Abstract
Against the background of the unsatisfactory situation regarding the economic efficiency of fatigue-stressed steel structures and the real chances of a more efficient design, the superior objective of research projekt is the systematic re-evaluation of essential parameters of fatigue strength according to EC3-1-9 with regard to construction details of steel and composite bridge, crane and crane runway construction as well as mast and chimney construction. For this purpose, the existing DASt database is to be expanded and extended to include previously outstanding tests on essential details. Furthermore, additional experiments on influencing variables that could not be evaluated so far have to be carried out. This concerns in particular experimental investigations on the geometric influence as well as the manufacturing and tolerance influence on the fatigue strength of welded connections.
Expansion of the existing DASt-Database:
The first step to achieve the main objective of the present proposal is the further development of the DASt experimental database. On the one hand, additional experimental databases such as the experimental database of the German Railway (Deutsche Bahn) are to be made accessible and added to the database. On the other hand, the results of the additional own experiments of the project partners and further current experimental data from the literature are to be added, if available.
Optimization and simplification of the notch case classes:
For important basic notch cases such as butt welds or welded-on longitudinal stiffeners, the actual size influence must be specified in order to optimize and simplify the definition of notch case classes. It must be examined how these considerations can be transferred to other comparable notch types.
Connection of notch classes with limit values of manufacturing tolerances:
For a more economical fatigue design, the influence of weld seam irregularities is to be quantified for selected notch cases such as cross joints or transversely stiffened beams, so that an allocation to different notch case classes is made depending on the usual or newly defined evaluation classes. The aim is to specify permissible limit values of imperfections in order to meet the minimum requirements of the notch classes.
Improved notch classes due to consideration of high production quality:
In addition, a consideration of high manufacturing quality shall be achieved by the possibility of classification in improved notch classes depending on the manufacturing influence or the weld seam quality. The aim is the appropriate normative implementation for practice, in which, on the basis of the new regulations in the design standard EC 3-1-9, proposals are also made for a corresponding adaptation of the design rules in DIN EN 1090-2. This is because significant progress in terms of resource and cost-efficient design and execution can only be achieved if design and execution is regulated and organized “hand in hand”.
Project Team
RWTH Aachen, Institute of Steel Construction and Chair of Steel and Lightweight Metal Construction, Prof. Dr.-Ing. Markus Feldmann, Helene Bartsch, M.Sc.
Karlsruhe Institute of Technology, Research Center for Steel, Timber and Masonry
University of Stuttgart, Institute of Structural Design,
Prof. Dr.-Ing. Ulrike Kuhlmann, Gloria M.K. Hofmann, M.Sc.
Project Funding
Anwikar Consultans
Bde GmbH – Consultation
DB Netz AG – Consultation
Dillinger Hüttenwerk – Donation of the sample material
Donges SteelTec GmbH
Ingenieurbüro Dr. Schleicher – Consultation
Klähne Beratende Ingenieure
Max Bögl Bauservice
Meyer + Schubart Partnerschaft beratender Ingenieure – Consultation
OWT GmbH (Offshore Wind Technologie)
Schachtbau Nordhausen Stahlbau GmbH – Consultation
Siemens Gamesa Renewable energy – Consultation
Project Term
October 1st, 2020 – September 30th, 2023