Issue 50

N. Chatzidai et alii, Frattura ed Integrità Strutturale, 50 (2019) 407-413; DOI: 10.3221/IGF-ESIS.50.34 412 (a) (b) Figure 5 : Temperature profiles as recorded by thermocouples integrated in 21 st layer together with the temperature peak values for: (a) 0° and (b) 90° raster orientation. 5), ensures greater bonding of the rasters within the fabricated specimen, and thus, approaching the ideal theoretical solid model that was used to perform the simulations. On the other hand, the differences between the experimental and the simu- lated temperature profiles of Figs.3(a,b) (max 5°C), show that the gaps between the rasters should be taken into account. C ONCLUSIONS n the present work 3D printed rectangular polymer specimens were fabricated under different building speeds and orientations. Temperature sensors were integrated throughout the center of the 1 st and/or 21 st building layer of these specimens to investigate the temperature profiles generated during the fabrication process. The experimentally obtained results were compared to the corresponding ones derived by the thermal diffusion finite element analysis. The experimental results demonstrate an undulated temperature profile with a declining pattern. Higher rates of the printing nozzle in conjunction with shorter printing path lead to the preservation of higher temperature values inside the specimen. The thermal behavior of the specimen is influenced both by the extruded material and the heated printing platform even during the end at the printing process. The simulation based calculated maximum temperature values exhibit good agreement, in general, with the experimentally measured ones, presenting a maximum difference of 5°C. However, by increasing the printing speed and decreasing the printing tool-path the rasters’ bonding enhances leading to a more solid 3D printed specimen which approaches the ideal model considered in the FEM analysis. R EFERENCES [1] Chua, C.K., Leong, K.F., Lim, C.S. (2010). Rapid Prototyping, Principles and Applications, World Scientific. [2] Coogan, T.J., Kazmer, D.O. (2017). Bond and part strength in fused deposition modeling, Rapid Prototyp. J., 23(2), pp. 248–257, DOI: 10.1108/RPJ-03-2016-0050. [3] Ahn, S., Montero, M., Odell, D., Roundy, S., Wright, P.K. (2002). Anisotropic material properties of fused deposition modeling ABS, Rapid Prototyp. J., 8(4), pp. 248–257, DOI: 10.1108/13552540210441166. [4] Bellini, A., Güçeri, S. (2003). Mechanical characterization of parts fabricated using fused deposition modeling, Rapid Prototyp. J., 9(4), pp. 252–264, DOI: 10.1108/13552540310489631. [5] Bellehumeur, C., Li, L., Sun, Q., Gu, P. (2004). Modeling of bond formation between polymer filaments in the fused deposition modeling process, J. Manuf. Process., 6(2), pp. 170-78, DOI: 10.1016/S1526-6125(04)70071-7. [6] Shofner, M.L., Lozano, K., Rodríguez-Macías, F.J., Barrera, E. V. (2003). Nanofiber-reinforced polymers prepared by fused deposition modeling, J. Appl. Polym. Sci., 89(11), pp. 3081–3090, DOI: 10.1002/app.12496. [7] Es-Said, O.S., Foyos, J., Noorani, R., Mendelson, M., Marloth, R., Pregger, B.A. (2000). Effect of Layer Orientation on Mechanical Properties of Rapid Prototyped Samples, Mater. Manuf. Process., 15(1), pp. 107–122, DOI: 10.1080/10426910008912976. I