PSI - Issue 28

8

Amal Saoud/ Structural Integrity Procedia 00 (2019) 000–000

A. Saoud et al. / Procedia Structural Integrity 28 (2020) 491–501

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The fracture surface of Mode II is characterized by a severe twisting, tearing and unfolding of the tracheal walls, the loosening of the fibers is more apparent as can be seen in Fig. 7. The results of the SEM studies thus allow concluding that for a gasoline that the rupture is a pure mode II.

Fig. 7. Mode II fracture facies with a magnification of 170.

4. Calculation of wood toughness using the 4ENF test. In order to compare the results obtained using our modified specimen, we considered it important to carry out the most common test for the study of this mode of failure for the wood material. In this part, we will explain the results of the 4 ENF test carried out on Eucalyptus Grandis. 4.1 Load-displacement curves The specimens are notched along the longitudinal direction in the TL plane, so that the rings are parallel in the TR plane. The speed of movement of the cross member selected for the test is 0.2 mm / min. The test is interrupted when a sudden drop in load is observed. Fig 8 show typical load displacement curves for notch lengths 80 mm.

Fig. 8. Displacement load curve for a notch length a = 80 mm