Numerical investigation on mechanical properties of cellular lattice structures fabricated by fused deposition modeling

Abstract

Cellular lattice structures (CLS) with designed structural integrity are highly demanded in many applications such as light-weight industrial components and bone scaffold. In recent years, additive manufacturing (AM) processes have been found to be capable of producing such products with controllable porosity and pore sizes. However, AM faces an inherent obstacle so that the CLS strut diameter varies along its length. This study uses finite element modeling to predict the effect of variation in the struts׳ diameter on the elastic modulus as well as collapse stress of CLS using both beam and solid finite elements. To determine the mechanical behavior of the lattice and bulk material, lattice structures as well as compression test specimens are fabricated using fused deposition modeling. The results show that the beam finite element model is stiffer than the solid one since the beam model cannot capture the effects of material concentration at the points of diameter variations. However, the obtained elastic modulus does not differ significantly between solid and beam models while the difference is not negligible for collapse stress.