HR: 1330h
AN: T42A-0279    [PDF]
TI: Modeling constitutive behavior and compaction localization for high porosity sandstone
AU: * Grueschow, E R
EM: e-grueschow@northwestern.edu
AF: Northwestern University, Mechanical Engineering 2145 Sheridan Rd, Evanston, IL 60208 United States
AU: Rudnicki, J W
EM: jwrudn@northwestern.edu
AF: Northwestern University, Mechanical Engineering 2145 Sheridan Rd, Evanston, IL 60208 United States
AB: The yield behavior of Castlegate sandstone (28 percent porosity) has been investigated with a variety of compressive loading paths. The initial yield surface was modeled as an ellipse quadrant with an intercept of 190 MPa along the pressure axis and 10 MPa along the differential stress axis. Unload loops during testing were used to model the decay of the shear modulus. Plastic strain behavior was fit using a separate hardening parameter along each axis and non-associated flow. Contrary to experiments, shear localization was predicted to precede compaction localization due to the small aspect ratio of the yield surface. With an aspect ratio nearer to unity, as suggested for a variety of sandstones by recent results from TF Wong et al, the model may predict compaction localization.
DE: 5120 Plasticity, diffusion, and creep
DE: 5199 General or miscellaneous
DE: 8020 Mechanics
SC: Tectonophysics [T]
MN: 2003 Fall Meeting