This paper deals with life prediction by observation and simulation of short fatigue cracks in cyclically loaded smooth and notched specimens made of 0.15 wt-% carbon steel SAE1017. The measured crack behaviour was simulated in a microstructural environment. Reference tests under constant amplitude loading allowed to determine model parameters and hence a reasonable life prediction by simulation resulted even for service loading. Short crack behaviour was a measurable property for damage also to compare smooth and notched specimens.
The development of procedures to calculate the service life of railway rails requires test results which describe the damage of rails thus affording their validation. Within the DEUFRAKO integrated project NOVUM, ten rail specimens were tested under constant and variable amplitude loads to investigate the propagation of lateral cracks and to ascertain the service life. The test conditions were based on real rail loading and were used in the 3-point-bending test frame under alternating stress. An eccentric notch was applied as pre-arranged damage in the 60 E1 (260) rail specimens. The notched rails showed a similar behaviour like rails with strong head checks damaged by rolling contact fatigue.