PSI - Issue 2_A

Liviu Marsavina et al. / Procedia Structural Integrity 2 (2016) 1861–1869 Author name / Structural Integrity Procedia 00 (2016) 000–000

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This approach works under the hypothesis that the control volume remains the same it’s; this assumption has been made only to prove that the PUR foams can be treated as a brittle materials and the SED approach can be applied, in fact the strain energy density defined through eq. (3) differs less than ± 8% from the numerical strain energy density. It’s possible to define a new value of critical energy density for each density that permit to decrease the errors, in fact more than 95 % of the results are contained between ± 15 %, so the new values of W c fit better the results. 7. Acknowledgments The experimental results presented here were performed under the Grant of the Romanian National Authority for Scientific Research, CNCS-UEFISCDI, project PN-II-ID-PCE-2011-3-0456, contract number 172/2011. Mr. Alberto Piccotin was supported by ERASMUS program to carry on a research stage at University Politehnica Ashby, M.F., 2005. Cellular solids – scaling of proprieties, in: M. Scheffler, P. Colombo (Eds.), Cellular Ceramics, Structure, Manufacturing, Properties and Applications, Wiley-VCH Verlag Gmbh & Co., 2005, 3–17. ASTM D 1622-08, 2008. Standard Test Method for Apparent Density of Rigid Cellular Plastics. ASTM E-1876-01, 2001. Standard Test Method for Dynamic Young’s Modulus, Shear Modulus, and Poisson’s Ratio by Impulse Excitation Technique of Vibration. Ayatollahi, M.R., Aliha, M.R.M., Saghafi, H., 2011. An improved semi-circular bend specimen for investigating mixed mode brittle fracture, Eng. Fract. Mech. 78, 110–123. Ayatollahi, M.R., Torabi, A.R., 2009. A criterion for brittle fracture in U-notched components under mixed-mode loading, Eng. Fract. Mech. 76 1883– 1896. Berto, F., Lazzarin, P., 2009. A review of the volume-based strain energy density approach applied to V-notches and welded structures, Theor. Appl. Fract. Mec. 52, 183-194. Berto, F., Lazzarin, P., Gómez, F. J., Elices, M., 2007. Fracture assessment of U-notches under mixed mode loading: two procedures based on the ‘equivalent local mode I’ concept, Int. J. Fracture, 148 (2007) 415-433. EN ISO 527:2012. Plastics-Determination of Tensile Properties. Gibson, L.J., Ashby, M.F., 1997. Cellular Solids, Structure and Properties, second ed., Cambridge University Press. Gómez, F. J., Elices, M., Berto, F., Lazzarin ,P., 2007. Local strain energy to assess the static failure of U-notches in plates under mixed mode loading, Int. J. Fracture 145, 29-45. http://www.necumer.com/index.php/en/produkte-2/board-materials.html, 2014. Kipp, M.E., Sih, G.C., 1975. The strain energy density failure criterion applied to notched elastic solids, Int. J. Solids Struct. 11, 153-173. Lazzarin, P., Berto, F., 2005. Some expressions for the strain energy in a finite volume surrounding the root of blunt V-notches, Int. J. Fracture 135, 161-185. Lazzarin, P., Berto, F., Elices, M., Gómez, F. J., 2009. Brittle failures from U- and V-notches in mode I and mixed, I+II, mode: a synthesis based on the strain energy density averaged on finite-size volumes, Fatigue Fract. Eng. M. 32, 671-684. Lazzarin, P., Berto, F., Gómez, F. J., Zappalorto, M., 2008b. Some advantages derived from the use of the strain energy density over a control volume in fatigue strength assessments of welded joints, Int. J. Fatigue 30, 1345-1357. Lazzarin, P., Filippi, S., 2006. A generalized stress intensity factor to be applied to rounded V-shaped notches, Int. J. Solids Struct. 43, 2461– 2478. Lazzarin, P., Livieri P., Berto F., Zappalorto M., 2008a. Local strain energy density and fatigue strength of welded joints under uniaxial and multiaxial loading, Engng. Fract. Mech. 75, 1875-1889. Lazzarin, P., Zambardi, R., 2001. A finite-volume-energy based approach to predict the static and fatigue behavior of components with sharp V shaped notches, Int. J. Fracture 112, 275- 298. Marsavina, L., 2010. Fracture mechanics of cellular solids, in: H. Altenbach, A. Ochsner (Eds.), Cellular and Porous Materials in Structures and Processes, Springer, Wien, 1–46. Marsavina, L., Constantinescu, D.M., Linul, E., Apostol, D.A., Voiconi, T., Sadowski, T., 2014a. Refinements on fracture toughness of PUR foams, Eng. Fract. Mech. 129, 54–66. Marsavina, L., Constantinescu, D.M., Linul, E., Apostol, D.A., Voiconi, T., Sadowski, T., 2014b. Evaluation of mixed mode fracture for PUR foams, Proc. Mater. Sci. 3, 1342–1352. Negru, R., Marsavina, L., Filipescu, H., Căplescu, C., Voiconi, T., 2015. Application of the volume-based strain energy density method for brittle fracture of PUR materials. Negru, R., Marsavina, L., Filipescu, H., Pasca, N., 2013. Investigation of mixed mode I/II brittle fracture using ASCB specimen, Int. J. Fract. 18, 155–161. Timisoara. References

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