Composite steel–concrete bridges are increasingly exposed to cyclic loading due to growing heavy traffic volumes, which may lead to fatigue damage in headed stud shear connectors. Owing to the pronounced notch effect at the weld toe, these connectors are particularly susceptible to fatigue cracking. The proposed research project experimentally investigates components recovered from the “Talbrücke Rahmede” to assess the fatigue performance of existing highway bridges. The primary focus is on fatigue testing of headed studs with different levels of pre-existing damage to evaluate their degree of damage and remaining service life. In parallel, ultrasonic testing is conducted during the experiments to detect fatigue cracks developing at the weld. Finally, the results are analysed and evaluated in the context of current design rules and recent research findings.

University of Stuttgart
Institute of Structural Design and Material Testing Institute Stuttgart
Univ. Prof. Dr. sc. techn. habil. Markus Knobloch
Univ.-Prof. Dr.-Ing. Jan Hofmann
Dr.- Ing. Thilo Fröhlich (Researcher MPA)
Maximilian Ziwes, M.Sc. (Researcher KE)

Research project commissioned by the Federal Republic of Germany, represented by the Federal Ministry for Transport (BMV), acting through the Federal Highway and Transport Research Institute (BASt).

01.11.2025 – 31.01.2027