Fatigue crack closure under triaxial stress constraint—II. Analytical model

An analytical model for fatigue crack closure under triaxial stress constraint is established based on a modified Dugdale model as well as the asymptotic solution of three dimensional cracks. The influence of mechanical parameters, geometries of specimens and properties of materials is critically analysed. Comparing with three dimensional finite element results shows that the error of the present model is less than 3.5% for a wide range of thickness (2–30 mm). An engineering conception for the sensitive zone of stress constraint for fatigue crack closure is proposed. By use of the model, fatigue crack propagation in materials where the striation mechanism is dominant can be explained very well.