where
Es is the compressive modulus of skins, in O° and 90° in-plane axis of panel, N/mm2;
Ec is the compressive modulus of core, perpendicular to skins, N/mm2;
Gc is the core shear modulus, in the direction parallel to load, N/mm2.
7.1.2.4 Minimum skin thickness
After all other requirements are met, the thickness of the outer skin, tos, and inner skin, tis, shall in general not be less than given by the following equations:
tos = 0,35・k4'(c1 + 0,26・Lwl) (25)
tis = 0,25・k4'(c1 + 0,26・Lwl) (26)
where
tos is the thickness of the outer skin, in millimetres;
tis is the thickness of the inner skin, in millimetres;
k4 = 1,1 for bottom shell;
= 1,0 for side shell and deck;
C1 = 3,2 mm.
Consideration shall be given to lesser values of c1 for vessels limited to service in sheltered waters.
Where advanced fibres are used, this minimum thickness requirement does not apply. Special consideration has to be given in accordance with the required mechanical properties of the laminate.
