Multiscale fatigue modelling for riveted railway bridges: A case study for real damage validation

Fatigue is a concerning process of structural degradation that impacts the maintenance in service of existing railway bridges. Analysing the corresponding damage is challenging in large structures, due to the scale difference between the full size of bridges and the millimetric or smaller areas affected by fatigue. In order to understand all the local properties that influence fatigue in riveted details, a parametric analysis is conducted using a representative case study, advising admissible values with appropriate literature review. The influence of modelling hypotheses is also investigated. These analyses contribute to guiding further studies, filling a gap in the state of the art. From the results obtained, a three-scale modelling concept is proposed, integrating an innovative modelling approach for rivets that bridges the global and local scales, focusing on the intermediate member scale, which has received less attention in past research. Such global-tolocal modelling process is applied to a real riveted railway bridge, with numerical results being confronted with actual damage data, allowing for a validation process that is scarce in the literature.