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Dynamic Characterization of the Little Belt Suspension Bridge by Operational Modal Analysis

  • Silas S. Christensen
  • Michael S. Andersen
  • Anders Brandt
Conference paper
Part of the Conference Proceedings of the Society for Experimental Mechanics Series book series (CPSEMS)

Abstract

The (new) Little Belt Bridge, opened in 1970, is a Danish suspension bridge with largest span being 600 m, and a total length of 1700 m. During the design and construction phase, detailed analysis of the dynamic properties of the bridge were carried out both by hand calculations and by measurements on a scale model. Recently, the bridge was measured using a setup of 45 simultaneous responses, 30 vertical and 15 lateral, distributed over the main span. Operational modal analysis was carried out on the data set, and the first two vertical bending and torsional modes were compared to those of the model. It was found that the first vertical bending mode was 0.156 Hz, which is very near the frequency predicted by the original scale model. In total nine modes are reported, with frequencies from 0.156 to 0.808 Hz, and with damping values between 0.38% and 9.74%. This paper also demonstrates and discusses the use of inexpensive geophones and general measurement equipment for use in OMA applications based on the experience from this bridge measurement.

Keywords

Dynamic characterization Little belt suspension bridge Operational modal analysis Multi-reference Ibrahim time domain 

Notes

Acknowledgements

We would like to thank The Danish Road Directorate for their help during the measurement campaign. We would also greatly want to thank Hilde Husby Knustad for producing good measurements.

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Copyright information

© The Society for Experimental Mechanics, Inc. 2019

Authors and Affiliations

  • Silas S. Christensen
    • 1
  • Michael S. Andersen
    • 1
  • Anders Brandt
    • 1
  1. 1.Department of Technology and InnovationUniversity of Southern DenmarkOdense MDenmark

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