Composite Materials Research Progress

Optimization of Laminated Composite Structures… 91
4
3.5
3
2.5
2
1.5
1
Evolution of the strain
energy density
Laminate configuration
for the several load
cases
0.5
0 1 2 3 4 5 6 7 8
Load parameter k
Figure 8.13. Variation of the strain energy density and configuration of the corresponding optimal
laminate.
Figure 8.14. Evolution of the strain energy densities for the [0/90]S laminate Subjected to
( N 1 , N 2 , N6
) = ( 0,
1000,
0)
N / mm and ( N 1 , N 2 , N6
) = ( 1000,
0,
0)
N / mm . t0° and t90° are the plies
thickness.
The variation of the strain energy density for each single load case is illustrated in
Figures 8.15 and 8.16. In those particular cases, the optimal solutions are given by only 90° or
0° orientations. This illustrates the need for a multi-objective formulation when several
functions are considered as objective.