Defects and residual stresses Finite Element prediction of FDM 3D printed Wood/PLA biocomposite

Abstract The rising interest amongst research community in utilizing PLA-based biocomposites for Fused Deposition Modelling (FDM) is driven by the increasing demand for eco-friendly and cost-effective materials for various applications. While significant progress has been made in understanding the process-structure-property relationship, the intricate interconnections involved in this context remain only partially revealed. Current lack of knowledge poses challenges in achieving optimal quality and dimensional accuracy of FDM-manufactured specimens from biocomposites. Although numerous numerical models exist for simulating the FDM process, there is a distinct need for models tailored to the specific characteristics of biocomposites. This study presents a 3D coupled thermomechanical numerical model designed to predict dimensions, defect formation, residual stresses, and temperature in PLA/wood cubes produced by FDM, considering various process parameters and composite-like nature of wood-filled PLA filaments. The accuracy of the proposed numerical model was validated by comparing its results with experimental measurements of biocomposite cubes manufactured under the same process parameters. Encouragingly, the simulated dimensions showed a maximum relative error of 9.52% when compared to the experimental data, indicating a good agreement. The numerical model also successfully captured the defect formation in the manufactured cubes, demonstrating consistent correspondence with defects observed in the experimental specimens. Moreover, the study highlighted the influence of wooden additives on defect formation.