TU Darmstadt / ULB / TUbiblio

Stress gradient influence on fatigue crack growth under multiaxial non-proportional loading

Hertel, Olaf and Vormwald, Michael (2007):
Stress gradient influence on fatigue crack growth under multiaxial non-proportional loading.
In: 8th International Conference on Multiaxial Fatigue and Fracture , Sheffield, [Conference or Workshop Item]

Abstract

Commonly, basic experimental fatigue data are derived from unnotched smooth specimens. When this data is transferred to notched components, size effects have to be considered. In the present paper a fatigue life prediction approach for multiaxial non-proportional loading accounting for the geometrical size effect is presented. The approach is based on a short crack model for multiaxial non-proportional loading. The short crack model is extended by geometry correction functions for semi-elliptical surface cracks in inhomogeneous gradient stress fields. The comparison of calculated and experimentally observed fatigue lives of shouldered shafts made of S460N with notch radii of 0.2 to 4.0 mm under non-proportional tension and torsion loading yields a satisfying accuracy. The geometrical size effect is becoming significant for notch radii smaller than four times the defined technical crack size. Additionally, it is superposed by the statistical size effect. That is also taken into consideration by variation of the initial defect/crack size.

Item Type: Conference or Workshop Item
Erschienen: 2007
Creators: Hertel, Olaf and Vormwald, Michael
Title: Stress gradient influence on fatigue crack growth under multiaxial non-proportional loading
Language: English
Abstract:

Commonly, basic experimental fatigue data are derived from unnotched smooth specimens. When this data is transferred to notched components, size effects have to be considered. In the present paper a fatigue life prediction approach for multiaxial non-proportional loading accounting for the geometrical size effect is presented. The approach is based on a short crack model for multiaxial non-proportional loading. The short crack model is extended by geometry correction functions for semi-elliptical surface cracks in inhomogeneous gradient stress fields. The comparison of calculated and experimentally observed fatigue lives of shouldered shafts made of S460N with notch radii of 0.2 to 4.0 mm under non-proportional tension and torsion loading yields a satisfying accuracy. The geometrical size effect is becoming significant for notch radii smaller than four times the defined technical crack size. Additionally, it is superposed by the statistical size effect. That is also taken into consideration by variation of the initial defect/crack size.

Title of Book: 8th International Conference on Multiaxial Fatigue and Fracture
Divisions: 13 Department of Civil and Environmental Engineering Sciences > Institute of Steel Constructions and Material Mechanics > Fachgebiet Werkstoffmechanik
13 Department of Civil and Environmental Engineering Sciences > Institute of Steel Constructions and Material Mechanics
13 Department of Civil and Environmental Engineering Sciences
Event Location: Sheffield
Date Deposited: 02 Feb 2015 12:21
Export:

Optionen (nur für Redakteure)

View Item View Item