Double torsion testing machine to determine the subcritical fracture index in rocks

  • Pedro-J. Díaz Universidad Industrial de Santander, Bucaramanga, Colombia
  • Jenny-M. Carvajal Ecopetrol – Instituto Colombiano del Petróleo, Piedecuesta, Colombia
  • Miguel-Fernando Palencia-Muñoz Universidad Industrial de Santander, Bucaramanga, Colombia
Keywords: Subcritical fracture index, Stress intensity factor, Critical load speed


This paper  discusses  the  design  methodology  applied to  build  a  testing machine  to  determine  the  sub-critical  fracture  index  in a  rock, based  on  double  torsion  testing in order to characterize  naturally  fractured formations  such  as  those  located  in the  Colombian Llanos Foothill Basin .  These  formations  have  been  subjected  to cyclic loads  over time,  causing  fractures  that  trend  to spread  at sub-critical  stress intensity values.  Similarly,  it  presents  the results of  testing conducted  on  nine  specimens of  the Tambor  Formation  from  2  different  outcrops  to establish  the testing traceability in the equipment.


A. Collins, J. (2003). Mechanical Design Of machine Ele- ments and Machines.Jhon Wiley and Sons.

A.G., E. (s.f.). A method for evaluating the time-dependent failure characteristics.

ASTM D6026-06.Standard Practice for Using Significant
Digits in Geotechnical Data.
ASTM-D4543-08.Standard Practices for Preparing Rock Core as Cylindrical Test Specimens and Verifying Conformance to Dimensional and Shape Tolerances.

Atkinson, B. K. (1984). Subcritical crack growth in geological materials. J. Geophys., Res. 89, 4077-4114.

Atkinson, B., & Meredith, P. G. (1987).The theory of subcriti- cal crack growth with applications to rocks and minerals, in Fracture Mechanics. 111-116: Academic Press, London.

Cho, K., & Gent, A. N. (1985).An improved torsional method for determining the fracture toughness of stiff materials and of adhesive joints. International. J. Fracture, 239-244.

Evans, A. (1972). A method for evaluating the time-dependent failure characteristics. J. Materials Scie., 7(10), 1137-

G. Budynas, R., & Keith Nisbett, J. (2008). Diseño en Inge- niería Mecánica de Shigley. McGrawHill.

Gerry, D., &Outwater, J. (1969). On the fracture energy, rehearing velocity and refracture energy of cast epoxy resin. J. Adhesion, 1:290 298.

Holder, J., Olson, J. E., & Zeno, P. (2001).Experimental determination of subcritical crack growth.Geophysical Research Letters , 599-602.

Kies, J., & Clark, A. (1969).Kies JA, Clark ABJ. Fracture propagation rates and times to fail proof stresses in bulk glass. Proceedings of the Second International Conference on Fracture; 483-491.

Ko, T. Y. (2008). Experimental study of subcritical crack growth under mode I, mode II and mode III loading.The University of Arizona, Department of Mining and Geo- logical Engineering, Tucson, AZ, U.S.A.

M. Ciccotti, G. G. (2000). The double torsion loading con- figuration for fracture propagation: an improved metho- dology for the load-relaxation at constant displacement. Dipartimento di Fisica, Settore di Geofisica, UniversitÁ di Bologna.

M. Saadaouia P. Reynauda, G. F. (2000). Slow crack growth study of plaster using the double torsion method. Ceramics International 26 (4), 435 -439.

Nara, Y. (2006). Subcritical Crack Growth in Rock.COE Postdoctoral Fellow, Division of Field Engineering for Environment.

Outwater, J. O., & Gerry, D. J. (1966). On the fracture en- ergy of glass NRL Interim Contract Report.University of Vermont, Burlington.

Park, N. (2006). Discrete Element Modeling of Rock Frac- ture Behavior: Fracture Toughness and Time-Dependent Fracture Growth, Dissertation by Doctor Philosophy.The University of Texas at Austin.

Sun, Z., & Ouchterlony, F. (1999). Fracture toughness of stripa granite cores. International J. Rock Mechanics and Min- ing Science &GeomechanicsAbstracts, 23 (6), 399-409 .

Whittaker BN, S. R. (1992). Rock Fracture Mechanics - Prin- ciples, Design and Applications. Elsevier Science, 90-107.

Williams, D., & Evans, A. (1973-1). A simple method for studying slow crack growth.J. Test Eval , 264-270.
How to Cite
Díaz, P.-J., Carvajal, J.-M., & Palencia-Muñoz, M.-F. (2011). Double torsion testing machine to determine the subcritical fracture index in rocks. CT&F - Ciencia, Tecnología Y Futuro, 4(3), 37-46.


Download data is not yet available.
Scientific and Technological Research Articles