Extending the Service Life of Railway Bridges

METHODS FOR EXTENDING THE SERVICE LIFE OF RAILWAY BRIDGES USING ACTIVE ELEMENTS

Structural oscillations constitute the main influence on the technical design of structures where the limiting factor is mechanical strength rather than stiffness. Railway bridges, especially those made of steel, commonly fall under this category. Here, oscillations are induced mainly by rail traffic. The excitation frequencies, which depend mostly on axle distances and speeds, can vary significantly. Research has suggested that these forced oscillations during a train passing usually exhibit much higher amplitudes than the following free oscillations. Therefore, in order to effectively decrease material fatigue and extend the service life of these bridges, oscillations need to be reduced over a large frequency band.

In contrast to tuned mass dampers, which are the commonly used solution to dampen bridge vibrations, this project explores the use of hydraulic actuators to apply external forces on the bridge. This active approach is more flexible, allows for static compensation and enables the reduction of oscillations over a larger frequency band.

The goal of this project is to deliver a proof-of-concept for retrofittable active oscillation reduction at railway bridges. To this end, a model-based control algorithm for distributed dynamic disturbance compensation using boundary control is developed. The methods are validated and tested at a steel trough bridge and compared to state-of-the-art systems with regards to effectiveness, complexity and robustness.

PRINCIPAL INVESTIGATOR

Prof. Dr.-Ing. habil. Dr. h.c. Oliver Sawodny
Institute for System Dynamics (ISYS), University of Stuttgart

RESEARCHER
Kilian Gröber (ISYS)

PARTNERS
IBB – Institute for Structural Mechanics
MAURER SE
Liebherr-Components Kirchdorf GmbH
DB InfraGO AG
German Centre for Rail Traffic Research at the Federal Railway Authority

FUNDING
German Research Foundation (DFG)