Large-scale fatigue tests on thick walled circular hollow sections

The fatigue strength according to EN 1993-1-9 and other recommendations for the design of steel structures are generally determined by fatigue tests. Because of cost and time reasons fatigue tests are usually performed on small-scale specimens. However, test results gained on these specimens with smaller dimensions cannot cover the influence of a possible size-effect on the fatigue strength. For the transfer of the fatigue strength to real structures with larger dimensions and larger wall thicknesses additional large-scale fatigue tests are required. At the University of Applied Sciences Munich, several large-scale fatigue tests on thick walled circular hollow sections with welded K-joints were performed in recent years. The large-scale fatigue tests had dimensions similar real structures with lengths up to 18 m, weights up to overall 17 tons and wall thicknesses up to 60 mm. Within this paper, the used test bench for the large-scale fatigue tests is described and the results are discussed regarding the influence of the size effect. © 2021 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.