Modeling fracture in cemented granular material

Conference · Sat Oct 01 00:00:00 EDT 1994

OSTI ID:10109398

Trent, B. C.; Margolin, L. G.

We have conducted an extensive study to determine the underlying physical processes that govern inelastic behavior in brittle geologic materials. The distinct element method has been used to perform many different numerical experiments to help understand how permanent macroscopic deformations can be characterized in terms of microscopic parameters, such as fracture of binding material and topology of granular matrix. In particular, we have constructed a distinct element model of a cemented granular material which accounts for the elastic forces due to bonding between pairs of spherical particles, and which allows for the possibility of anisotropic damage to the bonds due to the growth of small brittle cracks within the bonds. We then develop a general constitutive theory that estimates the effective elastic moduli of a cemented granular material by applying statistical mechanical averaging to a purely micromechanical model. In this paper, we use the numerical model to validate the predictions of the theory for various prescribed patterns of damage. Specifically, we impose several anisotropic patterns of damage on the bonds of a randomly generated assembly of particles. We then do numerical experiments, sending both p-waves and s-waves through samples and measuring the wave velocities. Predictions of theory for these velocities agree well with results of the numerical model for a variety of damage patterns. We discuss the implications of our theory, as well as potential applications.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 10109398
• Report Number(s): LA-UR--93-4416; CONF-941040--1; ON: DE94004560
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000
665000
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
DAMAGE
ELASTICITY
FRACTURES
GEOLOGIC FRACTURES
GEOLOGIC STRATA
GEOSCIENCES
GRANULAR MATERIALS
MATHEMATICAL MODELS
NUMERICAL SOLUTION
P WAVES
PARTICLES
PHYSICS OF CONDENSED MATTER
S WAVES
SEISMIC WAVES
STATISTICAL MECHANICS