Abstract: In order to study the placement manufacturability of fixed-angle automated fiber placement trajectory for composite conical shell, this paper proposes a new evaluation criterion for placement manufacturability based on the compressive strain of prepreg strands. As the compressive strain depends considerably on geodesic curvature of trajectory, the formula for geodesic curvature of conical logarithmic spiral is derived by proving the equivalence of conical logarithmic spiral and fixed-angle trajectory. The formula shows that compressive strain of prepreg strands on fixed-angle trajectory decreases with the diameter of the conic section, and increases with the laying angle and the cone angle. The proposal is validated by practical placement experiment using X850 prepreg.

Key words: composite materials, automated fiber placement, fixed-angle, geodesic curvature, manufacturability