Prediction of anisotropic LCF behavior for SLM Ti-6Al-4V considering the spatial orientation of defects

•A principal component analysis based ellipsoidal equivalence criterion for AM material defects is developed.•Polar figures are used to correlate the size and spatial orientation of equivalent defects with the building direction.•Orientation texture of defects and differences in stress-strain relationships leads to the anisotropic fatigue resistance of AM materials in different building direction.•Lifetime for different building direction specimens is well predicted by the LCF lifetime method developed considering the orientation texture of defects.