PSI - Issue 13

Odounga Bernard et al. / Procedia Structural Integrity 13 (2018) 347–352

352

6

Odounga Bernard / Structural Integrity Procedia 00 (2018) 000–000

Fig. 6. Critical energy release rate Gc as a function of the crack length for the thickness b = 20 mm and the angle α = 15 0 (mode 2).

Fig. 7. Minimum values of the critical energy release rate G ic of the three species (mode 1 and 2).

4. Conclusion

In this paper, MMCG specimens with a reduced thickness b = 20 mm were used to study the mixed mode cracking (angle α = 15 0 ) of iroko, okume and padouk. An electromechanical testing machine was used to perform tensile tests. The grid method has been used to track the opening of the crack and track the location of the tip. The decoupling of the modes gives the values of G I and G II . The energy release rate calculated by the imposed displacement method of compliance show a predominance of the mode 1. Typical displacement and strain maps, curves showing load as a function of the crack opening, and energy release rate as a function of the crack length were presented. The mean minimum energy release rate values G ic were calculated and compared for the three species. The results show that there is an influence of the density on the failure of these species.

References

Cop 23. United Nations Conference on Climate Change. Bonn in Germany, 6-17 November 2017. https: // cop23.com.fj / . Gre´diac, M., Sur, F., Blaysat, B., 2016. The Grid Method for In-plane Displacement and Strain Measurement: A Review and Analysis. Strain: An International Journal for Experimental Mechanics, number 3, Vol. 52, pp. 205-243. Odounga, B., Moutou Pitti, R., Toussaint, E., Gre´diac, M., 2017. Experimental fracture analysis of tropical species using the grid method. Int: Fracture, Fatigue, Failure and Damage Evolution, Springer 8, pp. 9-14.