A comparative study of the fatigue behavior of Ti‐6Al‐4V circular lattices using numerical and experimental methods

Abstract

AbstractLattice materials are a subset of cellular solids with a periodic microstructure and are of interest in a number of applications because of their potential weight‐saving properties. In this study, circular lattices are machined out of plates made of Ti‐6Al‐4V and fatigue tested to generate an S–N curve. These results are compared to a FEM with fatigue data based on MIL‐HDBK‐5H. A good agreement with the FEM was found, suggesting that the fatigue life of lattices can be modeled without specifically detailed fatigue data. The model accurately predicted the point of failure in most of the lattice specimens and was within 4% of the scatter band. Fractographic analysis showed significant shear features in the fracture surfaces, indicating a rapid shear fracture is likely the dominant mode of failure. Finally, the relationship between equivalent stress and relative density was determined using a variety of optimization schemes.