of the whole structure and local details. Using the steel structure of Zhuhai Opera House as the background, a multi-scale finite element model updating method is proposed f or the combination of the micro-scale modeling of the key nodes and the macro-scale modeling of the bar.The research on the micro-scale and multi-scale modeling of the key nodes of the structure is using the key node of Zhuhai Opera House. This part is the research of multi-scale modeling of welded box joints. The node’s meso-scale modeling is realizated by solving the problem of micro unit modeling at the intersection of the welded box type joint bar. Then the connection method of micro scale node model and macro scale beam element is studied. Using the multi-scale model of the small shell of the Zhuhai Opera House, The structural responses of the macro scale model and the m ulti- scale model are compared to verification of the node’s meso scale model and the rationality of the connection method with macro scale.To make the multi-scale finite element is more precise, updating method of multi-scale finite element model is proposed. Parameter model modification method is used, based on the structural parameters of sensitivity analysis to get structure fixed parameters. Latin hypercube experimental design is used to get structure sample parameters. Set up the response surface of the radial basis based on structure of different parameter variables and objective fu nction, and then verify whether the accuracy of the response surface model of the radial basis meets the requirements. Combining the genetic algorithm NSGA-II, carry the multi-objective optimized to the response surface of the radial basis function equation and get the optimal structure parameters to fix the multi-scale finite element model and verify the correction accuracy to the multi-scale model. Taking multi-scale finite element model with small shell structure as an example, through update combined of different parameters of the simulated structure of the multi-scale finite element model, verify the effectiveness of the multi-scale finite element model updating method which proposed in this article.For the large shell structure of Zhuhai Opera House structural health monitoring system, 18 welded box type steel joints were selected for the layout of strain sensor and building the meso scale model, then using the proposed method to realize the multi- scale finite element model of large shell steel structure. And then, the proposed modified finite element model is used to modify the model. Through the comparison and analysis of the static displacement response, the strain response and the dynamic response of the structure, the method can be effectively used for the construction of large steel structure finite element model for structural health monitoring is verified.