Fatigue crack growth model including load sequence effects – Model development and calibration for railway axle steels

•Fatigue crack growth model including the load sequence effects has been developed.•Plasticity- and oxide-induced load sequence effects have been derived and calibrated.•Statistical bounds have been obtained for probabilistic crack growth assessment. Beside well-known influence factors like residual...

Full description

Saved in:
Bibliographic Details
Published in:International journal of fatigue 2020-03, Vol.132, p.105377, Article 105377
Main Authors: Maierhofer, J., Gänser, H.-P., Simunek, D., Leitner, M., Pippan, R., Luke, M.
Format: Article
Language:English
Subjects:
Crack closure
Crack geometry
Crack propagation
Cyclic crack resistance curve
Fatigue crack growth
Fatigue failure
Fracture mechanics
Growth models
Load
Load sequence effects
Materials fatigue
NASGRO equation
Residual stress
Shafts (machine elements)
Short cracks
Software
Software development tools
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•Fatigue crack growth model including the load sequence effects has been developed.•Plasticity- and oxide-induced load sequence effects have been derived and calibrated.•Statistical bounds have been obtained for probabilistic crack growth assessment. Beside well-known influence factors like residual stresses, component and crack geometry also load sequence effects significantly impact the crack propagation rate. In this paper two major load sequence effects, namely overloads and small loads, and their particular influence on the fatigue crack growth are investigated in detail. Both effects lead to a retardation in the crack propagation rate by increasing the plasticity-induced (overload) or the oxide-induced (small loads) crack closure. To develop a holistic fatigue crack growth model including the short crack behaviour as well as load sequence effects, the NASGRO equation is modified accordingly. This improved fatigue crack growth approach is calibrated for two common material grades for railway axles, namely EA4T and EA1N, and implemented into crack growth assessment software tools.
ISSN:0142-1123
1879-3452
DOI:10.1016/j.ijfatigue.2019.105377