Despite the great potential of additively manufactured (AM) metallic lattice materials, a comprehensive understanding of their mechanical behavior, particularly fatigue, has yet to be achieved. The role of the sub-unital lattice elements, that is, the struts and the nodes (or strut junctions), is rarely explored, even though it is well known that fatigue is a local phenomenon, determined by the small features of a structure (defects and local geometrical discontinuities). In this work, the mechanical behavior of nodes and struts has been investigated by designing laser powder bed fusion (L-PBF) Ti6Al4V single strut specimens, with a node placed in the central part of the gauge length. The specimens were manufactured according to four different building orientations, namely, 90°, 45°, 15°, and 0° to the build plane. The influence of the fillet radius at the node and of the printing direction on the fatigue strength has been examined.

Selective laser melting (SLM) process is used to produce complex geometries for various applications such as biomedical and aerospace industries. However, one of the limitations with respect to this process is the introduction of geometrical defects during the manufacturing process. The presence of these defects makes it difficult to predict their mechanical behaviour. The present work focuses on the cubic lattice structures and their geometrical deviations from the as‐designed structures, caused by defects like strut oversizing, varying thickness and strut waviness. The defects were introduced in finite element modelling by using different cross‐sections along a strut and joining them to form smooth solid struts. The modelling of defects were validated by comparing with experimental data. The results indicate an appreciable difference between as‐designed and as‐built structures. It was observed that, varying the strut thickness had a major effect on the strength of the structures. Additionally, an elliptical cross‐section better matched the tensile behaviour of the as‐built structures rather than a rectangular cross‐section.