Process Modeling of Additively Manufactured Semi-Crystalline Thermoplastics

Additively manufactured parts often exhibit process-induced geometrical distortions and residual stresses due to the thermal history imposed by the printing process. These effects can be further amplified by shrinkage strains that develop due to the semi-crystalline nature of the thermoplastic material. The present work extends previous efforts in the development of a process model for additive manufacturing by incorporating the capability to predict distortions based on the part’s thermal profile during the printing process. The numerical framework is based on higher-order finite elements derived from the Carrera Unified Formulation. The element activation approach is employed to simulate the additive manufacturing process, while a non-isothermal crystallization kinetics model determines the material state as a function of the processing conditions. Representative numerical assessments are performed to demonstrate the capability of the proposed process modeling framework.