PSI - Issue 28

A. Saoud et al. / Procedia Structural Integrity 28 (2020) 491–501 Author name / Structural Integrity Procedia 00 (2019) 000–000

501

11

6

5

4

3

2

1

0

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

stress intensity factor (MPa.√m)

(a/W)

Fig .12. Comparison between the stress intensity factor of the test studied and 4ENF test

The two figures show an acceptable agreement between the two tests with a low ratio. This report is well justified given the dispersive nature of the wood as well as the difficulty we had during the acquisition of data from the 4ENF test. 6. Conclusion The test protype used to study the behaviour of wood subjected to shear stress in the longitudinal plane has been developed. The experimental protocol of this test was applied to Eucalyptus Grandis wood. We were able to determine GIIC and KIIC from the typical recording of the load-displacement curve during stable crack propagation, which is not feasible for the 4ENF, 3ENF and ELS tests. These results were compared with the 4ENF test and the literature where we concluded that our approach presents an ease of production and application of the tests and also the recording of crack propagation. Contrary to other tests, the comparison of the results shows a high degree of agreement. References A.Daya, «Etude des contraintes de croissance des arbres,» Thése Metz, 2006. Loulidi, «Etude statistique des propriétés physico-mécaniques de quatre essences d’Eucalyptus – Approche expérimentale et numérique pour l’étude de la ténacité à la rupture en mode I sur des éprouvettes DCB du bois d’E. gomphocephala,» Thése ENSEM, Casablanca, 2013. Yoshihara H, «Measurement of mode II fracture toughness of wood by the end-notched flexure test,» J Wood Sci 2000, p. 46:273–8. M.A.L.Silvaa M.F.S.F.de MourabJ.J.L .Moraisa Numerical analysis of the ENF test for mode II wood fractureComposites Part A: Applied Science and Manufacturing Volume 37, Issue 9, September 2006, Pages 1334-1344