Browsing School of Civil and Environmental Engineering Publications and Presentations by Title
Now showing items 68-87 of 109
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Multi-Scale Fracture Creation and Network Generation During Hydraulic Fracturing
(Georgia Institute of Technology, 2013-06)Here we describe both a sequential, hierarchical multi-scale approach for designing scale-dependent constitutive models at different levels of refinement in the problem as well as an open-source, massively parallel software ... -
A Multiphase Analysis for Environmental Impact Assessment with Theta-Stock Finite Element Program
(Georgia Institute of Technology, 2010-03)In the THM modeling of multiphase medium, the coupling effects of skeleton, suction, and temperature have been integrated via the concept of state surfaces of void ratio and degree of saturation. Based on proposed formulation, ... -
Non-Local Micromechanical Anisotropic Damage Modeling Of Quasi-Brittle Materials: Formulation And Implementation
(Georgia Institute of Technology, 2017-06)A nonlocal anisotropic damage model is proposed for quasi-brittle materials, such as concrete and rock. The local anisotropic damage model is formulated by combining a free energy derived from micromechanics with ... -
Nonlocal enrichment of a micromechanical damage model with tensile softening: advantages and limitations
(Georgia Institute of Technology, 2017-09)Upon crack propagation, brittle geomaterials such as concrete and rock exhibit a nonlinear stress/strain behavior, damage induced stiffness anisotropy, loading path dependent strain softening and hardening, unilateral ... -
Numerical study of a thermo-hydro-mechanical damage model for unsaturated porous media
(Georgia Institute of Technology, 2010-05)The “THHMD” damage model presented in this article is dedicated to non-isothermal unsaturated porous media. The proposed frame is based on the use of independent state variables (net stress, suction and thermal stress). ... -
Numerical Study of Damage in Unsaturated Geological and Engineered Barriers
(Georgia Institute of Technology, 2011-04)The theoretical framework of a damage model dedicated to non-isothermal unsaturated porous media is presented. The damage variable is a second-order tensor, and the model is formulated in independent state variables. The ... -
Numerical study of the influence of fluid viscosity on wellbore spalling in drained fractured rock
(Georgia Institute of Technology, 2015-07)The objective of this work is to model the influence of shear stresses induced by viscous fluid flow on wellbore spalling. We simulated a drop of stress and pore pressure at the wall of a meter-scale borehole with a plane ... -
Numerical Study of Thermo-Mechanical Effects on the Viscous Damage Behavior of Rock Salt Caverns
(Georgia Institute of Technology, 2017-06)Underground cavities in rock salt have received increased attention for the storage of oil, gas, and compressed air energy. In this study, the transition between secondary and tertiary creep in salt is determined by a ... -
On damage modelling in unsaturated clay rocks
(Georgia Institute of Technology, 2008-10)The aim of this paper is to present the main problems encountered in the modelling of damage in an unsaturated quasi-brittle rock mass. Micromechanical damage models are based on a physical definition of damage, related ... -
On The Definition Of Damage In Time-Dependent Healing Models For Salt Rock
(Georgia Institute of Technology, 2012-07)his research is motivated by the increasing need for geostorage facilities such as nuclear waste disposals, high-pressure gas reservoirs and carbon dioxide sequestration systems. Salt rock has favourable creep properties, ... -
Prediction of viscous cracking and cyclic fatigue of salt polycrystals using a joint-enriched Finite Element Model
(Georgia Institute of Technology, 2016-09)We present a new Joint-enriched Finite Element Method (JFEM) to predict viscous damage and fatigue in halite polycrystals in 2D. Different visco-plastic finite elements are used to represent grains of different orientations, ... -
Probabilistic Calibration of a Damage Rock Mechanics Model
(Georgia Institute of Technology, 2014-01)Current practice in the calibration of damage models requires downscaling the effects of experimental observations from macro/meso to micro. This process introduces uncertainty that is seldom quantified to reflect the ... -
Probabilistic Optimization of a Continuum Mechanics Model to Predict Differential Stress-Induced Damage in Claystone
(Georgia Institute of Technology, 2014-06)Phenomenological modeling of anisotropic damage in rock raises many fundamental thermodynamic and mechanical issues. In this paper, the maximum likelihood method is used to analyze the performance of the Differential Stress ... -
Retention and Permeability Properties of Damaged Porous Rocks
(Georgia Institute of Technology, 2013-10)The objective of this research work is to model the influence of deformation and damage on the permeability and retention properties of cracked porous media. This is achieved thanks to the introduction of microscale ... -
The Risks of Hydraulic Fracturing and the Responsibilities of Engineers
(2017-03)One third of U.S. natural gas is extracted by injecting fluid at high pressure into shale formations, a process associated with a number of possible hazards and risks that have become the subject of intense public controversy. ... -
Rock Damage and Healing Mechanics
(Georgia Institute of Technology, 2014-05-15) -
Rock Stiffness and Permeability During Crack Opening and Closure: A Planar Transverse Isotropic (PTI) Model Using Pore Size Distributions (PSD)
(Georgia Institute of Technology, 2013-07)A micro-macro model is proposed to study opening and closure of parallel crack planes in a porous rock. Pore Size Distributions (PSDs) of natural pores and cracks are updated with volumetric fractions, defined as distinct ... -
Seismic site effects by an optimized 2D BE/FE method I. Theory, numerical optimization and application to topographical irregularities
(Georgia Institute of Technology, 2007-10)This paper deals with the evaluation of seismic site effects due to the local topographical and geotechnical characteristics. The amplification of surface motions is calculated by a numerical method combining finite elements ... -
Seismic site effects by an optimized 2D BE/FE method. II. Quantification of site effects in two-dimensional sedimentary valleys
(Georgia Institute of Technology, 2007-10)This paper deals with the evaluation of seismic site effects due to the local topographical and geotechnical characteristics. The amplification of surface motions is calculated by a numerical method combining finite elements ... -
Self-consistent micromechanical approach for damage accommodation in rock-like polycrystalline materials
(Georgia Institute of Technology, 2017)In quasi-brittle polycrystalline materials, damage by cracking or cleavage dominates plastic and viscous deformation. This paper proposes a micromechanical model for rock-like materials, incorporating the elastic-damage ...
