Natural Frequency of Bridges

Since the speed of trains in Europe has increased considerably in recent decades, resonance effects may cause problems with regard to the dynamic behavior of the structures of railway bridges.

Measurements on several existing objects have shown that the constructed bridges have higher natural frequencies and thus higher stiffnesses, compared to a calculation with the usual static values. Reasons for this are, for example, the increase in the modulus of elasticity with the age, the real cross-section properties of a structure, contribution of the edge beams, continuous rails, inaccuracies in the mass assumption, foundations of frame bridges, and the continuous ballast bed stiffness.

Author	Markus Pfennig
University	University of Applied Sciences Campus Vienna, Austria

On the basis of three bridge objects, for which the measurement exercise has already been carried out, the objective of this thesis was to investigate how certain parameters should be applied in order to obtain a computer model that is as close to reality as possible. This would have simulated the "actual stiffness of the structure," so it would be possible to make realistic assessments.

Natural Frequency of Bridges

"First of all, I would like to thank Dlubal Software for providing me with the RSTAB and RFEM product families free of charge to process my thesis, which made the entire work easier for me and allowed me to gain new knowledge in terms of structural calculations."

Downloads

Table of Contents (PDF - 132.6 kB)

132.64 KB

;