PSI - Issue 4

Pavel Hutař et al. / Procedia Structural Integrity 4 (2017) 42 – 47

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Author name / Structural Integrity Procedia 00 (2017) 000 – 000

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however some events during the train operation can lead to peaks of load amplitude with k = 2.9. The values of stress intensity factor caused by these peaks are depicted in Fig. 3a (bending load).

Fig. 3. Components of the stress intensity factor K I as function of the crack length a for the cases: a) residual stresses are not considered, b) residual stresses are included.

Fig. 4. Load spectrum of railway axle (histogram of loading amplitudes) - Pokorný et al. (2016).

The total load (maximal load) in load cycle, K max , is given by superposition of bending ( K B ), press-fit ( K PF ) and residual stress field ( K RS ) contributions: max ( ) . ( ) ( ) ( ) B PF RS K a k K a K a K a    . (1) The minimum SIF in load cycle is given by relationship: min ( ) ( ) ( ) ( ) B PF RS K a kK a K a K a     . (2)