Metal Foams: A Design Guide

Weight index
ψ = W/2πR 2 ρ s
W core /W
0.004
0.003
0.002
0.001
0
0
0.8
0.6
0.4
0.2
0
0
a
b
Axially stiffened
shell ( /R = 1)
0.2 0.4 0.6 0.8 1 1.2
ρ c/ρ s = 0.05
ρ c /ρ s = 0.1
ρ c /ρ s = 0.05
N/E fR (×10 5 )
Load Index
ρ c /ρ s = 0.1
0.2 0.4 0.6 0.8 1 1.2
N /E fR (×10 5 )
Configuration
N
2R
1.4 1.6 1.8 2
Configuration
N
2R
1.4 1.6 1.8 2
Sandwich structures 143
Figure 10.16 (a) Weight index versus load index for cylindrical sandwich
shells. (b) Relative weight versus load index for cylindrical sandwich shells
design has no relevance. For reference, the result for the optimally designed
cylindrical shell with axial hat-stiffeners is repeated from Figure 10.16(a).
This comparison illustrates the weight superiority of foam metal-core sandwich
shells over conventional shell construction as well as the potential benefit
to be gained by using a core material with the best available stiffness.