Reformulation of the elasticity matrix
L
i
j
k
l
=
L
K
L
Where:
K
=
i
if
i
=
j
K
=
9
-
(
i
+
j
)
if
i
≠
j
And:
L
=
k
if
k
=
l
L
=
9
-
(
k
+
l
)
if
k
≠
l