Page 76 - Kutnar, Andreja, et al., eds., 2015. Proceedings of the 1st COST Action FP1307 International Conference - Life Cycle Assessment, EPDs, and modified wood. University of Primorska Press, Koper.
P. 76
e,
temperature
is
assumed
to
be
constant.
The
properties
of
the
MMCG
specimen
are
summarized
in
Table
1.
Fig.
2
shows
the
evolutions
of
viscoelastic
energy
release
rate
in
opening
mode
G1
and
shear
mode
G2
versus
time
using
!
integral,
under
moisture
level
variation.
We
note
an
increase
of
G
with
the
moisture
level.
Hence,
for
both
modes,
we
can
observe
at
first,
a
progressive
increase
of
G,
and
then,
a
stationary
phase
with
a
stabilization
of
its
evolution.
Specifically,
we
can
observe,
for
G2,
a
highest
energy
release
rate
than
G1.
A
regular
trend
in
viscoelastic
energy
levels
illustrate
the
moisture
effect
stability
in
mixed
mode
calculated
with
the
integral
!
without
taking
into
account
the
effect
of
thermal
expansion
induced
by
a
change
of
the
temperature
field.
Table
1:
Elastic
properties
of
MMCG
specimen
Elastic
constant
Value
of
elastic
constants
Transversal
Young's
modulus
!()
Longitudinal
Young's
modulus
!()
1500
Shear
modulus
!"()
600
Poisson's
ratio
!"
700
0.4
(a) (b)
Figure
2:
Viscoelastic
energy
release
rate
in
opening
mode
(a)
and
shear
mode
(b).
References
Moutou
Pitti
R.,
Fournely
E.,
Hamdi
S.E,
Ekomy
Ango
S.
2014.
Performance
Testing
and
Testing
Methodologies,
COST
ACTION
FP1303,
Tallinn,
4-‐5.
Riahi
H.,
Moutou
Pitti
R.,
Dubois
F.,
Fournely
E.
2015.
On
numerical
evaluation
of
mixed
mode
crack
propagation
coupling
mechanical
and
thermal
loads
in
wood
material.
Springer,
5
:
21-‐
26.
Moutou
Pitti
R.,
Toussaint
E.,
Fournely
E.,
Grédiac
M.
2014.
Applying
the
grid
method
to
investigate
crack
appearance
and
propagation
in
notched
wood
beams
used
in
individual
houses
in
Europe.
COST
ACTION
FP1303.
1st
Conference. Kranjska
Gora,
Slovenia
23-‐24
October.
Acknowledgments:
The
authors
wish
to
strongly
acknowledge
the
National
Agency
of
Research
(ANR)
for
its
financial
support
of
this
work
through
the
project
CLIMBOIS
N°
ANR-‐13-‐JS09-‐0003-‐01
labeled
by
ViaMeca.
64
temperature
is
assumed
to
be
constant.
The
properties
of
the
MMCG
specimen
are
summarized
in
Table
1.
Fig.
2
shows
the
evolutions
of
viscoelastic
energy
release
rate
in
opening
mode
G1
and
shear
mode
G2
versus
time
using
!
integral,
under
moisture
level
variation.
We
note
an
increase
of
G
with
the
moisture
level.
Hence,
for
both
modes,
we
can
observe
at
first,
a
progressive
increase
of
G,
and
then,
a
stationary
phase
with
a
stabilization
of
its
evolution.
Specifically,
we
can
observe,
for
G2,
a
highest
energy
release
rate
than
G1.
A
regular
trend
in
viscoelastic
energy
levels
illustrate
the
moisture
effect
stability
in
mixed
mode
calculated
with
the
integral
!
without
taking
into
account
the
effect
of
thermal
expansion
induced
by
a
change
of
the
temperature
field.
Table
1:
Elastic
properties
of
MMCG
specimen
Elastic
constant
Value
of
elastic
constants
Transversal
Young's
modulus
!()
Longitudinal
Young's
modulus
!()
1500
Shear
modulus
!"()
600
Poisson's
ratio
!"
700
0.4
(a) (b)
Figure
2:
Viscoelastic
energy
release
rate
in
opening
mode
(a)
and
shear
mode
(b).
References
Moutou
Pitti
R.,
Fournely
E.,
Hamdi
S.E,
Ekomy
Ango
S.
2014.
Performance
Testing
and
Testing
Methodologies,
COST
ACTION
FP1303,
Tallinn,
4-‐5.
Riahi
H.,
Moutou
Pitti
R.,
Dubois
F.,
Fournely
E.
2015.
On
numerical
evaluation
of
mixed
mode
crack
propagation
coupling
mechanical
and
thermal
loads
in
wood
material.
Springer,
5
:
21-‐
26.
Moutou
Pitti
R.,
Toussaint
E.,
Fournely
E.,
Grédiac
M.
2014.
Applying
the
grid
method
to
investigate
crack
appearance
and
propagation
in
notched
wood
beams
used
in
individual
houses
in
Europe.
COST
ACTION
FP1303.
1st
Conference. Kranjska
Gora,
Slovenia
23-‐24
October.
Acknowledgments:
The
authors
wish
to
strongly
acknowledge
the
National
Agency
of
Research
(ANR)
for
its
financial
support
of
this
work
through
the
project
CLIMBOIS
N°
ANR-‐13-‐JS09-‐0003-‐01
labeled
by
ViaMeca.
64
