An iso-contour method for automated fiber placement optimization of composite structures

A new method for numerical optimization of fiber-steered composites is presented, which allows to control efficiently and effectively the curvature of the fibers of single- or multi-layer composite structures. It is based on the introduction of an artificial surface defined and controlled by a relatively small number of control points, which is optimized to identify optimal fiber orientations varying smoothly over the panels. Curvature constraints like the maximum fiber curvature constraint, MFCC, or the average fiber curvature constraint, AFCC, are respected explicitly by the method to ensure manufacturability of the composite component. Three validation cases are regarded where results of the unconstrained case are compared to those of established methods to illustrate the validity of the new approach. They are complemented by results considering curvature constraints showing that optimal structures depend strongly on the chosen curvature thresholds. Finally, a rib optimization of a wingbox structure is realized as a more complex case.