Numerical simulations on thermomechanical performance of 3D printed chopped carbon fiber-reinforced polyamide-6 composites: Effect of infill design

3D printing (3DP) of polymer composite products and solutions mainly relies on experimental techniques for research & development and product/process/system understanding. Several studies experimentally investigated the effect of infill patterns and densities on the mechanical performance of 3D printed polymer composites. However, due to the unlimited design flexibility of 3DP processes and polymer composite recipes, it is vital to explore numerical simulation tools to speed up research and development time and reduce costs. In this study, we present the development of computational modeling for 3D printed polymer composites using a numerical simulation tool (Digimat-AM®) to predict the fused filament fabrication process-induced deflections, residual stresses, and warpage in 3D printed specimens. Digimat-AM® provides a platform to simulate the fabrication of 3D printed parts, which can assist the designers, engineers, and researchers to predict the manufacturing and resulting product issues beforehand. This study aims to understand the effect of different infill patterns and densities on deflections, residual stresses, warpage, and mechanical properties on 3D printed samples. A significant impact of infill pattern and density is observed on deflections, residual stresses, and warpages from numerical simulation results. In addition, the mechanical testing simulations were performed on the specimens with 3DP process-induced defects obtained from the process simulation results. Finally, the numerical simulation results for mechanical testing were validated and compared with physical testing on 3D printed specimens. The results found a satisfactory agreement where differences remain with an acceptable range of 0.22%–7.27%.