Résumé
Wooden p
anel paintings
from cultural heritage
are excellent
case of study for an engineer.
They are
witness
of ancient
times and practices
,
and may provide keys
to the understanding of
long term behaviour
of wooden structures
[1
,2
]
.
A
particularity
of
these objects is the
permanent cupping of the panel. It
seems to
appear
whatever the orientation of the panel
cutting (quatersawn or flatsawn
) and the position of the paint layer. One of the possible origin
of this cupping is
the
compression
-
set
[
3
]
, due t
o
a combination of
mechano
-
sorptive
and
plastic
behaviour
of wood
.
This phenomenon is more severe
when
the panel is restrained, so
that
shrinkage and swelling are
prevented
and stress
es
generated during
cycling change
s
of
humidity
lead to cracking of the
wooden support
.
For our study, we try to reproduce a panel mock
-
up, taking care to characterize each
component
at each
step until the final result: a permanent
ly
cupped
panel.
In the presentation
we
will introduce t
he first step
, where
the sorption
al
and m
echanical behaviour of a
‘
naked
’
(uncoated)
panel
is monitored using image correlation techniques and continuous weighting.