Notched structural steel specimens assessed by selected fatigue analysis methods

This paper focuses on fatigue estimation of notched components. It discusses two major concepts - critical distance theory and solutions based on the relative stress gradient - and specific criteria related to them. It checks their quality by validating their output on own experimental data retrieved in fully-reversed tension and in fullyreversed torsion on unnotched and notched specimens manufactured from CSN 411523 structural steel (equivalent to S355J2). The solutions based on the stress gradient provide better estimates. However, these two calculation concepts process the input data differently and use them for calibrating their parameters. Together with the limited scope of the experimental set, this has prevented the authors reaching a final verdict on ranking the estimation quality of the compared criteria. The output of our investigation shows that the solutions proposed within the concept of a relative stress gradient are currently more practical for use in the general engineering domain.