Large Format Additive Manufacturing: G-Code-Driven Process Simulation, Material Characterization and Experimental Warpage Validation

Large Format Additive Manufacturing (LFAM) is becoming a promising technology to manufacture composite structures. It offers greater freedom to generate complex mold geometries, while providing reduced cost and lead times. This study is focused on characterizing the Fused Granular Fabrication (FGF) additive manufacturing process of Acrylonitrile Butadiene Styrene (ABS) reinforced with 20% short glass fiber, as this material’s properties allow it to be extensively used in low-temperature tooling applications. The main goal is to generate a finite element method (FEM) that can compute and predict the warpage of the produced tooling by creating a multi-physics simulation workflow that uses the printing path “.gcode” file as an input. With ANSYS’ feature of element activation, it is possible to model the layer deposition and assess the process-induced deformations. While the simulated thermal field was validated against in situ infrared thermography, the warpage results were compared with experimentally measured deformations of three probes, in order to evaluate the consistency between the numerical results and physical responses. Therefore, it was also initially required to assess the thermal and mechanical properties of the glass fiber-reinforced ABS after extrusion, including coefficient of thermal expansion measurements and tensile tests. The results reveal high material anisotropy, mainly generated by the manufacturing process, as the reinforcing short glass fibers tend to align with the printing direction. This approach and the data it provides can be used to guide the 3D printing operation, as it helps to identify potential tooling tolerances included during the part design and achieve first-time-right manufacturing of the composite molds.