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An analytical fracture mechanics model for predicting the finite life fatigue strength of components is
presented which combines a number of well established and newly developed approaches such as
Murakami's and McEvily's approach for describing the transient behaviour of crack closure of short
cracks, the analytical (long) crack closure function of Newman which became part of the widely used
NASGRO approach, the R6 procedure, a method for improving the ligament yielding correction f(Lr ) of
R6 proposed by the authors of the present paper and other elements. Basic assumption is the preexistence
of initial flaws such that the crack initiation or nucleation stage is small and can be neglected.
The application of the model is demonstrated for small tension plates of aluminium Al 5380 H321 with
artificial initial defects generated by FIB technology, the size of which was fixed on the basis of
fractographic investigations on broken, smooth specimens.
Recently three of the authors of this paper presented analytical solutions for reference loads of plate geometries with semi-elliptical surface cracks subjected to tension, bending, combined tension-bending and biaxial tension. These solutions were shown to provide more accurate crack driving force estimates than the conventional limit load solutions available in the literature, and the method behind them allowed for a wider application range. Within the present paper a methodology for the fracture analysis of thick-wall pressurized pipes using the R6 assessment method and considering both, biaxial and combined tension-bending loading is developed and validated. The analyses are carried out analytically, and the comparison between the predicted critical loads and experimental burst test failure loads shows satisfying agreement, this way demonstrating the potential of the proposed method.