Thermal Modeling of Fused Deposition Modeling Process Using Discrete Elements

Over the years various models have been proposed to predict the material behavior during fused deposition modeling (FDM) process. FDM produced components show anisotropic material properties as compared to the virgin materials produced via injection molding. The thermal phenomena subjected to the filament during the FDM process leads to temperature gradient between filaments within a layer and across layers. This affects the adhesion and bond formation between the filaments and leads to directional differences in bonding strengths throughout the component. In this study, discrete elements have been used to study the thermal cooling behavior of FDM deposited filaments. This approach is a discontinuous methodology which follows the idea of dividing the filaments into discrete elements with simplified geometry for calculating the thermal interactions between the elements. The model uses the lumped capacitance model along with a set of heat transfer boundary conditions that considered the contact between the element and the surroundings, between the element and the build plate, and between elements. The model was applied to different testcases of various sizes and different printing conditions. The behavior of the model was found to be consistent with previous alternative models and followed the observed behaviors in FDM printing