Influence of lattice topology and loading orientation on the anisotropic mechanical performance of additively manufactured cellular structures

Additive manufacturing facilitates the fabrication of complex cellular lattice structures with controlled porosity, enabling the development of lightweight components with enhanced mechanical performance and energy absorption capabilities. In this study, the mechanical behaviour of three unit-cell-based lattice structures, namely face-centered cubic (FCC), body-centered cubic (BCC) and a hybrid face and body centered cubic (FBC) topology, was experimentally investigated. The lattice structures were modelled with a strut diameter of 2 mm and a height-to-width ratio (H/W) of 1.0 and fabricated using fused deposition modelling (FDM) with polylactic acid (PLA). Compression tests were conducted along the X, Y and Z directions to evaluate Young’s modulus, compressive strength, total energy absorption and specific energy absorption. The results revealed a strong dependence of mechanical performance on lattice topology and loading orientation. Among the investigated configurations, the hybrid FBC lattice exhibited superior overall mechanical performance, achieving a maximum Young’s modulus of 498.71 MPa, compressive strength of 23.49 MPa, total energy absorption of 163.99 J and specific energy absorption of 18.94 kJ/kg. These results demonstrate that the hybrid FBC topology provides improved stiffness, load-bearing capacity and energy absorption compared with the FCC and BCC structures. The significance of the present study lies in demonstrating the mechanical advantage of combining face and body centered unit-cell features within a hybrid lattice architecture. The findings demonstrate the potential of hybrid cellular architectures for lightweight engineering applications requiring enhanced load-bearing and energy-absorbing performance.