The current research presents a finite element formulation to analyze crack initiation and propagation processes in polylactic acid (PLA) components fabricated using fused deposition modeling (FDM). A phase-field-based approach, implemented in Abaqus via UELMAT user-defined subroutine, is adopted to simulate crack propagation processes. A diffusive crack model is adopted to incorporate elastoplastic behavior and to analyze fractures of manufactured polymeric components. To analyze process-induced effects of vibration-assisted FDM printing, an asymmetrically notched PLA specimens were fabricated with and without vibration assistance. Microscopic analysis of specimens reveals that vibration-assisted printing reduces porosity with a decrease in characteristic pore size from 170 microns to 70 microns, thereby increasing interlayer bonding. Comparison of experimentally measured and numerically simulated results of crack propagation paths at different notch distances reveals that numerical results using a phase-field-based approach with a user-defined subroutine are reliable and accurate. The proposed framework enables rapid design optimization and risk assessment for assemblies and prototypes manufactured locally within Hail City's growing manufacturing and similar industry ecosystem worldwide.
Said et al. (Wed,) studied this question.