The phenomenon of cleavage fracture initiation in rock salt undergoing concurrent creep was studied experimentally using the Brazilian indirect tension test technique. The tensile creep and cleavage fracture behaviors were characterized for rock salt from the Waste Isolation Pilot Plant (WIPP) site. The Brazilian test consists of a compressive line load applied diametrically on a disk specimen to produce a region of tensile stress in the center of the disk. The damage processes were documented using video photography. The experimental results were analyzed in terms of a wing-crack fracture model and an independently developed, coupled time-dependent, mechanism-based constitutive model whose parameters were obtained from triaxial compression creep tests. Analytical results indicate that coupling between creep and cleavage fracture in WIPP salt results in a fracture behavior that exhibits time-dependent characteristics and obeys a failure criterion involving a combination of stress difference and tensile stress. Implications of creep-induced cleavage fracture to the integrity of WIPP structures are discussed.
Issue Section:
Technical Papers
Topics:
Creep,
Fracture (Materials),
Tension,
Disks,
Rocks,
Stress,
Compression,
Constitutive equations,
Damage,
Failure,
Photography,
Wings
1.
Ashby
M. F.
1983
, “Mechanisms of Deformation and Fracture
,” Advances in Applied Mechanics
, Vol. 23
, pp. 117
–177
.2.
Ashby
M. F.
Hallam
S. D.
1986
, “The Failure of Brittle Solids Containing Small Cracks Under Compressive Stress States
,” Acta Metallurgica
, Vol. 34
, pp. 497
–510
.3.
Chan
K. S.
Bodner
S. R.
Fossum
A. F.
Munson
D. E.
1992
, “A Constitutive Model for Inelastic Flow and Damage Evolution in Solids Under Triaxial Compression
,” Mechanics of Materials
, Vol. 14
, pp. 1
–14
.4.
Chan
K. S.
Brodsky
N. S.
Fossum
A. F.
Bodner
S. R.
Munson
D. E.
1994
, “Damage-Induced Nonassociated Inelastic Flow in Rock Salt
,” International Journal of Plasticits
, Vol. 10
, No. 6
, pp. 623
–642
.5.
Chan, K. S., DeVries, K. L., Bodner, S. R., Fossum, A. F., and Munson, D. E., 1995, “A Damage Mechanics Approach to Life Prediction for a Salt Structure,” Computational Mechanics ’95, S. N. Atluri, G. Yagawa, and T. A. Cruse, eds., Springer-Verlag, Berlin, Vol. 1, pp. 1140–1145.
6.
Chan
K. S.
Munson
D. E.
Bodner
S. R.
Fossum
A. F.
1996
, “Cleavage and Creep Fracture of Rock Salt
,” Acta Materialic
, Vol. 44
, pp. 3553
–3565
.7.
Chan
K. S.
Bodner
S. R. M.
Fossum
A. F.
Munson
D. E.
1997
a, “A Damage Mechanics Treatment of Creep Failure in Rock Salt
,” International Journal of Damage Mechanics
, Vol. 6
, pp. 121
–152
.8.
Chan, K. S., Munson, D. E., Fossum, A. F., and Bodner, S. R., 1997b, “A Constitutive Model for Representing Coupled Creep, Fracture, and Healing in Rock Salt,” Proceedings of the Fourth Conference on the Mechanical Behavior of Salt, E´cole Polytechnique de Montre´al, University of Montre´al, June 17–18, 1996, Karl Distributors, Rockport, MA, pp. 221–234.(in press).
9.
Costin, L. S., and Wawersik, W. R., 1980, Creep Healing of Fracture in Rock Salt, SAND-80–0392. Sandia National Laboratories, Albuquerque, NM.
10.
Fossum, A. F., Callahan, G. D., Van Sambeek, L. L., and Senseny, P., 1988, “How Should One-Dimensional Laboratory Equations Be Cast Into Three-Dimensional Form?” Key Questions in Rock Mechanics, Proceedings of the 29th Symposium on Rock Mechanics, Minneapolis, MN, June 13–15. 1988, P. A. Cundall, R. L. Sterling, and A. M. Starfield, eds., A. A. Balkema, Brookfield, VT, pp. 35–41.
11.
Fossum, A. F., Brodsky, N. S., Chan, K. S., and Munson, D. E., 1993, “Experimental Evaluation of a Constitutive Model For Inelastic Flow and Damage Evolution in Solids Subjected to Triaxial Compression,” presented at the 34th U.S. Rock Mechanics Symposium, International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, Vol. 30, pp. 1341–1344.
12.
Frocht, M. M., 1948, Photoelasticity, Vol. II, Wiley, New York, pp. 121–129.
13.
Gandhi
C.
Ashby
M. F.
1979
, “Fracture-Mechanism Maps for Materials which Cleave: F.C.C., B.C.C., and H.C.P. Metals and Ceramics
,” Acta Metallurgica
, Vol. 27
, pp. 1565
–1602
.14.
Griffith
A. A.
1921
, “The Phenomena of Rupture and Flow in Solids
,” Philosophical Transactions, Royal Society of London
, Vol. 221A
, pp. 163
–197
.15.
Horii
H.
Nemat-Nasser
S.
1985
, “Compression-Induced Microcrack Growth in Brittle Solids: Axial Splitting and Shear Failure
,” Journal of Geophysical Research
, Vol. 90
, pp. 3105
–3125
.16.
Hunsche, U. E., 1993, “Failure Behaviour of Rock Salt Around Underground Cavities,” Proceedings of the 7th Symposium on Salt, Vol. I, Elsevier Science Pub., New York, pp. 59–65.
17.
Kachanov
L. M.
1958
, “On Creep Rupture Time
,” Otdelenie Tekhnicheskikh Nauk
, Izvestiya Akademii Nauk SSSR, Vol. 8
, pp. 26
–31
.(in Russian).18.
Leckie
F. A.
Hayhurst
D.
1977
, “Constitutive Equations for Creep Rupture
,” Acta Metallurgica
, Vol. 25
, No. 9
, pp. 1059
–1070
.19.
Munson, D. E., 1979, Preliminary Deformation-Mechanism Map for Salt (with Application to WIPP), SAND79–0076, Sandia National Laboratories, Albuquerque, NM.
20.
Munson, D. E., and Dawson, P. R., 1984, “Salt Constitutive Modeling using Mechanism Maps,” Proceedings of the First Conference on the Mechanical Behavior of Salt, Karl Distributors, Rockport, MA, pp. 717–737.
21.
Nemat-Nasser
S.
Horii
H.
1982
, “Compression-Induced Nonplanar Crack Extension with Application to Splitting, Exfoliation, and Rockburst
,” Journal of Geophysical Research
, Vol. 87
, pp. 6805
–6821
.22.
Shaw
M. C.
Braiden
P. M.
DeSalvo
G. J.
1975
, “The Disk Test for Brittle Materials
,” ASME Journal of Engineering for Industry
, Vol. 97
, No. 1
, pp. 77
–87
.23.
Tada, H., Paris, P., and Irwin, G., 1973, “The Stress Analysis of Cracks Handbook,” Del Research, Hellertown, PA.
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