An adaptation of genetic algorithms as an optimization tool for large-
scale multidisciplinary design problems is described. The design of a
hingeless composite rotor blade is used as a test bed for this class o
f problems, where the formulation of the objective and constraint func
tions requires the consideration of disciplines of aerodynamics, perfo
rmance, dynamics, and structures. A rational decomposition approach ba
sed on the use of neural networks is proposed for partitioning the lar
ge-scale multidisciplinary design problem into smaller, more tractable
subproblems. A design method based on a parallel implementation of ge
netic algorithms is shown to be an effective strategy, providing incre
ased computational efficiency, and a natural approach to account for t
he coupling between temporarily decoupled subproblems.