PSI - Issue 56

Cosmin Florin POPA et al. / Procedia Structural Integrity 56 (2024) 176–183 Popa Cosmin-Florin/ Structural Integrity Procedia 00 (2019) 000–000

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In the other specimen in stage 2 Fig. 9 b), the engineering shear strain is distributed in a circle area, the cracks appeared on both sides of the fracture area, which can be seen in the last stage, Fig. 9 c). The maximum value is above the 5% strain due to the contour layers.

Fig. 10 Force - Displacement curves for a) specimens without contour and b) for specimens with contours

Fig. 10 depicts the force-displacement graph for both specimen types. In Fig 10.a, the results for the specimens contour it could be observed that the values of force are scattered. The results are clustered in groups of two, this behavior may be due to the printing process or microcracks, which initiate at the layers interface. On the other hand, for the specimens with contour, the results are very close to each other, and the behavior is the same for all specimens.

Fig. 11 Comparison of shear strength between the two types of specimens

Fig. 11 presents a comparison of the shear strength between two types of specimens. The contour specimens exhibited a 34% higher shear strength than the specimens without contour. The contour has a significant influence on the results. The error bars indicate that the values for specimens without contour are highly scattered, whereas the values of specimens with contour are much less scattered. 4. Conclusions The objective of this study was to investigate the difference in shear behavior between specimens with and without contour. The contoured specimens exhibited a shear strength of 27.73 MPa, which is 34% higher than that of the un contoured specimens (18.24 MPa). Additionally, the contoured specimens showed a greater elongation at fracture. These results suggest that contouring should not be ignored when designing and manufacturing 3D-printed parts.