Premium
Requirements for stress gradient‐based fatigue assessment of notched structures according to theory of critical distance
Author(s) -
Braun Moritz,
Müller André Mischa,
Milaković AleksandarSaša,
Fricke Wolfgang,
Ehlers Sören
Publication year - 2020
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1111/ffe.13232
Subject(s) - critical distance , structural engineering , finite element method , stress (linguistics) , fatigue limit , materials science , welding , stress concentration , sensitivity (control systems) , vibration fatigue , point (geometry) , fatigue testing , mathematics , geometry , engineering , composite material , physics , acoustics , linguistics , philosophy , sound power , electronic engineering , sound (geography)
Abstract Notches, local stress raisers within structural components, are one of the most important locations for fatigue crack initiation. It is well known that fatigue is governed by the effective stresses in the vicinity of notches. Within this study, differences in prediction accuracy between different types of theory of critical distance methods, that is, point and line methods, are systematically investigated in conjunction with a sensitivity study regarding mesh refinement, assumed strength hypothesis and material behaviour. For this purpose, a finite element analysis parameter study on notched structures is performed and recommendations for the application of stress gradient methods are presented. Difference in effective stress of up to 30%, and hence a significant difference in fatigue life (e.g., 185% for a slope of S‐N curve of k = 4), is found for typical notch shapes, for example, in welded joints.