PSI - Issue 3

A.A. Ahmed et al. / Procedia Structural Integrity 3 (2017) 498–507 Author name / Structural Integrity Procedia 00 (2017) 000–000

501

4

2.85mm. The key manufacturing parameters were set as follows: nozzle size=0.4mm, nozzle temperature=240  C, build-plate temperature=60  C, layer height=0.1 mm, shell thickness=0.4mm, fill density=100%, and print speed=30mm/s. Figure 1 shows the technical drawings of the specimens that were manufactured to investigate experimentally both the static strength and the fracture resistance of the additively manufactured PLA being considered. The specimens were manufactured horizontally by setting the manufacturing angle,  p , equal to 0  , 30  , 45  , 60  , and 90  (Fig. 2). In particular, after melting the parent material filaments, they were extruded and deposited, layer upon layer, at ±45  to the reference manufacturing direction, with  p being the angle between the reference manufacturing direction and the longitudinal axis of the specimens (see Figure 2).

Table 1. Summary of the experimental results generated by testing plain specimens of AM PLA.

w n

t

E

 UTS

 P

 0.2%

Code

[mm] 14.95 14.93 14.97 14.85 15.09 14.92 14.87 15.15 15.03 15.06 15.06 15.00 15.16 14.95 15.10

[mm]

[MPa]

[MPa]

[MPa]

[  ]

P_0_2 P_0_3 P_0_4 P_30_1 P_30_2 P_30_3 P_45_1 P_45_2 P_45_3 P_60_1 P_60_2 P_60_3 P_90_1 P_90_2 P_90_3

0 0 0

4.08 4.07 4.21 4.11 4.11 4.04 4.09 4.07 4.04 4.13 4.18 4.08 3.99 3.98 4.15

3189 3265 3251 3136 3450 3357 3426 3342 3348 3180 3251 3235 3421 3399 3193

40.9 42.2 42.0 35.1 40.1 40.3 38.6 40.7 39.1 40.1 40.1 42.4 42.3 40.7 -

41.5 43.1 43.4 37.7 40.8 44.2 42.9 42.5 42.1 39.6 40.9 42.1 46.5 48.0 42.8

30 30 30 45 45 45 60 60 60 90 90 90

Table 2. Summary of the experimental results generated by testing specimens of AM PLA containing crack-like notches.

t

a

w g

K C

 P

 f

Code



[MPa · m 1/2 ]

[mm] 25.03 24.78 24.73 24.98 24.98 24.92 24.93 24.90 24.88 24.83 24.80 24.82 25.06 25.06 24.74

[mm]

[mm]

[MPa]

[  ]

C_0_1 C_0_2 C_0_3 C_30_1 C_30_2 C_30_3 C_45_1 C_45_2 C_45_3 C_60_1 C_60_2 C_60_3 C_90_1 C_90_2 C_90_3

0 0 0

4.22 4.20 4.22 4.21 4.18 4.18 4.16 4.18 4.16 4.18 4.14 4.08 4.04 4.11 4.08

4.67 4.47 4.34 4.86 4.73 4.75 4.72 4.90 4.85 4.63 4.83 4.78 4.75 5.39 4.89

1.131 1.130 1.129 1.134 1.132 1.133 1.132 1.134 1.134 1.131 1.134 1.133 1.132 1.142 1.135

28.4 27.6 28.0 21.0 18.9 21.2 23.0 21.8 21.4 20.6 19.7 20.5 25.8 25.2 28.4

3.9 3.7 3.7 2.9 2.6 2.9 3.2 3.1 3.0 2.8 2.8 2.9 3.6 3.8 4.0

30 30 30 45 45 45 60 60 60 90 90 90