Frontiers in Materials,
Journal Year:
2022,
Volume and Issue:
9
Published: June 16, 2022
Accurate
simulation
of
walking
load
is
great
significance
in
conducting
human-induced
vibration
analyses.
However,
accurate
pedestrian
data
obtained
from
long-span
footbridges
scarce
and
reliability
depends
on
the
sensor
used
for
measurement.
In
current
work,
Yanluo
Footbridge
with
102
m
span
was
adopted
as
test
site
Xnode
high-precision
acceleration
wireless
applied
measurements.
An
experimental
investigation
performed
loads
according
to
bipedal
force
model.
studies,
single-person
multi-person
tests
were
at
measure
corresponding
stride
frequency
dynamic
factor.
The
time-histories
pedestrians
accurately
recorded
using
three-axis
Xnode.
Furthermore,
equation
factor
derived
by
analyzing
power
spectra
design
models
crowd
developed
based
a
number
data.
Time
histories
showed
regular
periodic
changes
increased
increasing
frequency.
Using
model
this
reliable
structure
response
analysis
can
be
obtained.
Mechanics of Advanced Materials and Structures,
Journal Year:
2022,
Volume and Issue:
30(16), P. 3385 - 3405
Published: May 13, 2022
Smart
materials
and
structures
at
the
nanoscale
represent
main
components
in
manufacturing
plan
for
nano-electromechanical
systems.
In
this
research
study,
an
unconventional
shell
model
based
upon
nonlocal
couple
stress
(NCS)
continuum
mechanics
accommodating
both
softening
stiffening
features
of
size
dependency
is
formulated
to
analyze
buckling
mode
transition
phenomenon
nonlinear
stability
characteristics
functionally
graded
(FG)
piezoelectric
nanoshells
subjected
thermo-electromechanical
load.
To
accomplish
objective,
efficient
numerical
strategy
moving
Kriging
meshfree
(MKM)
technique
employed
via
different
nodal
distribution
schemes,
including
Chebyshev,
regular
uniform
irregular
ones.
The
established
NCS-based
has
capability
incorporate
as
well
satisfying
function
property
Kronecker
delta
imposing
essential
boundary
conditions
with
no
use
predefined
mesh
directly
associated
nodes.
It
also
demonstrated
that
by
changing
sign
electric
actuation
from
negative
positive,
character
nonlocality
strengthening
become
a
bit
more
significant.
Furthermore,
roles
tensors
are
prominent
value
second
bifurcation
point
comparison
first
one.
Facta Universitatis Series Mechanical Engineering,
Journal Year:
2023,
Volume and Issue:
21(1), P. 031 - 031
Published: April 10, 2023
In
this
paper,
free
vibration,
modal
and
stress
state
analyses
of
honeycomb
sandwich
structures
with
different
boundary
conditions
was
investigated
major
factors
affecting
the
frequencies
stiffness
due
to
material
or
parameter
changes
were
determined.
The
representative
volume
element
(RVE)
method
used
in
work
analytically
numerically
validated
by
comparing
obtained
results
those
available
literature.
Firstly,
unit
cell
capture
entire
effects
parameters
on
vibration
structure
ANSYS.
This
study
analyzed
natural
core
materials
combination.
foil
thickness,
conditions,
selection,
density
presence
crack
taken
into
consideration
examined.
proposed
had
an
inbuilt
shaped
reinforcement
for
effective
resonance,
fatigue
deformation
resistance
at
much
higher
frequency.
Physica Scripta,
Journal Year:
2022,
Volume and Issue:
97(8), P. 085216 - 085216
Published: July 15, 2022
Abstract
In
this
paper,
nonlinear
dynamic
snap-through
buckling
and
vibration
behavior
of
the
thermally
post-buckled
functionally
graded
(FG)
porous
nanobeams
subjected
to
static
sudden
mechanical
loads
are
investigated
utilizing
nonlocal
elasticity
theory.
The
physical
properties
nanobeam
considered
be
functions
temperature
based
on
Touloukian
model.
addition,
describe
FG
materials,
two
different
patterns
porosity
distribution
adopted
using
trigonometric
through
thickness
nanobeam.
equations
motion
in
conjunction
with
von-Kármán
assumption
established
framework
Hamilton’s
principle.
By
employing
Chebyshev-Ritz
procedure,
discretized
for
three
types
edge
supports.
Following
that,
cylindrical
arc-length
technique
is
employed
assess
vibrational
responses
during
buckling.
To
evaluate
under
a
load,
Newmark
time
integration
scheme
together
Newton-Raphson
iterative
method
utilized.
Next,
by
means
Budiansky-Roth
criterion
phase-plane
approach,
identified.
After
validating
developed
mathematical
model,
comprehensive
investigation
carried
out
determine
role
various
geometrical
parameters
characteristics
nanobeams.
Physica Scripta,
Journal Year:
2023,
Volume and Issue:
98(3), P. 035710 - 035710
Published: Feb. 2, 2023
Abstract
In
present
research
exploration,
the
nonlinear
dynamic
stability
characteristics
of
axially
compressed
nanocomposite
plates
at
micro/nano-scale
reinforced
with
randomly
oriented
carbon
nanotubes
(CNTs)
are
investigated
within
both
prebuckling
and
postbuckling
regimes.
To
accomplish
this
examination,
nonlocal
couple
stress
(NCS)
continuum
elasticity
is
incorporated
to
a
quasi-3D
plate
theory
which
separates
deformation
bending
shear
parts
considering
simultaneously
transverse
normal
displacements.
addition,
two-parameter
homogenization
scheme
utilized
obtain
effective
characters
CNT-reinforced
nanocomposites.
The
NCS-based
differential
equations
motion
discretized
using
Kronecker
tensor
product
together
shifted
Chebyshev-Gauss-Lobatto
gridding
pattern.
Thereafter,
Galerkin
technique
pseudo
arc-length
continuation
method
employed
achieve
fRequency-load
frequency
ratio-deflection
curves
before
after
bifurcation
point.
It
deduced
that
for
heterogeneous
micro/nano-plate
in
most
CNTs
located
inside
clusters,
increasing
value
cluster
volume
fraction
leads
increase
bit
significance
softening
stiffing
related
tensors
phenomenon,
but
it
causes
decrease
them
critical
Opposite
patterns
phenomenon
predicted
agglomeration
outside
clusters.
Mechanics Based Design of Structures and Machines,
Journal Year:
2023,
Volume and Issue:
52(7), P. 3974 - 4008
Published: May 25, 2023
There
is
a
diverse
and
well-constructed
application
of
energy
harvesting
systems
due
to
their
innovate
technology
provide
the
necessary
power
for
low-energy
electronics.
In
this
regard,
prime
objective
current
study
analyze
size-dependent
nonlinear
dynamic
performance
piezoelectric
beam-type
harvesters
at
nanoscale
subjected
time-dependent
mechanical
uniform
load.
A
laminated
structure
containing
an
agglomerated
nanocomposite
core
integrated
with
top
bottom
surface
layers
considered
bridge-type
harvesters.
To
take
size
dependency
into
account,
nonlocal
strain
gradient
continuum
elasticity
formulated
based
upon
quasi-3D
beam
theory
incorporating
both
features
effects.
Thereafter,
problem
then
solved
numerically
relevant
simply
supported
clamped
end
conditions
via
employing
meshless
collocation
technique.
Accordingly,
numerical
solving
procedure
established
without
any
background
meshes
as
well
eliminating
integration
singularity
by
using
proper
multiquadric
radial
basis
functions.
