Issue 47

S. K. Kourkoulis et alii, Frattura ed Integrità Strutturale, 47 (2019) 247-265; DOI: 10.3221/IGF-ESIS.47.19 264 The above analysis clearly indicates that the thickness of the CSR-specimens plays an important role, which should not be ignored in case the CSR-test is to be used for the determination of the tensile strength. Given that the analytic solution cannot be applied for intermediate states between plane-stress and plane-strain conditions, Eqs.(22, 23) must be handled with caution. Research in progress [27] aims to provide correction factors, following a hybrid analytic-numerical approach. Coming to an end, it can be safely stated that the CSR-test is indeed a flexible alternative for the determination of the tensile strength of brittle materials, the potentialities of which should be further explored, both experimentally (for specimens made of rocks and rock-like materials) and numerically (in the direction of quantifying the role of additional parameters). R EFERENCES [1] Carneiro, F. L. L. B. (1943). A new method to determine the tensile strength of concrete, Proc. 5 th Meeting of the Brazilian Association for Technical Rules, 3d. Section, 16 September 1943, pp. 126–129 (in Portuguese). [2] Akazawa, T. (1943). New test method for evaluating internal stress due to compression of concrete (the splitting tension test) (part 1), J. Japan Soc. Civil Engrs, 29, pp. 777–787. [3] Hondros, G. (1959). The evaluation of Poisson’s ratio and the modulus of materials of a low tensile resistance by the Brazilian (indirect tensile) test with particular reference to concrete, Aust. J. Appl. Sci., 10, pp. 243–268. [4] Markides, Ch. F., Pazis, D.N., Kourkoulis, S. K. (2010). Closed full-field solutions for stresses and displacements in the brazilian disk under distributed radial load, Int. J. Rock Mech. Min. Sci, 47(2), pp. 227–237. [5] Markides, Ch. F., Kourkoulis, S. K. (2012). The stress field in a standardized Brazilian disc: The influence of the loading type acting on the actual contact length, Rock Mech. Rock Eng, 45(2), pp. 145–158. [6] Kourkoulis S. K., Markides, Ch. F., Chatzistergos, P. E. (2012). The Brazilian disc under parabolically varying load: Theoretical and experimental study of the displacement field, Int. J. Solids Struct., 49(7-8), pp. 959–972. [7] Markides, Ch. F., Pazis, D.N., Kourkoulis, S. K. (2010). The Brazilian disc under non uniform distribution of radial pressure and friction, Int. J. Rock Mech. Min. Sci, 50, pp. 47–55. [8] Kourkoulis, S. K., Markides, Ch. F., Hemsley, J. A. (2013). Frictional stresses at the disc-jaw interface during the stand- ardized execution of the Brazilian disc test, Acta Mechanica, 224(2), pp. 255–268. [9] Kourkoulis, S. K., Markides, Ch. F., Chatzistergos, P. E. (2012). The standardized Brazilian disc test as a contact problem, Int. J. Rock Mech. Min. Sci, 57, pp.132–141. [10] Hobbs, D. W. (1964). The tensile strength of rocks, Int. J. Rock. Mech. Min. Sci., 1, pp. 385–396. [11] Fairhurst, C. (1964). On the validity of the ‘Brazilian’ test for brittle materials, Int. J. Rock Mech. Min. Sci., 1, pp. 535–546. [12] Hobbs, D. W. (1965). An assessment of a technique for determining the tensile strength of rock, Brit. J. Appl. Phys., 16, pp. 259–268. [13] Hooper, J. A. (1971). The failure of glass cylinders in diametral compression. J. Mech. Phys. Solids, 19, pp. 179–200. [14] Mellor, M., Hawkes, I. (1971). Measurement of tensile strength by diametral compression of discs and annuli, Eng. Geol., 5, pp. 173–225. [15] Ripperger, E., Davis, N. (1947). Critical stresses in a circular ring (Paper no 2308), Trans. Am. Soc. Civil Engrs, 112, pp. 619–627. [16] Jaeger, J.C., Hoskins, E. R. (1966). Stresses and failure in rings of rock loaded in diametral tension or compression. Brit. J. Appl. Phys., 17, pp. 685–692. [17] Wang, Q. Z., Jia, X. M., Kou, S. Q., Zhang, Z. X., Lindqvist, P. A. (2004). The flattened Brazilian disc specimen used for testing elastic modulus, tensile strength and fracture toughness of brittle rocks: analytical and numerical results. Int. J. Rock Mech. Min. Sci., 41(2), pp. 245–253. [18] Kuruppu, M. D., Obara, Y., Ayatollahi, M. R., Chong, K. P., Funatsu, T. (2014). ISRM-suggested method for deter- mining the mode I static fracture toughness using semi-circular bend specimen. Rock Mech Rock Eng, 47(1), pp. 267–274. [19] ASTM E399 - 90 (1997). Standard Test Method for Plane-Strain Fracture Toughness of Metallic Materials - A5. Special Requirements for the Testing of the Arc-Shaped Tension Specimen. [20] Muskhelishvili, N. I. (1963). Some Basic Problems of The Mathematical Theory of Elasticity, Noordhoff, Groningen. [21] Golovin, Kh. (1882). A static problem of the elastic body. Minutes of the Technological Institute, St. Petersburg, 1880-1881, St. Petersburg. [22] Love, A. E. H. (1927). A Treatise on the Mathematical Theory of Elasticity, 4 th ed., Cambridge, 1927.