PSI- Issue 9

Liviu Marsavina et al. / Procedia Structural Integrity 9 (2018) 47–54 Author name / Structural Integrity Procedia 00 (2018) 000–000

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4. Conclusion This paper presents experimental results obtained for mode I and mode II fracture toughness. The fracture toughness tests were performed on Single Edge Notched Bend (SENB) specimen for mode I, respectively on Compact Shear (CS) specimens for mode II loading. In this study, we propose a coupling between experimental and analytical approaches for characterizing the fracture parameters in opening mode for the Particleboard material. Using the experimental displacements measured by DIC the Crack Relative Displacement Factor was estimated. At the same time, the Stress Intensity Factor was calculated analytically. Then the fracture energy was calculated by coupling these two fracture factors. Consequently, the fracture parameters such as Crack Relative Displacement Factor, Stress Intensity Factor and fracture energy were estimated without the knowledge of the material properties. Furthermore the proposed formalism allows optimize the experimental measurements and separate the mixed modes. Thus, the part of each mode in the fracture process can be estimated. The present study allows to conclude that the Crack Relative Displacement Factor coupled with Stress Intensity Factor provides a good estimation of fracture energy without the knowledge of the actual properties of material. This approach allows considering the assessment of fracture parameters for the real structures. Acknowledgement Part of the experimental work was carried out in the framework of the grant from the Romanian National Authority for Scientific Research, CNCS – UEFISCDI, project code PN-III-P1-1.1-MCD-2016-0076, contract number 41/8.11.2016, which supports the mobility of Dr. Pop at the University Politehnica Timișoara. References Anderson, TL., 1995. Fracture Mechanics. Fundamentals and Applications. Second Edition. CRC Press LLC. Budiansky E, Rice J. 1973. Conservation laws and energy release rates. J Appl Mech 40, 201–203. Cherepanov G., 1967. Crack propagation in continuous media. J Appl Mech 31, 476–488. Erdogan F., 1962. On the stress distribution in plates with collinear cuts under arbitrary loads. In: Proceedings of the fourth US national congress of applied mechanics 1, 547–574. Beer, P., Gindl, M., Stanzl-Tschegg, S., 2008. Wedge splitting experiments on three-layered particleboard and consequences for cutting, Holz als Roh- und Werkstoff 66, 135-141. Beer, P., Sinn, G., Gindl, M., Stanzl-Tschegg, S., 2005. Work of fracture and of chips formation during linear cutting of particle-board, Journal of Materials Processing Technology 159, 224–228. Craciun, E.-M., Sadowski, T., Marsavina, L., Rabaea, A., 2014. Mathematical aspects regarding cracks behavior in wood composites, Key Engineering Materials 601, 108-111. Danielsson, H., 2013. Perpendicular to grain fracture analysis of wooden structural elements. Models and Applications, PhD Thesis, Lund.. Dubois F, Chazal C, Petit C., 2002. Viscoelastic crack growth process in wood timbers: an approach by the finite element method for mode I fracture. Int J Fract 113, 367–388. Dubois F, Petit C., 2005. Modeling of the crack growth initiation in viscoelastic media by the Gθ integral. Eng Fract Mech 72, 2821–2836. Franke, B., Quenneville, P., 2014. Analysis of the fracture behavior of Radiata Pine timberand Laminated Veneer Lumber, Engineering Fracture Mechanics 116, 1–12. Hild, F., and Roux, S., 2006. Measuring stress intensity factors with a camera: integrated digital image correlation (I-DIC). Comptes Rendus Mécanique, 334, 8–12. Irwin GR., 1957. Analysis of stresses and strains near the end of a crack traversing a plate. J Appl Mech 24, 361–364. Ilcewicz, L.B., 1979. On the phenomena of fracture in particleboard, Oregon State University. Matsumoto, N., 2008. The Fracture Toughness of Medium Density Fiberboard and other Fiber Bridging Composites, Oregon State University. Matsumoto, N., Nairn, J.A., 2007. Fracture Toughness of MDF and other Materials with Fiber Bridging, Proc. of 22nd Ann. Tech. Conf. of the Amer. Soc. of Composites, Sept. 17-19, Seattle, WA, 1-19. Matsumoto, N., Nairn, J.A., 2009. The fracture toughness of medium density fiberboard (MDF) including the effects of fiber bridging and crack– plane interference, Engineering Fracture Mechanics 76, 2748–2757. Méité M, Pop O, Dubois F, Absi J., 2013. Characterization of mixed-mode fracture based on a complementary analysis by means of full-field optical and finite element approaches. International Journal of Fracture 180, 41-52. Murakami, Y., 1987. Stress Intensity Factors Handbook,” Pergamon Press.