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Process Modeling of Thermosetting Polymers Manufactured Using Fused Deposition Modeling



Achieving dimensional control for fused deposition modeling (FDM) of polymeric parts can be tedious and often involves inefficient trial-and-error experimentation through adjusting print parameters. These inefficiencies may be reduced through the use of process modeling. Understanding the fundamental effects of the print conditions will facilitate predicting part dimensions as well as strength, accounting for the degree of contact between roads, thermal history, and residual stresses. Modeling of additive processes is complex due to transient local boundary conditions and a continually increasing part volume throughout the printing process. Numerous previous studies in FDM have focused on varying experimental process variables such as print speed, extrusion, build temperatures, and print path to determine their effect on mechanical properties. Fewer efforts, however, investigate the complex thermo-mechanical history throughout the printing process or the driving mechanism in road-to-road bonding due to local re-melting of previously solidified material and diffusion. In this research, a 3D finite element model framework for predicting the thermal and residual stress history of an additively manufactured thermosetting polymer is presented. By incorporating material sub-models with the Abaqus FEA solver, the model is able to capture the cure kinetics during the printing process. The model takes a high-fidelity approach through the modeling and stepwise activation of individual roads to simulate the deposition process. Further, the geometry (i.e. cross-section) is varied to demonstrate a mechanism capable of including future research road-to-road bonding.

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