Triaxial Compression of Anisotropic Voronoi-Based Cellular Structures

This study examines the effect of geometrically controlled anisotropy on the compressive behaviour of additively manufactured Voronoi cellular structures. Three configurations—an isotropic reference and two anisotropic variants generated by scaling the design domain along the Z-axis—were fabricated by stereolithography using a tough photopolymer resin. All specimens exhibited an approximate nominal porosity of 80%. Compressive tests were conducted along the X, Y, and Z directions in accordance with ASTM D1621. The elongated structure showed enhanced stiffness and strength when loaded parallel to the scaling axis, whereas the compressed structure exhibited improved performance in the transverse directions. The isotropic structure displayed similar responses in all axes. These results demonstrate that geometric scaling effectively induces directional mechanical anisotropy without altering relative density, offering a simple route to tailor the load-bearing behaviour of lightweight architected materials.