Influence of layer thickness on the tensile and low-velocity impact behavior of FDM-printed PLA–CF composites: A combined numerical and experimental study

Abstract

Predicting the mechanical behavior of fused deposition modeling (FDM) carbon fiber-reinforced thermoplastics remains challenging due to their process-induced heterogeneity and anisotropy. This study investigates the influence of layer thickness on the tensile and low-velocity impact behavior of FDM-printed PLA–carbon fiber (PLA–CF) composites using a combined experimental and numerical approach. Specimens with 0.1 and 0.2 mm layer thicknesses were manufactured while keeping the other printing parameters constant. A three-dimensional finite element model was developed in Abaqus using an equivalent homogeneous isotropic elastoplastic formulation and calibrated from the experimental tensile response. The model was validated against the experimental stress–strain behavior and subsequently extended to simulate low-velocity impact. The tensile simulations showed good agreement with the experiments, with maximum von Mises stresses of 27.08 and 28.14 MPa for 0.1 and 0.2 mm layers, respectively. Under impact loading, the 0.2 mm configuration exhibited higher peak contact force and stiffness, whereas the 0.1 mm configuration provided slightly higher energy absorption. Additional simulations demonstrated the significant effects of impactor geometry and velocity on the dynamic response. The proposed framework provides a computationally efficient approach for assessing FDM-printed PLA–CF composites.