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In Fused Deposition Modeling (FDM), which is a common thermoplastic Additive Manufacturing (AM) method, the polymer model material that is in the form of a flexible filament is heated above its glass transition temperature (Tg) to a semi-molten state in the head’s liquefier. The heated material is extruded in a rastering configuration onto the building platform where it rapidly cools and solidifies with the adjoining material. The heating and rapid cooling cycles of the work materials exhibited during the FDM process provoke non-uniform thermal gradients and cause stress build-up that consequently result in part distortions, dimensional inaccuracy and even possible part fabrication failure. Within the purpose of optimizing the FDM technique by eliminating the presence of such undesirable effects, real-time monitoring is essential for the evaluation and control of the final parts’ quality. The present work investigates the temperature distributions developed during the FDM building process of multilayered thin plates and on this basis a numerical study is also presented. The recordings of temperature changes were achieved by embedding temperature measuring sensors at various locations into the middle-plane of the printed structures. The experimental results, mapping the temperature variations within the samples, were compared to the corresponding ones obtained by finite element modeling, exhibiting good correlation.

Residual stresses and strains generated in additively manufactured (AM) components have significant impact on their dimensional integrity. This work aims at characterizing the residual strains and deformations in square plates fabricated using the fused deposition modeling (FDM) process. The induced residual strains at the end of the printing process were measured through the integration of fiber Bragg grating (FBG) sensors, while the exhibited out‐of‐plane deformations of the plates were obtained using the digital image correlation (DIC) technique. The experimental results demonstrate significant part distortions at the plates' corner locations but without proceeding to quantitative correlation between the FBG and the DIC measurements.

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