A numerical model based on the theory of critical distances has been developed to simulate
the fatigue crack propagation for cast aluminum alloys under mode I loading. The
accumulated plastic energy density at the critical distance point ahead of the crack tip is
used as a measure of the fatigue damage. The effect of different R-ratios on the crack
propagation rate is correctly predicted using the proposed methodology. For the 319 cast
aluminum alloys investigated in the present paper, the critical distance is of the same order …

A numerical model of fatigue crack propagation based on the Theory of Critical Distances
has been developed in a previous paper (Zheng et al., 2013 [1]). The present study aims to
investigate the capability of the crack propagation model to predict the effects of overloads
and underloads. The plastic energy density at the critical distance ahead of crack tip is
affected by the changes in the plasticity-induced crack closure levels and has been used as
a measure of the fatigue damage. It is concluded that the predicted crack retardation and …