Experimental modal analysis of diagonal members

Michal Venglar1 , Milan Sokol2

1, 2Slovak University of Technology in Bratislava, Faculty of Civil Engineering, Bratislava, Slovak Republic

1Corresponding author

Vibroengineering PROCEDIA, Vol. 23, 2019, p. 110-114. https://doi.org/10.21595/vp.2019.20671
Received 13 March 2019; accepted 21 March 2019; published 25 April 2019

Copyright © 2019 Michal Venglar, et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Creative Commons License

Truss bridges are integral part of the transport network, mainly railroads and partially road bridges. The investigated bridge is located in the western part of Slovakia, and it crosses the Vah River. Density of traffic on the bridge is not so high, so the bridge is accessible for repeating dynamic measurements. Many load situations were simulated. Among of them also a case, where one diagonal member was excited by an electromagnetic exciter during the measurements and the influence on other diagonals have been also analyzed. Results of dynamic measurements are shown in this paper in comparison to analytical solution and to FEM calculations.

Graphical Abstract

  • Artificial excitation of one diagonal member can excite another diagonal member to the resonant frequency
  • The FEM model prepared by using mainly BEAM elements can be used for comparison of global mode-shapes
  • On the other hand, neglecting structural details can lead to a mismatch of experimentally obtained and calculated natural frequency

Keywords: truss bridge, NDT testing, artificial exciter, natural frequency, local mode-shape.


This paper was supported by the Slovak Research and Development Agency (SRDA), i.e. a grant from research program No. APVV-0236-12. It was also supported by VEGA No. 1/0749/19.


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