Tensile specimen design for LB-PBF Inconel truss-based lattice structures: Manufacturing and experimental validation

The aerospace industry strives for an optimum between sustainability, cost and resource efficiency. In this regard, additive manufacturing (AM) has established itself as a disruptive technology by offering complex part design, geometrical flexibility and hence a high degree of lightweight grade. An improved competitiveness advantage for AM in an aerospace context, can be achieved using cellular structures such as honeycombs or lattices. However, in engineering practice, lattice structures are still not yet implemented for load-bearing structures. In order to use their lightweight potential and exploit lattice potential, a reliable and reproducible assessment of the mechanical properties of lattice structures for different loading scenarios is essential. On the one hand, test specimens used for material characterization have to be designed so that the required mechanical properties are not falsified by the test specimen geometry or the experiment itself. On the other hand, the small-scale manufacturing of lattice structures and their implementation into bulk parts pose challenges. Any deviation from the initial lattice design geometry may impact the mechanical performance. It is therefore of utmost importance to establish reliable and robust method for design and manufacturing and quality assessment.