Applied Mathematics and Mechanics,
Journal Year:
2024,
Volume and Issue:
45(11), P. 1929 - 1948
Published: Oct. 17, 2024
Abstract
The
spatiotemporally-nonlocal
phenomena
in
heat
conduction
become
significant
but
challenging
for
metamaterials
with
artificial
microstructures.
However,
the
microstructure-dependent
are
captured
under
hypothesis
of
spatiotemporally
local
equilibrium.
To
capture
phenomena,
a
generalized
nonlocal
irreversible
thermodynamics
is
proposed
by
removing
both
temporally-local
and
spatially-local
equilibrium
hypotheses
from
classical
thermodynamics.
has
intrinsic
length
time
parameters
thus
can
provide
basis
law
conduction.
remove
hypothesis,
entropy
assumed
to
depend
not
only
on
internal
energy
also
its
first-order
high-order
derivatives.
spatially
flux
field
dissipation
function
relate
force
at
reference
point
neighboring
points.
With
developed
theoretical
framework,
thermodynamics-consistent
models
then
be
transfer
problems.
Two
examples
provided
illustrate
applications
steady-state
transient
Continuum Mechanics and Thermodynamics,
Journal Year:
2024,
Volume and Issue:
37(1)
Published: Dec. 15, 2024
Abstract
At
the
microscale
and
nanoscale,
materials
exhibit
size-dependent
behaviors
that
classical
models
cannot
capture.
This
analysis
introduces
a
higher-order
thermoelastic
heat
conduction
model,
incorporating
spatial
temporal
nonlocal
effects
in
micropolar
visco-thermoelastic
medium
subjected
to
laser
pulse
flux.
The
two-phase
delay
featuring
derivatives,
captures
complex
interactions
among
mechanical,
thermal,
viscous
properties
where
size
are
significant.
By
including
phase
lag,
model
effectively
addresses
non-Fourier
short-duration
scenarios.
It
accurately
predicts
temperature
distribution,
stress
response,
microrotation
nanoscale
materials.
study
visually
represents
how
factors
such
as
micropolarity,
effects,
delay,
index,
viscosity
influence
mechanical
behavior
of
half-space
structure.
numerical
results
highlight
importance
phenomena
nanostructures,
revealing
deviations
from
predictions
due
interactions.
Overall,
proposed
spatiotemporal
homogenization
serves
valuable
tool
for
analyzing
thermal
characteristics
nanomaterials.
Mechanics of Advanced Materials and Structures,
Journal Year:
2025,
Volume and Issue:
unknown, P. 1 - 18
Published: Jan. 2, 2025
The
classical
multiscale
homogenization
methods
can
only
take
into
account
the
pure
microstructural
effect,
resulting
in
inability
to
accurately
capture
nonlocal
interactions
emerged
from
underlying
microstructures
of
metamaterial
structures.
This
paper
explores
interplay
mechanism
that
artificial
and
develops
a
well-posed
microstructure-emerged
method
capable
capturing
nonlocality
is
strictly
related
its
extrinsic
intrinsic
length
scales.
First,
we
propose
novel
concentrated
element
model
accounts
for
both
effect
interaction
describe
static
response
trusses.
not
considers
but
also
further
interaction,
thus
providing
more
comprehensive
description
Then,
based
on
model,
developed
trusses
with
an
accuracy
comparable
high-fidelity
numerical
methods.
Since
well-posed,
closed-form
solution
displacement
truss
obtained.
High-fidelity
finite
simulations
show
effective
moduli
different
have
significant
effects,
especially
high
porosity.
Results
indicate
provides
robust
accurate
representation
truss,
significantly
outperforming
consider
effects.
International journal of mechanical system dynamics,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Dec. 9, 2024
Abstract
This
paper
aims
to
analyse
the
free
vibrations
of
doubly
curved
imperfect
shear
deformable
functionally
graded
material
microshells
using
a
five‐parameter
model.
Porosity
is
modeled
via
modified
power‐law
rule
by
logarithmic‐uneven
variation
along
thickness.
Coupled
axial,
transverse,
and
rotational
motion
equations
for
general
microsystems
are
obtained
virtual
work/energy
Hamilton's
principle
first‐order
theory
including
small
size
dependence.
The
modal
decomposition
method
then
used
obtain
solution
different
geometries
microshells:
spherical,
elliptical,
hyperbolic,
cylindrical.
A
detailed
study
on
influence
gradation
porosity,
small‐length
scale
coefficient,
geometrical
parameters
frequency
characteristics
microsystem
conducted
shell
geometries.
