Abstract
The present paper proposes a novel approach to the determination of moderately complex shapes that satisfy the requirement for lightweight, high stiffness and enough strength. The parameter CD (curvature deviation) which represents the degree of structural shape complexity is introduced. A smoother shape is derived by an evolutional change of CD, while a structural shape is obtained by an iterative change of an allowable stress region based on the fully stressed design. The proposed method has been verified by applying it to the design of a hook.