Fracture mechanical characterization of the initiation and growth of interior fatigue cracks

The formation and growth of interior fatigue cracks have been studied thoroughly during the last decades, due to the high practical importance of accurate predictions about the fatigue lives of structures and machine components. This is of special interest in the VHCF regime, for which the ultrasoni...

Full description

Saved in:
Bibliographic Details
Published inFatigue & fracture of engineering materials & structures Vol. 40; no. 11; pp. 1741 - 1751
Main Author Stanzl‐Tschegg, S. E.
Format Journal Article
LanguageEnglish
Published Oxford Wiley Subscription Services, Inc 01.11.2017
Subjects
(Δa/ΔN) versus ΔK curves
Chromium steel
Chromium steels
Crack initiation
Crack propagation
Cracks
crack‐growth thresholds
Fatigue cracks
Fatigue failure
Fatigue life
fatigue limits
Fatigue tests
Fracture mechanics
interior cracks
Magnesium base alloys
Mechanical analysis
Mechanical properties
S–N curves
Thresholds
Ultrasonic testing
very‐high cycle fatigue (VHCF)
Online AccessGet full text

Cover

More Information
Summary:The formation and growth of interior fatigue cracks have been studied thoroughly during the last decades, due to the high practical importance of accurate predictions about the fatigue lives of structures and machine components. This is of special interest in the VHCF regime, for which the ultrasonic fatigue method is especially useful. Fracture mechanical values and lifetimes can be measured at constant and variable amplitudes. Endurance limits and ΔK thresholds can also be determined very quickly (e.g. 1010 cycles within a few days). Three different materials were studied. For chromium steel, internal crack formation and a fracture mechanical analysis of its growth were carried out. For a specially manufactured Mg alloy, microstructural features leading to interior cracks were analysed. Finally, for polycrystalline high‐purity copper, the conditions for interior‐crack formation and growth were determined. The utilization of FE‐SEM microscopy assisted in interpreting the prevailing mechanisms responsible for endurance limits, lifetimes and fatigue‐crack growth thresholds.
ISSN:8756-758X
1460-2695
DOI:10.1111/ffe.12622