Effect of microstructural morphology on mechanical response of 3D-printed short-fiber-reinforced ABS composites

Mechanical properties of additively manufactured short-fiber-reinforced polymer composites depend on both the process parameters and the microstructural morphology of composites. Typically, reinforced thermoplastic polymer filaments are produced without control of the distribution of fibers, which may result in underestimation of the mechanical performance of 3D-printed parts. This study numerically investigates the impact of changes in microstructural parameters on the effective mechanical properties of acrylonitrile-butadiene-styrene (ABS) reinforced with carbon, glass, and basalt short fibers, using computational tools of mathematical morphology and finite-element (FE) modeling. The data on the internal arrangement of short fibers in the polymer are obtained with micro-computed tomography of the filament samples and presented as statistical distributions of fiber lengths and orientation angles. Three-dimensional representative volume elements are created in FE software with both original and modified distributions of the morphological parameters of reinforcement. The elastic properties of composites are assessed for cases when parameters of short-fiber distribution deviate from their original values. The results indicate that control of the microstructural arrangement of short fibers during filament manufacturing can increase the elastic modulus of reinforced ABS.