Issue 50

M.R.M. Aliha et alii, Frattura ed Integrità Strutturale, 50 (2019) 602-612; DOI: 10.3221/IGF-ESIS.50.51 609  The fracture toughness of samples was dependent on the location of specimen cutting from the femur and the frontal part of the bone had stronger crack growth resistance in comparison with the other parts along the hoop direction.  The fracture toughness results obtained from the left and right femur bone were nearly identical.  The fracture energy ( G f ) required for breaking and splitting the bone samples were also measured and it was found that there is a nearly linear relation between the fracture toughness ( K Ic ) and fracture energy ( G f ) for the tested femur bone. Therefore, the fracture energy of tested bone can be estimated in terms of fracture toughness value and vice versa.  The natural and noticeable scatter observed in the fracture behavior of tested bone (i.e. fracture toughness and fracture energy) is mainly attributed to randomly distribution of different parts (such as voids, canals and secondary osteons) existing in the micro-structure of bone material. R EFERENCES [1] Norman, T. L., Vashishth, D., & Burr, D. B. (1995). Fracture toughness of human bone under tension. Journal of biomechanics, 28(3), pp. 313-320. DOI: 10.1016/0021-9290(94)00069-G [2] Barrero, M., & Adams, D. J. (2004). A Fracture Toughness Test for Rat Cortical Bone (Doctoral dissertation, University of Connecticut). [3] Behiri, J. C., & Bonfield, W. (1989). Orientation dependence of the fracture mechanics of cortical bone. Journal of biomechanics, 22(8), pp. 863-867. DOI: 10.1016/0021-9290(89)90070-5 [4] Lucksanasombool, P., Higgs, W. A. J., Higgs, R. J. E. D., & Swain, M. V. (2001). Fracture toughness of bovine bone: influence of orientation and storage media. Biomaterials, 22(23), pp. 3127-3132. DOI: 10.1016/S0142-9612(01)00062-X [5] Yan, J., Clifton, K. B., Mecholsky, J. J., & Gower, L. A. (2007). Effect of temperature on the fracture toughness of compact bone. Journal of biomechanics, 40(7), pp. 1641-1645. DOI: 10.1016/j.jbiomech.2006.07.011 [6] Nalla, R. K., Kruzic, J. J., Kinney, J. H., & Ritchie, R. O. (2005). Mechanistic aspects of fracture and R-curve behavior in human cortical bone. Biomaterials, 26(2), pp. 217-231. DOI: 10.1016/j.biomaterials.2004.02.017 [7] Zimmermann, E. A., Launey, M. E., Barth, H. D., & Ritchie, R. O. (2009). Mixed-mode fracture of human cortical bone. Biomaterials, 30(29), pp. 5877-5884. DOI: 10.1016/j.biomaterials.2009.06.017 [8] Morais, J. J. L., De Moura, M. F. S. F., Pereira, F. A. M., Xavier, J., Dourado, N., Dias, M. I. R., & Azevedo, J. M. T. D. (2010). The double cantilever beam test applied to mode I fracture characterization of cortical bone tissue. Journal of the Mechanical Behavior of Biomedical Materials, 3(6), pp. 446-453. DOI: 10.1016/j.jmbbm.2010.04.001 [9] Pereira, F. A. M., De Moura, M. F. S. F., Dourado, N., Morais, J. J. L., Xavier, J., & Dias, M. I. R. (2017). Direct and inverse methods applied to the determination of mode I cohesive law of bovine cortical bone using the DCB test. International Journal of Solids and Structures, 128, pp. 210-220. DOI: 10.1016/j.ijsolstr.2017.08.028 [10] Pereira, F. A. M., de Moura, M. F. S. F., Dourado, N., Morais, J. J. L., Xavier, J., & Dias, M. I. R. (2018). Determination of mode II cohesive law of bovine cortical bone using direct and inverse methods. International Journal of Mechanical Sciences, 138, pp. 448-456. DOI: 10.1016/j.ijmecsci.2018.02.009 [11] Silva, F. G. A., de Moura, M. F. S. F., Dourado, N., Xavier, J., Pereira, F. A. M., Morais, J. J. L., ... & Judas, F. M. (2017). Fracture characterization of human cortical bone under mode II loading using the end-notched flexure test. Medical & biological engineering & computing, 55(8), pp. 1249-1260. DOI: 10.1007/s11517-016-1586-6, [12] Silva, F. G. A., de Moura, M. F. S. F., Dourado, N., Xavier, J., Pereira, F. A. M., Morais, J. J. L., & Dias, M. I. R. (2016). Mixed-mode I+ II fracture characterization of human cortical bone using the Single Leg Bending test. Journal of the mechanical behavior of biomedical materials, 54, pp. 72-81. DOI: 10.1016/j.jmbbm.2015.09.004 [13] Zimmermann, E. A., Launey, M. E., & Ritchie, R. O. (2010). The significance of crack-resistance curves to the mixed- mode fracture toughness of human cortical bone. Biomaterials, 31(20), pp. 5297-5305. DOI: 10.1016/j.biomaterials.2010.03.056 [14] Margevicius, R. W., Riedle, J., & Gumbsch, P. (1999). Fracture toughness of polycrystalline tungsten under mode I and mixed mode I/II loading. Materials Science and Engineering: A, 270(2), pp. 197-209. DOI: 10.1016/S0921-5093(99)00252-X [15] Suresh, S., Shih, C. F., Morrone, A., & O'Dowd, N. P. (1990). Mixed ‐ mode fracture toughness of ceramic materials. Journal of the American Ceramic Society, 73(5), pp. 1257-1267. DOI: 10.1111/j.1151-2916.1990.tb05189.x