Comparative study of experimental thermographic data and finite element analysis on temperature evolution of PET-G layer deposition during additive manufacturing process

Additive manufacturing (AM) technologies gain popularity in recent years due to patent releases - and in effect - better accessibility of the technology. One of most popular AM technologies is fused deposition modeling (FDM) which is used to manufacture products out of thermoplastic polymers in a layer - by - layer manner. Due to the specificity of the method, parts manufactured this way tend to have non-isotropic properties. One of the factors influencing the part's mechanical behavior and quality is the thermoplastic material's bonding mechanism correlated with the processing temperature, as well as thermal shrinkage during processing. In this research authors verified the suitability of finite element method (FEM) analysis for determining PET-G thermal evolution during process, by creating layer transient heat transfer model, and comparing the obtained modelling results with ones registered during real-time process recorded with FLIR T1020 thermal imaging camera. Our model is a valuable resource for providing thermal conditions in existing numerical models that connect heat transfer, mesostructure, and AM product strength, especially when experimental data is lacking. Presented FE model reached maximum sample-specific error of 11.3%, while arithmetic mean percentage error for all samples and layer heights is equal to 4.3% which authors consider satisfactory. Model-to-experiment error is partially caused by glass transition of the material, which can be observed on experimental cooling rate curve after processing the temperature signal.