PSI - Issue 19

Aissa Ouballouch et al. / Procedia Structural Integrity 19 (2019) 433–441 Aissa Ouballouch et al./ Structural Integrity Procedia 00 (2019) 000 – 000

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3. Results & discussion The 3D Volumic equipment was used to fabricate GRPA and KRPA samples for tensile testing, dimensional accuracy and total cost assessment. The mechanical performance and above-mentioned evaluations of these samples are discussed in this section. 3.1. Dimensional accuracy and repeatability The measurements of specimen dimensions were averaged into a single value for each dimension in each sample. By comparing these measured and averaged values with the design dimensions, the figures below were created using error Equation 2. Error = Measured Value – Design value (2) The following figures and lines discuss the influence of investigated processing parameters on the dimensional accuracy of studied reinforced PA (RPA) specimens. -Effect of print speed: Looking at Figure 5, the impact of print speed on dimensional error of KRPA and GRPA parts is slight. However, there is an exception for length error of GRPA that is significantly affected. The width and reduced width errors represent the highest values while the thickness error is the lowest. Also from this Figure, it can be seen that the errors in all measured dimensions are lower in the case of GRPA material except the length error. This latter has the positive values for both materials.

0 0 0 , , , 1 2 3 0 0 0 , , , 4 5 6 0 0 , , 7 8

50 55 60 65 70 - - - 0 0 0 , , , 8 7 6 - - - 0 0 0 , , , 5 4 3 - - 0 0 0 , , , 2 1 0 Length error KRPA Reduced width error KRPA Length error GRPA Reduced width error GRPA Width error KRPA Thickness error KRPA Width error GRPA Thickness error GRPA Print Speed [mm/s]

Dimensional error [mm]

-Effect of extrusion temperature: Figure 6 shows the evolution of dimensional errors with the variation of extrusion temperature. The first observation is that the lower error of different dimensions is achieved at temperature 245°C. From 255°C and 265 °C, the errors are slightly affected by the extrusion temperature. From Figure 6, length error is significantly affected by the temperature while other dimensions’ errors are less depending on the temperature. Overall, the most of the errors have positive values. In other words, the length reduced as the temperature rises. For other dimensions, they tend to be higher than their values in 3D model. Fig. 5. Dimensional error of RPA as function of print speed