PSI - Issue 42

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Marouene Zouaoui et al. / Procedia Structural Integrity 42 (2022) 680–686 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig.3. SENB specimens used in this study. (a) Solid specimen, (b) Honeycomb cell pattern, (c) Auxetic cell pattern at 0° and (d) Auxetic cell pattern at 90°.

The comparison is based on the fracture energy evaluation and the index performance that will be defined in the next section. The effect of cell pattern will be highlighted by using a reference solid specimen as shown in Fig.3 (a). The unit cell dimensions shown in Table 1 are calculated using the formulas in Fig. 4. The geometrical parameters of both are chosen so that the total surface area of the specimens with a cell pattern is equivalent.

Fig. 4. Unit cell dimensions. (a) 1 denotes the unit honeycomb cell surface and (b) 2 denotes the unit auxetic cell surface. Table 1. Cell patterns definition and specimens’ specifications . Specimen a = one cell surface area (mm²) Number of cells Total surface area (mm²) Average weight (g) Number of specimens Solid - - 7165 540 1 Honeycomb 1 140 3891.8 294.43 ± 3.66 3 Auxetic 0° 2 140 3736.4 294.9 ± 0.42 3 Auxetic 90° 2 132 3232.68 286.26 ± 2.77 3