Buildings,
Год журнала:
2024,
Номер
14(9), С. 2591 - 2591
Опубликована: Авг. 23, 2024
Rayleigh
waves
are
vertically
elliptical
surface
traveling
along
the
ground
surface,
which
have
been
demonstrated
to
pose
potential
damage
buildings.
However,
traditional
seismic
barriers
limitations
of
high-frequency
narrow
bandgap
or
larger
volume,
constraints
on
application
in
practical
infrastructures.
Thus,
a
new
type
metamaterial
needs
be
further
investigated
generate
wide
low-frequency
bandgaps.
Firstly,
resonator
with
three-vibrator
is
proposed
effectively
attenuate
waves.
The
attenuation
characteristics
through
theoretical
and
finite
element
methods,
respectively.
formulas
established
based
local
resonance
mass-spring
theories,
can
Subsequently,
frequency
bandgaps
calculated
by
software
COMSOL5.6
model
Floquet–Bloch
theory
ultra-low-frequency
4.68–22.01
Hz.
Finally,
transmission
spectrum
time
history
analysis
used
analyze
influences
soil
material
damping
effect
resonators.
results
indicate
that
from
4.68
Hz
22.01
10-cycle
resonators
could
Raleigh
Furthermore,
band
1.96
20
Hz,
whereas
has
little
propagation
These
show
this
mitigate
provide
reference
for
design
barrier
structures.
Materials,
Год журнала:
2025,
Номер
18(2), С. 363 - 363
Опубликована: Янв. 15, 2025
This
paper
focuses
on
the
theoretical
and
analytical
modeling
of
a
novel
seismic
isolator
termed
Passive
Friction
Mechanical
Metamaterial
Seismic
Isolator
(PFSMBI)
system,
which
is
designed
for
hazard
mitigation
in
multi-story
buildings.
The
PFSMBI
system
consists
lattice
structure
composed
series
identical
small
cells
interconnected
by
layers
made
viscoelastic
materials.
main
function
to
shift
fundamental
natural
frequency
building
away
from
dominant
earthquake
excitations
creating
low-frequency
bandgaps
(FBGs)
below
20
Hz.
In
this
configuration,
each
unit
cell
contains
an
inner
resonator
that
slides
over
friction
surface
while
it
tuned
vibrate
at
building.
resonance
enhances
energy
dissipation
capacity
system.
After
deriving
governing
equations
four
selected
configurations
(i.e.,
Cases
1–4),
parametric
study
performed
optimize
wide
range
harmonic
ground
motion
frequencies.
study,
we
examine
how
key
parameters,
such
as
mass
ratios
resonators,
tuning
ratios,
number
cells,
coefficient
friction,
affect
system’s
performance.
then
incorporated
into
dynamic
model
six-story
base-isolated
evaluate
its
effectiveness
reducing
floor
acceleration
inter-story
drift
under
actual
records.
used
investigate
effect
stick–slip
(SSM)
performance
employing
LuGre
model.
numerical
results
show
optimized
through
frictional
effectively
reduces
leveraging
FBGs
dissipation,
particularly
when
SSM
effects
are
properly
accounted
for.
Finally,
small-scale
prototype
with
two
developed
verify
SSM.
experimental
validation
highlights
neglecting
can
lead
overestimation
systems.
Physical review. B./Physical review. B,
Год журнала:
2024,
Номер
109(2)
Опубликована: Янв. 18, 2024
In
this
paper,
the
effects
of
rotation
on
a
phononic
crystal
(PnC)
operated
in
whispering-gallery
modes
(WGMs)
are
investigated
for
first
time.
According
to
results
finite
element
method,
vibration
pattern
WGMs
under
action
will
undergo
linear
precession
with
integral
rotation,
which
agrees
theoretical
models.
addition,
linearly
induce
phase
difference
between
transmissive
waves
fixed
gain.
The
displacement
is
utilized
characterize
wave,
showing
periodicity,
linearity,
and
directionality
as
predictions.
These
findings
offer
rate-integrating
scheme
sense
have
promising
applications,
especially
high-performance
SAW
gyroscopes.
