A generalized criterion for fatigue crack growth in additively manufactured materials – Build orientation and geometry effects

The effect of material anisotropy on the fatigue crack growth (FCG) behavior in additively manufactured materials is investigated by developing an energy-based criterion. The criterion is developed based on the strain energy density concept in an anisotropic domain and considers the effects of specimen geometry by introducing the T-stress in the solution. The proposed criterion is examined by predicting the FCG experimental results available in the literature for 3D-printed Inconel 718 and 17-4PH stainless steel components built in different orientations. It is found that both material anisotropies resulting from build orientation and the T-stress play remarkable roles in FCG behavior of 3D-printed components.