PSI - Issue 25

Dalbir Singh et al. / Procedia Structural Integrity 25 (2020) 159–171 Dalbir singh/ Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 4. Samples exposed to OX38 for 15, 30 and 45 days respectively

2.1. Tensile-Test The tensile tests were performed on the Instron 3382 Universal Testing Machine (Fig.5), having cross-head speed of about 5 mm/min. The tensile specimens were cut from the manufactured laminate as per the ASTM standard D638, which results in a specimen size of 165 x 19 x 3.2 mm 3 . These specimens were also affixed with aluminium tabs; of dimensions 32.86 x 19 x 3 mm 3 , at their ends for better grip during testing is shown in Fig.5. The sample was placed between the jaws of the machine. The required load was applied to the sample to pull it apart. The required bar graph was plotted to study the required mechanical characteristics.

Fig.5. Tensile machine setup for testing the specimens

2.2. Flexural testing The flexural tests were also performed on the Instron 3382 Universal Testing Machine (Fig. 6), having cross head speed about 5 mm/min. The specimens used in the experiments were cut from the manufactured laminates as per ASTM standard D790-2. The three-point bending (3 PB) tests were performed on specimens cut to a size of 127 x 12.7 x 3.2 mm 3 . All 3PB tests were also carried out at room temperature (~25 0 C), the support span or the distance between the supports was 51.2 mm; which is 16 times the thickness of the specimen and, for each condition, and three specimens were tested. Flexural machine setup for testing the specimens is shown in Fig.11. Flexural strength was calculated by the nominal stress at the mid-span section, obtained using the maximum value of the load. The nominal flexural stress was calculated using Eq. = 2 3 ℎ 2