Fatigue Verification Concept for Details containing Weld Imperfections

Abstract

AbstractSteel structures subjected to repeated stress variations must be verified against fatigue in accordance with EN 1993‐1‐9 on the basis of a detail catalog. As one major concern, the background of the detail classification in terms of an extensive database does not provide information on the considered quality of welds. Certain weld imperfections are present in every construction. However, the extent of imperfection sizes that can be tolerated to provide sufficient fatigue resistance has not yet been scientifically determined.On an experimental and numerical basis, the presented concept allows the quantitative connection of fatigue classes with sizes of weld imperfections. For the two representative details of the load‐carrying‐cruciform joint and the non‐load‐carrying transverse stiffener, basic fatigue classes without explicit imperfections are calculated first. Furthermore, stress increase factors were determined that indicate the decrease in fatigue strength for weld imperfections of different type and size.A combination model is used to determine the fatigue strength of a detail with multiple weld imperfections. Using a simple formula and reading fatigue classes and reduction factors in tables, the fatigue strength of an imperfect detail can be easily determined.