Analysis of fatigue strength for AM lattice components using FCM based on strain energy density approach
Please login to view abstract download link
Fatigue properties are an essential aspect of metallic additively manufactured (AM) lattice components that has been the subject of many studies. Proper characterization of fatigue strength for such components call for computational methods that consider the impact of manufacturing-induced internal pores and surface defects in adequate resolution. This work investigates the fatigue properties of two LPBF Ti6Al4V lattice components using: (a) Image-based finite cell method (FCM) to consider the effect of the geometrical defects based on CT images (b) Strain energy density (SED) approach to characterize the fatigue failure based on the critical SED value. The image-based FCM has been effectively employed to resolve fine geometric details of various as-built AM components, and preliminary work on fatigue life prediction with such an approach was shown to be promising. On the other hand, SED-based approaches have been successfully applied to analyze the fatigue life of various metallic components. In this work, we compare the critical SED value from physical experiments to the computationally estimated critical SED value based on the volume-based SED criterion. We conclude that the computed critical SED values match closely with the experimental fatigue results, and the proposed workflow can be used to assess the fatigue life of metallic AM lattice components with fine geometric features.
