PSI - Issue 41

N.A. Fountas et al. / Procedia Structural Integrity 41 (2022) 638–645 Author name / Structural Integrity Procedia 00 (2019) 000–000

644

7

(b) LT x DA

(a) LT x NT

0.30

0.30

> – – – – – < 6 6 8 8 10 10 12 12 14 14 16 16 (MPa) UTS

> – – – – – < 6 6 8 8 10 10 12 12 14 14 16 16 (MPa) UTS

0.25

0.25

0.20

0.20

LT (mm)

LT (mm)

0.15

0.15

0.10

0.10

0 10 20 30 40 50 60 70 80 90

180

190

200

210

220

DA (deg)

NT (oC)

(c) LT x PS

(d) NT x DA

0.30

220

> – – – – – < 6 6 8 8 10 10 12 12 14 14 16 16 (MPa) UTS

> – – – – – < 6 6 8 8 10 10 12 12 14 14 16 16 (MPa) UTS

0.25

210

0.20

200

NT (oC)

LT (mm)

0.15

190

0.10

180

30

35

40

45

50

0 10 20 30 40 50 60 70 80 90

PS (mm/sec)

DA (deg)

(e) NT x PS

(f) DA x PS

220

90 80 70 60 50 40 30 20 10 0

> – – – – – < 6 6 8 8 10 10 12 12 14 14 16 16 (MPa) UTS

> – – – – – < 6 6 8 8 10 10 12 12 14 14 16 16 (MPa) UTS

210

200

NT (oC)

DA (deg)

190

180

30

35

40

45

50

30

35

40

45

50

PS (mm/sec)

PS (mm/sec)

Fig. 3. (a) Experimental vs predicted results for UTS (MPa), (b) Probability plot of residuals at 95% c.i. (Anderson-Darling test).

4. Conclusions and future perspectives In the present paper, the effect of four FFF-related parameters namely layer thickness (LT), nozzle temperature (NT), deposition angle (DA) and printing speed (PS) on UTS (MPa) was examined using the PLA /wood flour (70% / 30%) as printing material. Analysis of experiments was conducted through ANOVA and regression to generate a full quadratic model capable of representing the problem’s variability in terms of the correlation among the aforementioned independent parameters and the response of UTS (MPa). To examine the interaction effects among the four FFF parameters contour plots were investigated and it was observed that discrete regions can be found were parameter settings are advantageous for maximizing UTS of the material under research. The fact that specific regions where beneficial parameter values for maximizing UTS can be found, proves that FFF process should be treated as a single, or even a multi-objective optimization problem (if more than a single response are studied) and should be optimized though the implementation of an intelligent algorithm. This process may assist on finding a set