2.1 Consider the
revised model shown in Figure 4.2.1 Sandwich panel example model:
|
b
|
= |
breadth
in direction of bending = 700 mm |
|
G
|
= |
shear
modulus for 100 kg/m3 core
|
|
|
= |
36 N/mm2 being
90 per cent of the manufacturer’s quoted value
|
|
t
S
|
= |
mean skin thickness (3,56 + 4,67)/2 = 4,11 mm |
|
(1 –v
f
2)
|
= |
unity (approximately) |
| = |
Calculation of deflection in accordance with
Pt 8, Ch 3, Pt 8, Ch 3, 1 General of the Rules
for Special Service Craft
|
2.2 The total deflection
comprises 23 per cent due to bending and 77 per cent due to shear.
2.3 The deflection criterion is given inTable 7.2.1 Limiting span/deflection
ratio Pt 8, Ch 7 of the Rules
for Special Service Craft.
Hence the 2,2 mm total deflection is acceptable.
Figure 4.2.1 Sandwich panel example model