A Comparative Numerical Investigation on Machining of Laminated and 3D Printed CFRP Composites

One of the shortcomings of 3D printed or laminated carbon fiber reinforced polymer (CFRP) composites is that their dimensional precision and surface finish fall short of the normal tolerance requirements for most industrial applications. Machining is often necessary as a post-processing step to get the CFRP parts in appropriate form. This research uses numerical modeling and simulation with ABAQUS/Explicit, a commercially available sophisticated finite element analysis (FEA) software program, to compare the machining behavior and post-processing capabilities of laminated and 3D printed CFRP composites. The effects of machining parameters, such as, feed, cutting speed and depth of cut (DOC), and 3D printing parameters like percentage of overlap between neighboring passes and layer heights, have been investigated. Cutting forces, strain, chip and burr development, and the consequent surface topology have all been used to assess the post-processing capability or machining behavior of CFRPs. A 3D model was built using appropriate damage initiation and propagations factors such as ductile and shear damage, as well as the Johnson-Cook criteria for plasticity. C3D8R elements, which are 8-node brick elements, were used to mesh each layer of the laminated workpiece model. For 3D printed models, linear tetrahedral elements, also known as C3D4T, were employed to capture changes in elemental level. The cutting and thrust forces generated increased as the DOC, cutting speed and feed rate increased. Chip formation was primarily controlled by stiffness and flute shape of the cutting tool, and 3D print direction. It was seen that the surface quality is better for laminated CFRPs. The highest cutting force obtained are found to have an essentially proportional correlation with feed, layer height, and spindle speed. Finally, the findings are persuasive, and they may be utilized to direct actual machining operations and achieve the required results.