Strain-based method for fatigue failure analysis of truss lattice structures: modeling and experimental setup

Lattice structures, as a subclass of cellular solids, are nowadays among the most promising materials when it comes to lightweight engineering: their excellent mechanical properties, together with their functionality and reduced mass, make them the perfect candidates for many applications in the aerospace and automotive fields. Such sectors require though demanding specifications for their components: among all, fatigue resistance is extremely important. A simplified method for the fatigue analysis of lattice structures, based on finite element method (FEM) is proposed: through linear homogenization of the lattice structure, a lighter FEM model employed for the fatigue failure analysis is developed. Second step of the model is the application of de-homogenization on the most critical cell and therefore the recovery of the true state of the lattice. In this investigation, the method is employed in the case of a 4-point bending cyclic load, together with the presentation of a validating experimental setup.