A Multiscale Modeling and Updating Framework for Suspension Bridges Based on Modal Frequencies and Influence Lines

Aiming at obtaining an efficient and accurate multiscale model of suspension bridges, this paper innovatively proposed a multiscale modeling and updating framework based on measured modal frequencies and influence lines. In the first step, a multiscale model was created using the substructure method and the multipoint constraint method. The second step was to use the Gaussian process metamodel to perform multiscale model updating. For a suspension bridge with a flat steel box girder, a global model was created primarily using beam and truss elements, and the flat steel box girder of the critical section was finely modeled using shell elements. However, the refined model of the girder has many degrees of freedom. To reduce the computations, the substructure method was used to condense the refined model into a superelement. According to the multipoint constraint method based on deformation compatibility, the superelement and global model were coupled together to create a multiscale model. In terms of model updating, the theory of objective function construction based on the modal frequencies and influence lines was introduced first. Then, the trained Gaussian process model could replace the multiscale model to fit the relationship between the updated parameters and the objective function. Finally, the optimization algorithm was used to obtain the minimum value of the objective function. A case study of a suspension bridge was considered to demonstrate the effectiveness of the proposed framework. The measured deflection and strain influence lines of the bridge were obtained via a bridge moving vehicle test, and the modal frequencies of the bridge were obtained using environmental excitation. Using the proposed framework, the updated frequencies and influence lines were closer to the measured frequencies, and the computational efficiency was improved. Therefore, the proposed method could efficiently and accurately build a multiscale model of a suspension bridge.


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  • Accession Number: 01885482
  • Record Type: Publication
  • Files: TRIS, ASCE
  • Created Date: Jun 21 2023 5:10PM