This research focuses on modeling the thermal expansion behavior of high-end 3D printed fiber-reinforced polymer composites during autoclave cycles. Utilizing a combination of finite element analysis (FEA), analytical modeling, and experimental thermo-mechanical testing, the study aims to predict and validate the coefficient of thermal expansion (CTE) of these materials.

The investigation primarily examines the influence of fiber orientation and void content on thermal expansion properties. Experimental techniques, including optical microscopy, x-ray tomography, and dynamic mechanical analysis (DMA), were employed to assess microstructural properties and thermal behavior. Results indicate that the use of a breaker plate during extrusion enhances random fiber orientation, promoting isotropic thermal expansion.

The CTE values for aligned and random fiber orientations were analytically modeled using short fiberreinforced polymer (SFRP) models, demonstrating good alignment with experimental data trends. The study also found that void content only minimally affects CTE, contributing to a slight increase of approximately 5%.

Despite discrepancies between FEA predictions and experimental outcomes, FEA remains a valuable tool for identifying thermal expansion trends and guiding manufacturing process optimizations. Future work should refine modeling assumptions and expand experimental validation to enhance the predictive accuracy of thermal expansion behavior in large-format 3D-printed molds.