PSI - Issue 56

Balichakra Mallikarjuna et al. / Procedia Structural Integrity 56 (2024) 160–166 Mallikarjuna et al./ Structural Integrity Procedia 00 (2019) 000 – 000

163

4

The specimen is a cube with dimensions 12.7 x 12.5 x 25.4 mm 3 . The flexural strength of samples was built with a size of 3.2 x 12.7 x 127 mm according to ASTM D790 standard and tested in UTM-Electronic type. The printed sample's picture is shown in Fig. 1 (c). Finally, the impact sample prepared following the ASTM D256 standard is shown in Fig. 1 (d). The standard specimen dimensions are 63.5 mm x 12.7 mm with a notch of 22.5 degrees and a radius of 0.25 mm.

3. Results and discussions 3.1 Tensile Strength

The Ultimate Tensile Strength (UTS) of 9 different samples varies from 24.9 MPa to 36 MPa, as shown in Fig. 2. A least tensile strength has been noted for S1, i.e., 20%, 225 ℃ and 20 mm/s and the highest for S9, i.e., 30%, 245 ℃ and 25 mm/s. It can be observed that with an increase in infill density, there is an increase in ultimate tensile strength. S1, S2 and S3 have the least infill density of 20% and display the least UTS compared to the other 6 specimens. The same trend can be noted for the other two process parameters. The difference in the UTS is minimal in S4 and S9; this implies that we can achieve almost similar UTS with less infill density.

Comparison of tensile strengths

10 15 20 25 30 35 40

0 5

Ultimate tensile strength (MPa)

S1

S2

S3

S4

S5

S6

S7

S8

S9

Sample designation

Fig. 2. Comparison of tensile strengths of various samples built under process conditions.

3.2. Flexural Strength The flexural strength varies from 46.7 MPa to 54.8 MPa, as presented in Fig. 3. The Highest flexural strength has been observed for S8 and the least for S7, which have the same infill density of 30%. It was found that the S3, S6, and S8 have shown the highest flexural strength. Also, S4, S5, and S6 have better strength in the other two groups (S1, S2, S3 and S7, S8, and S9). It was observed that the specimen's flexural strength is more than tensile strength.