A fatigue crack growth algorithm for mul-
tiaxial variable loading was proposed.
Crack growth models Paris’ law, Forman
eq. and NASGRO was evaluated relatively
to each other. For the tested case studies
Paris’ law was preferred.
Test and validation of numerically deter-
mined K I magnitdues. In both 2D and 3D
the accuracy was within 2% of analytical
solutions.
In a case study of a plane problem, the
crack propagation criterion of Richard was
proven to be equal, to the maximum tan-
gential stress criterion.
Numerical mixed mode I+II crack direc-
tion, showed fluactuating results, whereas
the numerical mixed mode I+III showed
good results.
Finally, a case study of mode I+III crack
growth, led to too conservative results.
The deviations noticed in the crack direc-
tion case studies, may haven been caused
by inaccurate K II magnitudes.
The fatigue crack growth deviations were
expected to show too conservative crack
growth rates, because plasticity induced
crack closure was not implemented.