Identification of Modal Frequencies From the Pre-Stressed Concrete Bridge Dynamic Response to Different Sources of Dynamic Excitation

https://doi.org/10.26552/com.C.2018.4.63-68

  • Jozef Melcer
  • Jan Kortis
  • Lubos Daniel
  • Peter Fabo
Keywords: dynamic excitation, modal frequencies, free vibrations, moving load, FRF function

Abstract

The natural frequencies and mode shapes are unique characteristics of each mechanical structure. Their prediction is a crucial part of each dynamic experimental measurement. However, the proper identification of higher natural frequencies and mode shapes can be a problem, especially for big structures such as bridges. The reason is the need to excite the bridge in such a way that it responds in a free-vibrations mode shape. This paper describes three various sources of excitations, which are used to identify the modal characteristics of the pre-stressed concrete bridge. The impulse excitation, traffic load and ambient vibration are used and analyzed. In the case of the loading by a force impulse, modal shapes are also obtained. The study shows that the intensity and kind of the excitation has a noticeable impact on identification of modal frequencies. Finally, the results of the experimental measurements are used to calibrate the numerical model.

Author Biographies

Jozef Melcer

Department of Structural Mechanics and Applied Mathematics, Faculty of Civil Engineering, University of Zilina, Slovakia

Jan Kortis

Research Center, University of Zilina, Slovakia

Lubos Daniel

Research Center, University of Zilina, Slovakia

Peter Fabo

Research Center, University of Zilina, Slovakia

Published
2018-12-31
How to Cite
Melcer, J., Kortis, J., Daniel, L., & Fabo, P. (2018). Identification of Modal Frequencies From the Pre-Stressed Concrete Bridge Dynamic Response to Different Sources of Dynamic Excitation. Communications - Scientific Letters of the University of Zilina, 20(4), 63-68. https://doi.org/10.26552/com.C.2018.4.63-68
Section
Civil Engineering in Transport