Experimental Investigation of Tensile and Buckling Behavior of FDM-Fabricated ABS and PLA Lattice Structures with Varying Unit Cell Geometries

Lattice structures produced via additive manufacturing (AM) have attracted substantial interest in aerospace, biomedical and automotive industries due to their superior strength-to-weight ratio and energy absorption ability. However, these cellular structures are inherently prone to buckling under compressive loading because of their open-cell geometries and slender struts. Buckling not only initiates premature structural failure but also severely limits the load-bearing capability and reliability of such structures in critical applications. While previous research has extensively explored tensile and compressive behavior, systematic and comparative investigation into the buckling performance of polymer based AM lattices remains scarce. This study addresses this gap by experimentally evaluating both tensile and buckling responses of lattice structures fabricated from ABS (Acrylonitrile Butadiene Styrene) and PLA (Polylactic Acid) using Fused Deposition Modeling (FDM). Three different unit cell geometries of square, hexagonal and octagonal with two strut thicknesses (0.5 mm and 1.0 mm) were investigated to understand the combined effects of lattice structure, material and strut thickness. The results reveal that both tensile strength and buckling resistance are significantly influenced by strut thickness and material type. PLA demonstrated superior performance over ABS particularly in terms of critical buckling loads with the most pronounced improvements observed in hexagonal lattices due to their stretch-dominated structure. These findings underscore the critical role of buckling in determining the structural integrity of AM lattice designs and offer essential insights for optimizing geometry and material selection to enhance stability and reliability in load-bearing applications.