In
this
research,
the
free
vibration
analysis
is
investigated
for
a
sandwich
conical
shell
with
two
nanocomposite
face
layers
and
either
hexagonal
honeycomb
(HH)
or
re-entrant
(RH)
core
oriented
in
an
arbitrary
direction.
Both
HH
RH
cores
are
orthotropic
structures,
but
auxetic
structure
non-auxetic
one.
The
fabricated
of
polymeric
matrix
strengthened
uniformly
distributed
agglomerated
carbon
nanotubes
(CNTs)
graphene
nanoplatelets
(GNPs).
modeled
via
Murakami’s
zig-zag
theory,
governing
equations
boundary
conditions
derived
through
Hamilton’s
principle.
influences
various
parameters
on
natural
frequencies
including
orientation,
wall
thickness,
inclined
angle
cells
core,
thickness
mass
fraction
type
nanofibers,
agglomeration
intensity,
conditions.
It
concluded
that
each
vibrational
mode,
there
optimum
values
orientation
which
result
highest
frequency.
Mechanics of Advanced Materials and Structures,
Journal Year:
2024,
Volume and Issue:
unknown, P. 1 - 24
Published: Dec. 10, 2024
In
the
field
of
medical
technology,
specialized
equipment
utilizes
tubular
metastructures
with
a
negative
Poisson's
ratio
in
vascular
stents
to
reduce
risk
embolism.
The
deliberate
incorporation
auxetic
structures
into
stent
design
offers
several
benefits
over
traditional
stents.
This
study
examines
nonlinear
instability
and
bending
responses
reentrant
perfect
imperfect
3D-printed
metastructures.
First,
governing
equations
for
tube
geometric
imperfections
under
transverse
axial
mechanical
loads
are
derived
using
von-Kármán
assumption
Timoshenko
theory.
Then,
principle
virtual
displacement.
physical
characteristics
structure
Malek-Gibson
relations,
while
tensile
tests
digital
image
correlation
(DIC)
used
determine
properties
polylactic
acid
(PLA).
Scanning
electron
microscopy
(SEM)
images
help
investigate
variations
modulus
elasticity
ultimate
strength
dogbone
specimens,
Ritz
method
Chebyshev
polynomials
is
employed
discretize
equations.
Second,
two
numerical
algorithms
analyze
static
behavior
metatube
within
framework.
validation
conducted
representative
volume
element
(RVE)
unit
cell
based
on
literature
finite
software
Abaqus.
Following
mathematical
model,
an
extensive
investigation
assess
how
differing
parameters
impact
analysis
tube.
Vibration,
Journal Year:
2025,
Volume and Issue:
8(1), P. 2 - 2
Published: Jan. 13, 2025
Different
additive
manufacturing
modalities
enable
the
production
of
multi-material
components
which
can
be
used
in
a
wide
range
industrial
applications.
The
prediction
mechanical
properties
these
via
finite
element
modelling
rather
than
through
testing
is
critical
terms
cost
and
time.
However,
due
to
higher
computational
time
spent
on
lattice
structures,
different
methods
have
been
investigated
accurately
predict
properties.
For
this
purpose,
study
proposes
use
homogenization
method
two
most
common
types
lattices:
honeycomb
re-entrant
auxetics.
Modal
analyses
were
performed,
first
six
mode
shapes
extracted
from
explicit
implicit
models.
results
compared
natural
frequencies.
showed
that
successfully
applied
auxetic
lattices
without
compromising
accuracy.
It
was
shown
models
frequencies
with
an
error
less
6.5%
when
all
for
both
lattices.
Assurance
Criteria,
indication
degree
similarity
between
models,
found
0.996,
indicating
very
high
similarity.
