P 1209 – Fatigue failure of runway beams due to wheel loads in heavy smeltery cranes
The replacement of German codes DIN 18800 and DIN 4132 by introduction of the Eurocodes due to the European harmonization in the technical approved area for steel construction led to a significantly more conservative classification regarding fatigue failure category details, especially for flange to web connections of runway beams in heavy smeltery cranes compared to former design experiences.
These changes would lead to a doubling of the cross-sectional thicknesses, which e.g. also can result in web plates with thicknesses of 80 mm. Execution as well as monitoring of such flange to web connections using full penetration tee-butt welds are quite critical and could no longer be realized economically.
On this account new fatigue strength classes for the runway beam specific fatigue detail “Top flange to web junction of runway beams” in EC3-1-9 table 8.10 will be derived as recommendations for an eventually modification or even extension of the current codes. Inparticular the detail executed using full penetration tee-butt welds will be investigated in the framework of this research project.
The essential core of the methodical approach is that already existing crane runway girder from practice will be examined, documented and evaluated (best prac-tice experiences) regarding the fatigue failure of the flange to web connection. In this way, a direct quantitative assessment of safety against fatigue failure for the investigated detail can be derived.
In addition, synthetic notch cases will be carried out by numerical comparative calculations as well as by including already existing results, which would not be sufficient by themselves however.
Finally, a concept will be presented for the successful and contemporary implementation of the results obtained within this research project in the current standards.
The research project was carried out at Institut für Stahlbau der RWTH Aachen University. FOSTA has accompanied the research work and has organized the project funding from the Foundation of Steel Application Research, Essen.
Only available in german language.