Fatigue behavior of girder with flange thickness transitions and cope holes - test and simulations

The fatigue behavior of steel girders with flange thickness transition and cope hole has been experimentally analyzed with two large-scale cyclic tests. Special attention is paid to the arising and interacting local effects. The fatigue tests have been conducted in a four-point bending setup. Both girders have shown fatigue-induced failure at the flange butt welds at the thickness transition. The experimental results are presented in terms of fatigue life, differentiating the initiation and propagation life, as well as observed crack position and shape. Moreover, an advanced fatigue life prediction using the Two-Stage-Model is applied to the tested girders. The Two-Stage-Model applies the Strain-Life and the Crack Propagation Approach to assess the total fatigue life. Thereby, the number of cycles as well as the crack shape show a good agreement with the experimental results and proves the applicability of the Two-Stage Model for an advanced fatigue assessment