Multiscale homogenization-based finite-element modeling of fused filament fabrication (FFF)-printed polylactic acid (PLA) components for mechanical performance prediction

This study investigates the mechanical behavior of polylactic acid (PLA) components manufactured by fused filament fabrication (FFF) through a combined experimental and homogenization-based numerical approach. The effects of raster orientation (0°, 45°, and 90°) and strain rate (10 ⁻⁴ –10 ⁻² s ⁻¹ ) on tensile properties were evaluated. Representative volume elements (RVEs) were used to determine the effective orthotropic elastic properties of the printed material, which were subsequently implemented in macroscale finite-element simulations. Experimental validation was performed using ISO 527-2 Type 1BA tensile specimens. The results showed that raster orientation and strain rate significantly influence the mechanical response of FFF-printed PLA. The 90° raster configuration exhibited the highest stiffness and strength, whereas the 0° configuration showed lower performance due to its greater dependence on interlayer bonding. The numerical model successfully reproduced the overall mechanical trends and anisotropic behavior of the printed structures, although discrepancies remained for Young's modulus and ultimate elongation because of the assumptions of perfect interlayer bonding and the absence of viscoelastic and damage mechanisms. The proposed framework provides an efficient tool for predicting the mechanical behavior of FFF-manufactured components while reducing experimental effort and supporting process optimization in additive manufacturing.