arXiv (Cornell University),
Journal Year:
2023,
Volume and Issue:
unknown
Published: Jan. 1, 2023
Single-molecule
stretching
experiments
are
widely
utilized
within
the
fields
of
physics
and
chemistry
to
characterize
mechanics
individual
bonds
or
molecules,
as
well
chemical
reactions.
Analytic
relations
describing
these
valuable,
can
be
obtained
through
statistical
thermodynamics
idealized
model
systems
representing
experiments.
Since
specific
thermodynamic
ensembles
manifested
by
affect
outcome,
primarily
for
small
device
must
included
in
system.
Though
stretched
molecule
might
exactly
solvable,
including
often
prevents
analytic
solutions.
In
limit
large
stiffness,
isometric
isotensional
provide
effective
approximations,
but
effects
missing.
Here,
a
dual
set
asymptotically
correct
theories
applied
develop
accurate
approximations
full
system
that
includes
both
device.
The
asymptotic
first
demonstrated
using
freely
jointed
chain
model,
then
molecular
dynamics
calculations
single
polyethylene
chain.
Advanced Functional Materials,
Journal Year:
2024,
Volume and Issue:
34(46)
Published: June 19, 2024
Abstract
Highly
cross‐linked
thermosets
possess
superior
mechanical
properties
and
have
found
broad
applications
in
engineering.
However,
due
to
the
dense
cross‐links,
it
is
extremely
challenging
recycle
highly
thermosets,
causing
serious
environmental
sustainable
concerns.
Herein,
a
mechanochemical
recycling
strategy
proposed
for
via
synergy
of
mechanics
chemistry,
which
economic‐friendly
pollution‐free.
To
demonstrate
strategy,
diverse
metal‐complex
catalysts
are
employed
epoxy
incorporated
with
switchable
covalent
bonds
at
certain
pressure,
temperature,
time.
The
effect
each
catalyst
on
efficiency
evaluated,
follows
descending
order:
Zr
4+
>
Mn
3+
Co
Fe
2+
Zn
OTi
Ni
.
results
show
that
properties,
such
as
Young's
modulus,
ultimate
strength,
peak
strain,
impact
flexural
modulus
well
thermal
stability
recycled
samples
almost
identical
those
as‐synthesized
ones.
effectiveness
method
further
confirmed
micromorphology.
This
article
reports
an
improved
Taylor
approximation
of
the
Arruda-Boyce
model.
Aided
by
recurrence
relationships
for
inverse
Langevin
function,
this
new
expansion
can
be
used
to
replace
current
5-term
model
in
finite-element
codes
such
as
Abaqus
and
Ls-Dyna.
The
will
improve
accuracy
large-deformation
simulations,
where
is
insufficient.
Journal of Applied Mechanics,
Journal Year:
2024,
Volume and Issue:
91(12)
Published: Aug. 29, 2024
Abstract
Recently,
the
phase-field
method
has
been
increasingly
used
for
brittle
fractures
in
soft
materials
like
polymers,
elastomers,
and
biological
tissues.
When
considering
finite
deformations
to
account
highly
deformable
nature
of
materials,
convergence
becomes
challenging,
especially
scenarios
unstable
crack
growth.
To
overcome
these
numerical
difficulties,
several
approaches
have
introduced,
with
artificial
viscosity
being
most
widely
utilized.
This
study
investigates
energy
release
rate
due
propagation
hyperelastic
nearly-incompressible
compares
a
novel
gradient-enhanced
damage
(GED)
approach.
First,
we
simulate
loading
using
method,
which
leads
problems.
address
issues,
introduce
stabilize
problem
analyze
its
impact
on
utilizing
domain
J-integral
approach
giving
quantitative
measurements
during
propagation.
It
is
observed
that
measured
released
does
not
comply
imposed
critical
rate,
shows
non-monotonic
behavior.
In
second
part
paper,
stretch-based
GED
model
as
an
alternative
modeling
evolution
elastomers.
demonstrated
this
can
be
obtained
output
simulation
rather
than
input
could
useful
exploration
rate-dependent
responses,
one
directly
impose
chain-level
criteria
initiation.
We
show
while
provides
reasonable
results
fracture
simulations,
it
still
suffers
from
some
issues
strain-based
formulations
are
known
susceptible
to.
