13th International Conference on Fracture June 16–21, 2013, Beijing, China -7- natural crack in the specimen causing a lower scatter in the experimentally obtained fracture loads. Observed fracture surface shows that surface roughness of the cracked chevron notched specimens is relatively low for the tested white crystalline rock (see Fig. 6). Meanwhile, it is finally recommended that similar fracture tests are performed on the SCB specimens having straight cracks and the experimental results are compared when these two different methods are used for generating the artificial crack. References [1] M. F. Kanninen and C. H. Popelar C. H, Advanced Fracture Mechanics”, Oxford Engineering Science Series, Vol. 15. Oxford University Press, New York, 1985. [2] Matsuki K, Hasibuan S. S, Takahashi H, “Specimen size Requirements for determining the inherent fracture toughness of rocks according to ISRM suggested Methods”, Journal of applied mechanics, Vol. 18, 1991, pp. 413-427. [3] F. Quchterlony, ISRM Suggested methods for determining fracture toughness of rocks, Int. J. Rock. Mech. Min. Sci. & Geomech. Abstr, Vol. 25, 1988, pp. 264-294. [4] ISRM Testing Commission (co-ordinator: RJ Fowell), Suggested method for determining mode I fracture toughness using cracked chevron notched Brazilian disc (CCNBD) specimens: Int J Rock Mech Min Sci & Geomech Abstr, 32, 1995, pp. 57–64. [5] K.P. Chong, M.D. Kuruppu and J.S. Kuszmual, Fracture toughness determination of layered materials: Engineering Fracture Mechanics, 28(1), 1987, pp. 43-54. [6] M.D. Kuruppu, K.P. Chong, Fracture toughness testing of brittle materials using semi-circular bend (SCB) specimen, Engineering Fracture Mechanics, 2012, pp. 1-18 . [7] M.D. Kuruppu, Fracture toughness measurement using chevron notched semi-circular bend specimen, Int J Fract, Vol. 86(4), 1997, pp33–38 . [8] M.D. Kuruppu, Stress intensity factors of chevron-notched semi-circular specimens, In: Basu et al., editors. Proc 3rd APCOM, the aust inst of min & met. 1998, pp. 111–112. [9] M.D. Kuruppu, Fracture toughness testing of geomaterials using semi-circular specimen, In: Proc geo engng, Technomic Publishing Lancaster, PA; [Proc in CD], vol. 2, 2000. [10 I.L. Lim, I.W. Johnston, S.K. Choi, J.N. Boland, Fracture testing of a soft rock with semi-circular specimens under three-point loading, Part 1 – Mode I. Int J Rock Mech Min Sci, Vol. 31, 1994, pp. 185–97. [11] I.L. Lim, I.W. Johnston, S.K. Choi, Stress intensity factors for semi-circular specimens under three-point bending, Eng. Fract. Mech., 44, 1993, pp. 363–382. [12] Bluhm J. I., Slice synthesis of a three dimensional Work of Fracture specimen, Engng Fracture Mech. 7, 1975, pp. 593-604. [13] Q.Z. Wang, X.M. Jia, L.Z. Wu, Wide-range stress intensity factors for the ISRM suggested method using CCNBD specimens for rock fracture toughness tests. Int J Rock Mech Min Sci, 41, 2004, pp. 709–16.
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