Constitutive model describing dilatancy and cracking in brittle rocks

Journal Article · Sat Apr 10 04:00:00 EST 1982 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JB087iB04p02985· OSTI ID:6807443

Moss, W C; Gupta, Y M

A micromechanical constitutive model, based on the responses of sliding cracks and elliptic cracks, is used to simulate the inelastic deformation of brittle rock. In addition to the usual incremental equations, the model has the following features: (1) activation equation that include the effects of friction and relate the far-field stresses of sliding and elliptic crack openings and lengths, (2) a stress intensity analysis of the sliding cracks that determines how much the cracks may grow, and (3) expressions for the crack strains that are constructed directly from the amount of crack sliding, opening, growth and the number of sliding and elliptic cracks in a given region. Numerical simulations of uniaxial and triaxial loading experiments on westerly granite were compared with experimental data to determine the validity of the constitutive model. These comparisons show that most of the uniaxial stress data and the loading portion of the triaxial data can be simulated quantitatively. The unloading portion of the triaxial data cannot be simulated properly, suggesting that a nonfrictional mechanism, not included in our model, may dominate the response in this region.

• Research Organization: SRI International, Menlo Park, California 94025
• OSTI ID: 6807443
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 87:B4; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580300* -- Mineralogy
Petrology
& Rock Mechanics-- (-1989)
CRACK PROPAGATION
CRACKS
EXPANSION
FRACTURE MECHANICS
FRICTION
GRANITES
IGNEOUS ROCKS
MECHANICS
NUMERICAL SOLUTION
PLUTONIC ROCKS
ROCK MECHANICS
ROCKS
STRESS INTENSITY FACTORS
THERMAL EXPANSION