This work introduces a unified mathematical framework to replicate both desiccation-induced and hydraulic fracturing in low-permeable unsaturated porous materials observed in experiments. The unsaturated porous medium is considered as a three-phase solid–liquid–gas effective medium of which each constituent occupies a fraction of the representative elementary volume. As such, an energy-minimization-based phase-field model (PFM) is formulated along with the Biot’s poroelasticity theory to replicate the sub-critical crack growth in the brittle regime. Unlike hydraulic fracturing where the excess pore liquid pressure plays an important role at the onset and propagation of cracks, desiccation cracks are mainly driven by deformation induced by water retention. Therefore, the wettability of the solid skeleton may affect the evolution of the capillary pressure (suction) and change the path-dependent responses of the porous media. This air–water–solid interaction may either hinder or enhance the cracking occurrence. This difference of capillary effect on crack growth during wetting and drying is replicated by introducing retention-sensitive degradation mechanisms in our phase field fracture approach. To replicate the hydraulic behaviors of the pore space inside the host matrix and that of the cracks, the path-dependent changes of the intrinsic permeability due to crack growth and porosity changes are introduced to model the flow conduit in open and closed cracks. Numerical examples of drying-induced and hydraulic fracturing demonstrate the capability of the proposed model to capture different fracture patterns, which qualitatively agrees with the fracture mechanisms of related experiments documented in the literature.
Heider, Yousef and Sun, WaiChing. "A phase field framework for capillary-induced fracture in unsaturated porous media: Drying-induced vs. hydraulic cracking." Computer Methods in Applied Mechanics and Engineering, vol. 359, no. C, Oct. 2019. https://doi.org/10.1016/j.cma.2019.112647
Heider, Yousef, & Sun, WaiChing (2019). A phase field framework for capillary-induced fracture in unsaturated porous media: Drying-induced vs. hydraulic cracking. Computer Methods in Applied Mechanics and Engineering, 359(C). https://doi.org/10.1016/j.cma.2019.112647
Heider, Yousef, and Sun, WaiChing, "A phase field framework for capillary-induced fracture in unsaturated porous media: Drying-induced vs. hydraulic cracking," Computer Methods in Applied Mechanics and Engineering 359, no. C (2019), https://doi.org/10.1016/j.cma.2019.112647
@article{osti_1801239,
author = {Heider, Yousef and Sun, WaiChing},
title = {A phase field framework for capillary-induced fracture in unsaturated porous media: Drying-induced vs. hydraulic cracking},
annote = {This work introduces a unified mathematical framework to replicate both desiccation-induced and hydraulic fracturing in low-permeable unsaturated porous materials observed in experiments. The unsaturated porous medium is considered as a three-phase solid–liquid–gas effective medium of which each constituent occupies a fraction of the representative elementary volume. As such, an energy-minimization-based phase-field model (PFM) is formulated along with the Biot’s poroelasticity theory to replicate the sub-critical crack growth in the brittle regime. Unlike hydraulic fracturing where the excess pore liquid pressure plays an important role at the onset and propagation of cracks, desiccation cracks are mainly driven by deformation induced by water retention. Therefore, the wettability of the solid skeleton may affect the evolution of the capillary pressure (suction) and change the path-dependent responses of the porous media. This air–water–solid interaction may either hinder or enhance the cracking occurrence. This difference of capillary effect on crack growth during wetting and drying is replicated by introducing retention-sensitive degradation mechanisms in our phase field fracture approach. To replicate the hydraulic behaviors of the pore space inside the host matrix and that of the cracks, the path-dependent changes of the intrinsic permeability due to crack growth and porosity changes are introduced to model the flow conduit in open and closed cracks. Numerical examples of drying-induced and hydraulic fracturing demonstrate the capability of the proposed model to capture different fracture patterns, which qualitatively agrees with the fracture mechanisms of related experiments documented in the literature.},
doi = {10.1016/j.cma.2019.112647},
url = {https://www.osti.gov/biblio/1801239},
journal = {Computer Methods in Applied Mechanics and Engineering},
issn = {ISSN 0045-7825},
number = {C},
volume = {359},
place = {United States},
publisher = {Elsevier},
year = {2019},
month = {10}}
National Science Foundation (NSF); US Air Force Office of Scientific Research (AFOSR); US Army Research Office (ARO); USDOE; USDOE Office of Nuclear Energy (NE)
Grant/Contract Number:
NE0008534
OSTI ID:
1801239
Alternate ID(s):
OSTI ID: 1580796
Journal Information:
Computer Methods in Applied Mechanics and Engineering, Journal Name: Computer Methods in Applied Mechanics and Engineering Journal Issue: C Vol. 359; ISSN 0045-7825