The Kurt Ruths Prize, which has been awarded annually since 1989, is endowed with 12,000 euros. It honours outstanding scientific achievements in the fields of architecture, civil and environmental engineering and chemistry and is awarded to early-career researchers at TU Darmstadt who have distinguished themselves with outstanding dissertations. The prize is named after Kurt Ruths, the long-standing Chairman of the Braas Group Management Board.

This year, the Kurt Ruths Prize will be awarded in equal parts to the chemist Dr Leon Schumacher and the civil engineer Dr Steven R. Lorenzen.

In his dissertation, Dr Steven R. Lorenzen dealt with methods for monitoring and extending the service life of railway bridges with the help of ‘drive-by monitoring’. Monitoring bridges with permanently installed devices is time-consuming and costly. With ‘drive-by monitoring’, trains are instead equipped with sensors that can take measurements every time they cross. This allows the entire network to be monitored with just a few trains. A particular challenge here is the often short spans of the bridges combined with the high speed of the trains. Lorenzen was able to solve this problem with the help of structural dynamics and, as part of his doctorate, developed a process in which acceleration sensors attached to the train determine its resonance frequency as it crosses a bridge.

Bridges are not rigid, but structures that can move or vibrate due to their design. This free oscillation is called natural frequency. If a force with the same frequency acts on the bridge from outside – for example by a train – resonance can occur and the vibrations intensify, which in the worst case can lead to collapse. Thanks to the new method, which can now be used to determine the resonance frequencies of bridges, the dangerous ‘resonance crossings’ can be avoided, for example by minimising speed adjustments. This significantly increases the service life of bridges.

‘In view of the poor condition of many bridges in Germany and the stresses caused by new types of trains, innovative methods for monitoring and extending the service life of these bridges are necessary and highly relevant to society,’ says the head of the Institute of Structural Analysis and Design, Professor Clemens Hübler from the Department of Civil and Environmental Engineering. “What also characterises Steven R. Lorenzen is not just pure achievement, but the ability and desire to contribute to science and university operations beyond that. In my estimation, Dr Lorenzen will make significant contributions to the further development of structural monitoring and structural dynamics in the future through his creativity and performance.”