International Journal for Numerical and Analytical Methods in Geomechanics,
Год журнала:
2024,
Номер
unknown
Опубликована: Сен. 19, 2024
ABSTRACT
We
present
a
double‐phase–field
framework
for
tensile
fracturing
processes
in
transversely
isotropic
rocks.
Two
distinct
phase‐field
variables
are
introduced
to
represent
smeared
approximations
of
fractures
along
the
weak
bedding
planes
and
through
anisotropic
rock
matrix,
respectively.
Driving
forces
that
control
fracture
propagation
constructed
as
stress‐based
formula
with
recently
developed
failure
criterion
distinguishes
two
modes
For
numerical
implementation,
we
adopt
staggered
integration
scheme
decouple
governing
equations
so
displacement
field
can
be
updated
sequence
given
loading
step.
The
finite
element
formulation
proposed
is
detail
this
paper
implemented
an
in‐house
code.
implementation
then
validated
by
reproducing
uniaxial
tension
test
results
Lyons
sandstone.
After
that,
conduct
simulations
on
pre‐notched
square
plate
loaded
demonstrate
features
framework.
Finally,
three‐point
bending
tests
Pengshui
shale
show
model
reproduce
force–displacement
curves
patterns
specimens
different
plane
orientations
observed
laboratory
experiments.
Journal of the Mechanics and Physics of Solids,
Год журнала:
2023,
Номер
173, С. 105228 - 105228
Опубликована: Фев. 2, 2023
We
present
a
new
phase-field
formulation
for
the
formation
and
propagation
of
compaction
band
in
high-porosity
rocks.
Novel
features
proposed
include
(a)
effects
inertia
on
rate
development
bands,
(b)
degradation
mechanisms
tension,
compression,
shear
appropriate
dynamic
strain
localization
problems
where
disturbances
propagate
time
wave-like
fashion
to
induce
micro-cracking,
grain
crushing,
frictional
rearrangement
rock.
also
robust
numerical
technique
handle
spatiotemporal
evolution
band.
validate
model
by
simulating
benchmark
problem
involving
V-shape
notched
cylindrical
specimen
Bentheim
sandstone
tested
conventional
triaxial
compression.
The
is
shown
reproduce
different
geometric
styles
deformation
that
pure
compaction,
shear-enhanced
combination
mechanism
consists
straight
primary
surrounded
secondary
chevron
bands.
International Journal for Numerical and Analytical Methods in Geomechanics,
Год журнала:
2022,
Номер
46(16), С. 2965 - 2987
Опубликована: Авг. 11, 2022
Abstract
Compaction
bands
are
tabular
regions
of
localized
compressive
deformation
with
little
or
no
shear
offset.
Often
observed
in
high‐porosity
rocks,
they
can
be
classified
into
several
subtypes
based
on
their
pattern
and
orientation
respect
to
the
maximum
principal
stress.
The
combined
effects
material
properties
loading
conditions
type
compaction
that
develop
not
fully
understood,
realistic
simulations
formation
always
successful.
In
this
study,
a
phase‐field
approach
for
capturing
propagation
is
proposed.
fracture
energy
utilized
classic
formulations
interpreted
driven
by
grain
crushing
herein
characterized
breakage
mechanics
theory.
A
new
decomposition
free
function
introduced
which
stored
plastic
compactive
flow
drives
crushing.
Depending
value
release
rate,
model
predicts
different
styles
remarkably
consistent
those
field.
Numerical
demonstrate
role
confining
pressure,
plasticity,
critical
predicted
bands.
International Journal for Numerical and Analytical Methods in Geomechanics,
Год журнала:
2022,
Номер
46(8), С. 1383 - 1408
Опубликована: Фев. 27, 2022
Abstract
The
last
several
decades
have
seen
a
surge
of
papers
dealing
with
analytical
and
semi‐analytical
solutions
to
the
problem
one‐dimensional
consolidation
soils.
But
rarely
has
any
these
contributions
focused
on
time
scales
arising
from
combined
primary
secondary
compression.
Primary
compression
always
been
attributed
dissipation
excess
pore
pressure
as
fluid
is
expelled
soil
skeleton
drainage
boundaries.
However,
there
schools
thought
when
it
comes
process
governing
In
this
paper,
we
attribute
following
processes
occurring
either
individually
or
in
combination:
(a)
rate‐dependent
(viscoplastic)
constitutive
response
skeleton;
(b)
existence
scale
system
that
expels
smaller‐scale
pores
larger‐scale
pores;
(c)
delayed
due
creep
Bjerrum's
concept
consolidation.
Contributions
present
work
include
closed‐form
soils
one
dimension,
well
quantitative
analysis
involved
such
coupled
hydromechanical
processes.
