Computational modeling of the transition from damage to fracture in intrinsically anisotropic porous media

Jin, Wencheng

Title:

Computational modeling of the transition from damage to fracture in intrinsically anisotropic porous media

dc.contributor.advisor	Arson, Chloé
dc.contributor.author	Jin, Wencheng
dc.contributor.committeeMember	Borja, Ronaldo
dc.contributor.committeeMember	Frost, David
dc.contributor.committeeMember	Neu, Richard
dc.contributor.committeeMember	Paulino, Glaucio
dc.contributor.committeeMember	White, Joshua
dc.contributor.department	Civil and Environmental Engineering
dc.date.accessioned	2019-01-16T17:21:33Z
dc.date.available	2019-01-16T17:21:33Z
dc.date.created	2018-12
dc.date.issued	2018-08-08
dc.date.submitted	December 2018
dc.date.updated	2019-01-16T17:21:33Z
dc.description.abstract	The initiation and propagation of discontinuities in brittle materials is of great interest to engineers, at several scales. Discontinuities can be detrimental for structures (borehole for nuclear waste disposal, cavity for storage, tunnel for transportation) but discontinuities are necessary to extract energy (hydraulic fracturing for oil, gas and geothermal resources). A number of numerical tools are available to model fracture propagation in brittle solids. However, the fundamental inception mechanisms at the micro-scale are not fully understood. Therefore, the goal of this doctoral research work is to understand the processes that govern the initiation and propagation of micro-cracks in mixed mode in crystalline and porous media, and to predict the transition from diffused micro-crack distribution to discrete macro-fracture. We first developed two constitutive laws that couple micro-mechanics and thermodynamics principles. Phenomena observed at the scale of a Representative Elementary Volume (REV), such as nonlinear behavior, induced anisotropy and unilateral effects, are captured by modeling microstructure evolution, e.g., mixed mode propagation for open cracks and secondary wing crack development for closed cracks. Dilute homogenization is used to connect the scale of the microstructure to that of the REV. The resulting nonlocal anisotropic damage model is coupled with a cohesive zone model. The transition point from continuum damage to discrete fracture is rigorous calibrated, so as to ensure energy conservation at the scale of the entire fractured domain. We further extended the framework of damage-fracture transition to simulate multiscale fracture propagation driven by fluid injection in transversely isotropic porous media. After deriving the weak formulation and discretizing the model with the extended finite element method, we investigated the influence of material and stress anisotropy on hydraulic fracture paths. Advanced numerical methods presented in this thesis shed light on the mechanical behavior of brittle materials at several scales, and provide tools to solve practical engineering problems.
dc.description.degree	Ph.D.
dc.format.mimetype	application/pdf
dc.identifier.uri	http://hdl.handle.net/1853/60723
dc.language.iso	en_US
dc.publisher	Georgia Institute of Technology
dc.subject	Continuum damage
dc.subject	Constitutive law
dc.subject	Wing crack
dc.subject	Micromechanics
dc.subject	Multiscale fracture propagation
dc.subject	Hydraulic fracturing
dc.subject	Cohesive zone
dc.subject	XFEM
dc.title	Computational modeling of the transition from damage to fracture in intrinsically anisotropic porous media
dc.type	Text
dc.type.genre	Dissertation
dspace.entity.type	Publication
local.contributor.advisor	Arson, Chloé
local.contributor.corporatename	School of Civil and Environmental Engineering
local.contributor.corporatename	College of Engineering
relation.isAdvisorOfPublication	ce5325f0-830f-4636-bc90-7527fd99005b
relation.isOrgUnitOfPublication	88639fad-d3ae-4867-9e7a-7c9e6d2ecc7c
relation.isOrgUnitOfPublication	7c022d60-21d5-497c-b552-95e489a06569
thesis.degree.level	Doctoral